About Kernel Documentation Linux Kernel Contact Linux Resources Linux Blog

Documentation / virtual / kvm / api.txt




Custom Search

Based on kernel version 3.13. Page generated on 2014-01-20 22:05 EST.

1	The Definitive KVM (Kernel-based Virtual Machine) API Documentation
2	===================================================================
3	
4	1. General description
5	----------------------
6	
7	The kvm API is a set of ioctls that are issued to control various aspects
8	of a virtual machine.  The ioctls belong to three classes
9	
10	 - System ioctls: These query and set global attributes which affect the
11	   whole kvm subsystem.  In addition a system ioctl is used to create
12	   virtual machines
13	
14	 - VM ioctls: These query and set attributes that affect an entire virtual
15	   machine, for example memory layout.  In addition a VM ioctl is used to
16	   create virtual cpus (vcpus).
17	
18	   Only run VM ioctls from the same process (address space) that was used
19	   to create the VM.
20	
21	 - vcpu ioctls: These query and set attributes that control the operation
22	   of a single virtual cpu.
23	
24	   Only run vcpu ioctls from the same thread that was used to create the
25	   vcpu.
26	
27	
28	2. File descriptors
29	-------------------
30	
31	The kvm API is centered around file descriptors.  An initial
32	open("/dev/kvm") obtains a handle to the kvm subsystem; this handle
33	can be used to issue system ioctls.  A KVM_CREATE_VM ioctl on this
34	handle will create a VM file descriptor which can be used to issue VM
35	ioctls.  A KVM_CREATE_VCPU ioctl on a VM fd will create a virtual cpu
36	and return a file descriptor pointing to it.  Finally, ioctls on a vcpu
37	fd can be used to control the vcpu, including the important task of
38	actually running guest code.
39	
40	In general file descriptors can be migrated among processes by means
41	of fork() and the SCM_RIGHTS facility of unix domain socket.  These
42	kinds of tricks are explicitly not supported by kvm.  While they will
43	not cause harm to the host, their actual behavior is not guaranteed by
44	the API.  The only supported use is one virtual machine per process,
45	and one vcpu per thread.
46	
47	
48	3. Extensions
49	-------------
50	
51	As of Linux 2.6.22, the KVM ABI has been stabilized: no backward
52	incompatible change are allowed.  However, there is an extension
53	facility that allows backward-compatible extensions to the API to be
54	queried and used.
55	
56	The extension mechanism is not based on the Linux version number.
57	Instead, kvm defines extension identifiers and a facility to query
58	whether a particular extension identifier is available.  If it is, a
59	set of ioctls is available for application use.
60	
61	
62	4. API description
63	------------------
64	
65	This section describes ioctls that can be used to control kvm guests.
66	For each ioctl, the following information is provided along with a
67	description:
68	
69	  Capability: which KVM extension provides this ioctl.  Can be 'basic',
70	      which means that is will be provided by any kernel that supports
71	      API version 12 (see section 4.1), or a KVM_CAP_xyz constant, which
72	      means availability needs to be checked with KVM_CHECK_EXTENSION
73	      (see section 4.4).
74	
75	  Architectures: which instruction set architectures provide this ioctl.
76	      x86 includes both i386 and x86_64.
77	
78	  Type: system, vm, or vcpu.
79	
80	  Parameters: what parameters are accepted by the ioctl.
81	
82	  Returns: the return value.  General error numbers (EBADF, ENOMEM, EINVAL)
83	      are not detailed, but errors with specific meanings are.
84	
85	
86	4.1 KVM_GET_API_VERSION
87	
88	Capability: basic
89	Architectures: all
90	Type: system ioctl
91	Parameters: none
92	Returns: the constant KVM_API_VERSION (=12)
93	
94	This identifies the API version as the stable kvm API. It is not
95	expected that this number will change.  However, Linux 2.6.20 and
96	2.6.21 report earlier versions; these are not documented and not
97	supported.  Applications should refuse to run if KVM_GET_API_VERSION
98	returns a value other than 12.  If this check passes, all ioctls
99	described as 'basic' will be available.
100	
101	
102	4.2 KVM_CREATE_VM
103	
104	Capability: basic
105	Architectures: all
106	Type: system ioctl
107	Parameters: machine type identifier (KVM_VM_*)
108	Returns: a VM fd that can be used to control the new virtual machine.
109	
110	The new VM has no virtual cpus and no memory.  An mmap() of a VM fd
111	will access the virtual machine's physical address space; offset zero
112	corresponds to guest physical address zero.  Use of mmap() on a VM fd
113	is discouraged if userspace memory allocation (KVM_CAP_USER_MEMORY) is
114	available.
115	You most certainly want to use 0 as machine type.
116	
117	In order to create user controlled virtual machines on S390, check
118	KVM_CAP_S390_UCONTROL and use the flag KVM_VM_S390_UCONTROL as
119	privileged user (CAP_SYS_ADMIN).
120	
121	
122	4.3 KVM_GET_MSR_INDEX_LIST
123	
124	Capability: basic
125	Architectures: x86
126	Type: system
127	Parameters: struct kvm_msr_list (in/out)
128	Returns: 0 on success; -1 on error
129	Errors:
130	  E2BIG:     the msr index list is to be to fit in the array specified by
131	             the user.
132	
133	struct kvm_msr_list {
134		__u32 nmsrs; /* number of msrs in entries */
135		__u32 indices[0];
136	};
137	
138	This ioctl returns the guest msrs that are supported.  The list varies
139	by kvm version and host processor, but does not change otherwise.  The
140	user fills in the size of the indices array in nmsrs, and in return
141	kvm adjusts nmsrs to reflect the actual number of msrs and fills in
142	the indices array with their numbers.
143	
144	Note: if kvm indicates supports MCE (KVM_CAP_MCE), then the MCE bank MSRs are
145	not returned in the MSR list, as different vcpus can have a different number
146	of banks, as set via the KVM_X86_SETUP_MCE ioctl.
147	
148	
149	4.4 KVM_CHECK_EXTENSION
150	
151	Capability: basic
152	Architectures: all
153	Type: system ioctl
154	Parameters: extension identifier (KVM_CAP_*)
155	Returns: 0 if unsupported; 1 (or some other positive integer) if supported
156	
157	The API allows the application to query about extensions to the core
158	kvm API.  Userspace passes an extension identifier (an integer) and
159	receives an integer that describes the extension availability.
160	Generally 0 means no and 1 means yes, but some extensions may report
161	additional information in the integer return value.
162	
163	
164	4.5 KVM_GET_VCPU_MMAP_SIZE
165	
166	Capability: basic
167	Architectures: all
168	Type: system ioctl
169	Parameters: none
170	Returns: size of vcpu mmap area, in bytes
171	
172	The KVM_RUN ioctl (cf.) communicates with userspace via a shared
173	memory region.  This ioctl returns the size of that region.  See the
174	KVM_RUN documentation for details.
175	
176	
177	4.6 KVM_SET_MEMORY_REGION
178	
179	Capability: basic
180	Architectures: all
181	Type: vm ioctl
182	Parameters: struct kvm_memory_region (in)
183	Returns: 0 on success, -1 on error
184	
185	This ioctl is obsolete and has been removed.
186	
187	
188	4.7 KVM_CREATE_VCPU
189	
190	Capability: basic
191	Architectures: all
192	Type: vm ioctl
193	Parameters: vcpu id (apic id on x86)
194	Returns: vcpu fd on success, -1 on error
195	
196	This API adds a vcpu to a virtual machine.  The vcpu id is a small integer
197	in the range [0, max_vcpus).
198	
199	The recommended max_vcpus value can be retrieved using the KVM_CAP_NR_VCPUS of
200	the KVM_CHECK_EXTENSION ioctl() at run-time.
201	The maximum possible value for max_vcpus can be retrieved using the
202	KVM_CAP_MAX_VCPUS of the KVM_CHECK_EXTENSION ioctl() at run-time.
203	
204	If the KVM_CAP_NR_VCPUS does not exist, you should assume that max_vcpus is 4
205	cpus max.
206	If the KVM_CAP_MAX_VCPUS does not exist, you should assume that max_vcpus is
207	same as the value returned from KVM_CAP_NR_VCPUS.
208	
209	On powerpc using book3s_hv mode, the vcpus are mapped onto virtual
210	threads in one or more virtual CPU cores.  (This is because the
211	hardware requires all the hardware threads in a CPU core to be in the
212	same partition.)  The KVM_CAP_PPC_SMT capability indicates the number
213	of vcpus per virtual core (vcore).  The vcore id is obtained by
214	dividing the vcpu id by the number of vcpus per vcore.  The vcpus in a
215	given vcore will always be in the same physical core as each other
216	(though that might be a different physical core from time to time).
217	Userspace can control the threading (SMT) mode of the guest by its
218	allocation of vcpu ids.  For example, if userspace wants
219	single-threaded guest vcpus, it should make all vcpu ids be a multiple
220	of the number of vcpus per vcore.
221	
222	For virtual cpus that have been created with S390 user controlled virtual
223	machines, the resulting vcpu fd can be memory mapped at page offset
224	KVM_S390_SIE_PAGE_OFFSET in order to obtain a memory map of the virtual
225	cpu's hardware control block.
226	
227	
228	4.8 KVM_GET_DIRTY_LOG (vm ioctl)
229	
230	Capability: basic
231	Architectures: x86
232	Type: vm ioctl
233	Parameters: struct kvm_dirty_log (in/out)
234	Returns: 0 on success, -1 on error
235	
236	/* for KVM_GET_DIRTY_LOG */
237	struct kvm_dirty_log {
238		__u32 slot;
239		__u32 padding;
240		union {
241			void __user *dirty_bitmap; /* one bit per page */
242			__u64 padding;
243		};
244	};
245	
246	Given a memory slot, return a bitmap containing any pages dirtied
247	since the last call to this ioctl.  Bit 0 is the first page in the
248	memory slot.  Ensure the entire structure is cleared to avoid padding
249	issues.
250	
251	
252	4.9 KVM_SET_MEMORY_ALIAS
253	
254	Capability: basic
255	Architectures: x86
256	Type: vm ioctl
257	Parameters: struct kvm_memory_alias (in)
258	Returns: 0 (success), -1 (error)
259	
260	This ioctl is obsolete and has been removed.
261	
262	
263	4.10 KVM_RUN
264	
265	Capability: basic
266	Architectures: all
267	Type: vcpu ioctl
268	Parameters: none
269	Returns: 0 on success, -1 on error
270	Errors:
271	  EINTR:     an unmasked signal is pending
272	
273	This ioctl is used to run a guest virtual cpu.  While there are no
274	explicit parameters, there is an implicit parameter block that can be
275	obtained by mmap()ing the vcpu fd at offset 0, with the size given by
276	KVM_GET_VCPU_MMAP_SIZE.  The parameter block is formatted as a 'struct
277	kvm_run' (see below).
278	
279	
280	4.11 KVM_GET_REGS
281	
282	Capability: basic
283	Architectures: all except ARM, arm64
284	Type: vcpu ioctl
285	Parameters: struct kvm_regs (out)
286	Returns: 0 on success, -1 on error
287	
288	Reads the general purpose registers from the vcpu.
289	
290	/* x86 */
291	struct kvm_regs {
292		/* out (KVM_GET_REGS) / in (KVM_SET_REGS) */
293		__u64 rax, rbx, rcx, rdx;
294		__u64 rsi, rdi, rsp, rbp;
295		__u64 r8,  r9,  r10, r11;
296		__u64 r12, r13, r14, r15;
297		__u64 rip, rflags;
298	};
299	
300	
301	4.12 KVM_SET_REGS
302	
303	Capability: basic
304	Architectures: all except ARM, arm64
305	Type: vcpu ioctl
306	Parameters: struct kvm_regs (in)
307	Returns: 0 on success, -1 on error
308	
309	Writes the general purpose registers into the vcpu.
310	
311	See KVM_GET_REGS for the data structure.
312	
313	
314	4.13 KVM_GET_SREGS
315	
316	Capability: basic
317	Architectures: x86, ppc
318	Type: vcpu ioctl
319	Parameters: struct kvm_sregs (out)
320	Returns: 0 on success, -1 on error
321	
322	Reads special registers from the vcpu.
323	
324	/* x86 */
325	struct kvm_sregs {
326		struct kvm_segment cs, ds, es, fs, gs, ss;
327		struct kvm_segment tr, ldt;
328		struct kvm_dtable gdt, idt;
329		__u64 cr0, cr2, cr3, cr4, cr8;
330		__u64 efer;
331		__u64 apic_base;
332		__u64 interrupt_bitmap[(KVM_NR_INTERRUPTS + 63) / 64];
333	};
334	
335	/* ppc -- see arch/powerpc/include/uapi/asm/kvm.h */
336	
337	interrupt_bitmap is a bitmap of pending external interrupts.  At most
338	one bit may be set.  This interrupt has been acknowledged by the APIC
339	but not yet injected into the cpu core.
340	
341	
342	4.14 KVM_SET_SREGS
343	
344	Capability: basic
345	Architectures: x86, ppc
346	Type: vcpu ioctl
347	Parameters: struct kvm_sregs (in)
348	Returns: 0 on success, -1 on error
349	
350	Writes special registers into the vcpu.  See KVM_GET_SREGS for the
351	data structures.
352	
353	
354	4.15 KVM_TRANSLATE
355	
356	Capability: basic
357	Architectures: x86
358	Type: vcpu ioctl
359	Parameters: struct kvm_translation (in/out)
360	Returns: 0 on success, -1 on error
361	
362	Translates a virtual address according to the vcpu's current address
363	translation mode.
364	
365	struct kvm_translation {
366		/* in */
367		__u64 linear_address;
368	
369		/* out */
370		__u64 physical_address;
371		__u8  valid;
372		__u8  writeable;
373		__u8  usermode;
374		__u8  pad[5];
375	};
376	
377	
378	4.16 KVM_INTERRUPT
379	
380	Capability: basic
381	Architectures: x86, ppc
382	Type: vcpu ioctl
383	Parameters: struct kvm_interrupt (in)
384	Returns: 0 on success, -1 on error
385	
386	Queues a hardware interrupt vector to be injected.  This is only
387	useful if in-kernel local APIC or equivalent is not used.
388	
389	/* for KVM_INTERRUPT */
390	struct kvm_interrupt {
391		/* in */
392		__u32 irq;
393	};
394	
395	X86:
396	
397	Note 'irq' is an interrupt vector, not an interrupt pin or line.
398	
399	PPC:
400	
401	Queues an external interrupt to be injected. This ioctl is overleaded
402	with 3 different irq values:
403	
404	a) KVM_INTERRUPT_SET
405	
406	  This injects an edge type external interrupt into the guest once it's ready
407	  to receive interrupts. When injected, the interrupt is done.
408	
409	b) KVM_INTERRUPT_UNSET
410	
411	  This unsets any pending interrupt.
412	
413	  Only available with KVM_CAP_PPC_UNSET_IRQ.
414	
415	c) KVM_INTERRUPT_SET_LEVEL
416	
417	  This injects a level type external interrupt into the guest context. The
418	  interrupt stays pending until a specific ioctl with KVM_INTERRUPT_UNSET
419	  is triggered.
420	
421	  Only available with KVM_CAP_PPC_IRQ_LEVEL.
422	
423	Note that any value for 'irq' other than the ones stated above is invalid
424	and incurs unexpected behavior.
425	
426	
427	4.17 KVM_DEBUG_GUEST
428	
429	Capability: basic
430	Architectures: none
431	Type: vcpu ioctl
432	Parameters: none)
433	Returns: -1 on error
434	
435	Support for this has been removed.  Use KVM_SET_GUEST_DEBUG instead.
436	
437	
438	4.18 KVM_GET_MSRS
439	
440	Capability: basic
441	Architectures: x86
442	Type: vcpu ioctl
443	Parameters: struct kvm_msrs (in/out)
444	Returns: 0 on success, -1 on error
445	
446	Reads model-specific registers from the vcpu.  Supported msr indices can
447	be obtained using KVM_GET_MSR_INDEX_LIST.
448	
449	struct kvm_msrs {
450		__u32 nmsrs; /* number of msrs in entries */
451		__u32 pad;
452	
453		struct kvm_msr_entry entries[0];
454	};
455	
456	struct kvm_msr_entry {
457		__u32 index;
458		__u32 reserved;
459		__u64 data;
460	};
461	
462	Application code should set the 'nmsrs' member (which indicates the
463	size of the entries array) and the 'index' member of each array entry.
464	kvm will fill in the 'data' member.
465	
466	
467	4.19 KVM_SET_MSRS
468	
469	Capability: basic
470	Architectures: x86
471	Type: vcpu ioctl
472	Parameters: struct kvm_msrs (in)
473	Returns: 0 on success, -1 on error
474	
475	Writes model-specific registers to the vcpu.  See KVM_GET_MSRS for the
476	data structures.
477	
478	Application code should set the 'nmsrs' member (which indicates the
479	size of the entries array), and the 'index' and 'data' members of each
480	array entry.
481	
482	
483	4.20 KVM_SET_CPUID
484	
485	Capability: basic
486	Architectures: x86
487	Type: vcpu ioctl
488	Parameters: struct kvm_cpuid (in)
489	Returns: 0 on success, -1 on error
490	
491	Defines the vcpu responses to the cpuid instruction.  Applications
492	should use the KVM_SET_CPUID2 ioctl if available.
493	
494	
495	struct kvm_cpuid_entry {
496		__u32 function;
497		__u32 eax;
498		__u32 ebx;
499		__u32 ecx;
500		__u32 edx;
501		__u32 padding;
502	};
503	
504	/* for KVM_SET_CPUID */
505	struct kvm_cpuid {
506		__u32 nent;
507		__u32 padding;
508		struct kvm_cpuid_entry entries[0];
509	};
510	
511	
512	4.21 KVM_SET_SIGNAL_MASK
513	
514	Capability: basic
515	Architectures: x86
516	Type: vcpu ioctl
517	Parameters: struct kvm_signal_mask (in)
518	Returns: 0 on success, -1 on error
519	
520	Defines which signals are blocked during execution of KVM_RUN.  This
521	signal mask temporarily overrides the threads signal mask.  Any
522	unblocked signal received (except SIGKILL and SIGSTOP, which retain
523	their traditional behaviour) will cause KVM_RUN to return with -EINTR.
524	
525	Note the signal will only be delivered if not blocked by the original
526	signal mask.
527	
528	/* for KVM_SET_SIGNAL_MASK */
529	struct kvm_signal_mask {
530		__u32 len;
531		__u8  sigset[0];
532	};
533	
534	
535	4.22 KVM_GET_FPU
536	
537	Capability: basic
538	Architectures: x86
539	Type: vcpu ioctl
540	Parameters: struct kvm_fpu (out)
541	Returns: 0 on success, -1 on error
542	
543	Reads the floating point state from the vcpu.
544	
545	/* for KVM_GET_FPU and KVM_SET_FPU */
546	struct kvm_fpu {
547		__u8  fpr[8][16];
548		__u16 fcw;
549		__u16 fsw;
550		__u8  ftwx;  /* in fxsave format */
551		__u8  pad1;
552		__u16 last_opcode;
553		__u64 last_ip;
554		__u64 last_dp;
555		__u8  xmm[16][16];
556		__u32 mxcsr;
557		__u32 pad2;
558	};
559	
560	
561	4.23 KVM_SET_FPU
562	
563	Capability: basic
564	Architectures: x86
565	Type: vcpu ioctl
566	Parameters: struct kvm_fpu (in)
567	Returns: 0 on success, -1 on error
568	
569	Writes the floating point state to the vcpu.
570	
571	/* for KVM_GET_FPU and KVM_SET_FPU */
572	struct kvm_fpu {
573		__u8  fpr[8][16];
574		__u16 fcw;
575		__u16 fsw;
576		__u8  ftwx;  /* in fxsave format */
577		__u8  pad1;
578		__u16 last_opcode;
579		__u64 last_ip;
580		__u64 last_dp;
581		__u8  xmm[16][16];
582		__u32 mxcsr;
583		__u32 pad2;
584	};
585	
586	
587	4.24 KVM_CREATE_IRQCHIP
588	
589	Capability: KVM_CAP_IRQCHIP
590	Architectures: x86, ia64, ARM, arm64
591	Type: vm ioctl
592	Parameters: none
593	Returns: 0 on success, -1 on error
594	
595	Creates an interrupt controller model in the kernel.  On x86, creates a virtual
596	ioapic, a virtual PIC (two PICs, nested), and sets up future vcpus to have a
597	local APIC.  IRQ routing for GSIs 0-15 is set to both PIC and IOAPIC; GSI 16-23
598	only go to the IOAPIC.  On ia64, a IOSAPIC is created. On ARM/arm64, a GIC is
599	created.
600	
601	
602	4.25 KVM_IRQ_LINE
603	
604	Capability: KVM_CAP_IRQCHIP
605	Architectures: x86, ia64, arm, arm64
606	Type: vm ioctl
607	Parameters: struct kvm_irq_level
608	Returns: 0 on success, -1 on error
609	
610	Sets the level of a GSI input to the interrupt controller model in the kernel.
611	On some architectures it is required that an interrupt controller model has
612	been previously created with KVM_CREATE_IRQCHIP.  Note that edge-triggered
613	interrupts require the level to be set to 1 and then back to 0.
614	
615	ARM/arm64 can signal an interrupt either at the CPU level, or at the
616	in-kernel irqchip (GIC), and for in-kernel irqchip can tell the GIC to
617	use PPIs designated for specific cpus.  The irq field is interpreted
618	like this:
619	
620	  bits:  | 31 ... 24 | 23  ... 16 | 15    ...    0 |
621	  field: | irq_type  | vcpu_index |     irq_id     |
622	
623	The irq_type field has the following values:
624	- irq_type[0]: out-of-kernel GIC: irq_id 0 is IRQ, irq_id 1 is FIQ
625	- irq_type[1]: in-kernel GIC: SPI, irq_id between 32 and 1019 (incl.)
626	               (the vcpu_index field is ignored)
627	- irq_type[2]: in-kernel GIC: PPI, irq_id between 16 and 31 (incl.)
628	
629	(The irq_id field thus corresponds nicely to the IRQ ID in the ARM GIC specs)
630	
631	In both cases, level is used to raise/lower the line.
632	
633	struct kvm_irq_level {
634		union {
635			__u32 irq;     /* GSI */
636			__s32 status;  /* not used for KVM_IRQ_LEVEL */
637		};
638		__u32 level;           /* 0 or 1 */
639	};
640	
641	
642	4.26 KVM_GET_IRQCHIP
643	
644	Capability: KVM_CAP_IRQCHIP
645	Architectures: x86, ia64
646	Type: vm ioctl
647	Parameters: struct kvm_irqchip (in/out)
648	Returns: 0 on success, -1 on error
649	
650	Reads the state of a kernel interrupt controller created with
651	KVM_CREATE_IRQCHIP into a buffer provided by the caller.
652	
653	struct kvm_irqchip {
654		__u32 chip_id;  /* 0 = PIC1, 1 = PIC2, 2 = IOAPIC */
655		__u32 pad;
656	        union {
657			char dummy[512];  /* reserving space */
658			struct kvm_pic_state pic;
659			struct kvm_ioapic_state ioapic;
660		} chip;
661	};
662	
663	
664	4.27 KVM_SET_IRQCHIP
665	
666	Capability: KVM_CAP_IRQCHIP
667	Architectures: x86, ia64
668	Type: vm ioctl
669	Parameters: struct kvm_irqchip (in)
670	Returns: 0 on success, -1 on error
671	
672	Sets the state of a kernel interrupt controller created with
673	KVM_CREATE_IRQCHIP from a buffer provided by the caller.
674	
675	struct kvm_irqchip {
676		__u32 chip_id;  /* 0 = PIC1, 1 = PIC2, 2 = IOAPIC */
677		__u32 pad;
678	        union {
679			char dummy[512];  /* reserving space */
680			struct kvm_pic_state pic;
681			struct kvm_ioapic_state ioapic;
682		} chip;
683	};
684	
685	
686	4.28 KVM_XEN_HVM_CONFIG
687	
688	Capability: KVM_CAP_XEN_HVM
689	Architectures: x86
690	Type: vm ioctl
691	Parameters: struct kvm_xen_hvm_config (in)
692	Returns: 0 on success, -1 on error
693	
694	Sets the MSR that the Xen HVM guest uses to initialize its hypercall
695	page, and provides the starting address and size of the hypercall
696	blobs in userspace.  When the guest writes the MSR, kvm copies one
697	page of a blob (32- or 64-bit, depending on the vcpu mode) to guest
698	memory.
699	
700	struct kvm_xen_hvm_config {
701		__u32 flags;
702		__u32 msr;
703		__u64 blob_addr_32;
704		__u64 blob_addr_64;
705		__u8 blob_size_32;
706		__u8 blob_size_64;
707		__u8 pad2[30];
708	};
709	
710	
711	4.29 KVM_GET_CLOCK
712	
713	Capability: KVM_CAP_ADJUST_CLOCK
714	Architectures: x86
715	Type: vm ioctl
716	Parameters: struct kvm_clock_data (out)
717	Returns: 0 on success, -1 on error
718	
719	Gets the current timestamp of kvmclock as seen by the current guest. In
720	conjunction with KVM_SET_CLOCK, it is used to ensure monotonicity on scenarios
721	such as migration.
722	
723	struct kvm_clock_data {
724		__u64 clock;  /* kvmclock current value */
725		__u32 flags;
726		__u32 pad[9];
727	};
728	
729	
730	4.30 KVM_SET_CLOCK
731	
732	Capability: KVM_CAP_ADJUST_CLOCK
733	Architectures: x86
734	Type: vm ioctl
735	Parameters: struct kvm_clock_data (in)
736	Returns: 0 on success, -1 on error
737	
738	Sets the current timestamp of kvmclock to the value specified in its parameter.
739	In conjunction with KVM_GET_CLOCK, it is used to ensure monotonicity on scenarios
740	such as migration.
741	
742	struct kvm_clock_data {
743		__u64 clock;  /* kvmclock current value */
744		__u32 flags;
745		__u32 pad[9];
746	};
747	
748	
749	4.31 KVM_GET_VCPU_EVENTS
750	
751	Capability: KVM_CAP_VCPU_EVENTS
752	Extended by: KVM_CAP_INTR_SHADOW
753	Architectures: x86
754	Type: vm ioctl
755	Parameters: struct kvm_vcpu_event (out)
756	Returns: 0 on success, -1 on error
757	
758	Gets currently pending exceptions, interrupts, and NMIs as well as related
759	states of the vcpu.
760	
761	struct kvm_vcpu_events {
762		struct {
763			__u8 injected;
764			__u8 nr;
765			__u8 has_error_code;
766			__u8 pad;
767			__u32 error_code;
768		} exception;
769		struct {
770			__u8 injected;
771			__u8 nr;
772			__u8 soft;
773			__u8 shadow;
774		} interrupt;
775		struct {
776			__u8 injected;
777			__u8 pending;
778			__u8 masked;
779			__u8 pad;
780		} nmi;
781		__u32 sipi_vector;
782		__u32 flags;
783	};
784	
785	KVM_VCPUEVENT_VALID_SHADOW may be set in the flags field to signal that
786	interrupt.shadow contains a valid state. Otherwise, this field is undefined.
787	
788	
789	4.32 KVM_SET_VCPU_EVENTS
790	
791	Capability: KVM_CAP_VCPU_EVENTS
792	Extended by: KVM_CAP_INTR_SHADOW
793	Architectures: x86
794	Type: vm ioctl
795	Parameters: struct kvm_vcpu_event (in)
796	Returns: 0 on success, -1 on error
797	
798	Set pending exceptions, interrupts, and NMIs as well as related states of the
799	vcpu.
800	
801	See KVM_GET_VCPU_EVENTS for the data structure.
802	
803	Fields that may be modified asynchronously by running VCPUs can be excluded
804	from the update. These fields are nmi.pending and sipi_vector. Keep the
805	corresponding bits in the flags field cleared to suppress overwriting the
806	current in-kernel state. The bits are:
807	
808	KVM_VCPUEVENT_VALID_NMI_PENDING - transfer nmi.pending to the kernel
809	KVM_VCPUEVENT_VALID_SIPI_VECTOR - transfer sipi_vector
810	
811	If KVM_CAP_INTR_SHADOW is available, KVM_VCPUEVENT_VALID_SHADOW can be set in
812	the flags field to signal that interrupt.shadow contains a valid state and
813	shall be written into the VCPU.
814	
815	
816	4.33 KVM_GET_DEBUGREGS
817	
818	Capability: KVM_CAP_DEBUGREGS
819	Architectures: x86
820	Type: vm ioctl
821	Parameters: struct kvm_debugregs (out)
822	Returns: 0 on success, -1 on error
823	
824	Reads debug registers from the vcpu.
825	
826	struct kvm_debugregs {
827		__u64 db[4];
828		__u64 dr6;
829		__u64 dr7;
830		__u64 flags;
831		__u64 reserved[9];
832	};
833	
834	
835	4.34 KVM_SET_DEBUGREGS
836	
837	Capability: KVM_CAP_DEBUGREGS
838	Architectures: x86
839	Type: vm ioctl
840	Parameters: struct kvm_debugregs (in)
841	Returns: 0 on success, -1 on error
842	
843	Writes debug registers into the vcpu.
844	
845	See KVM_GET_DEBUGREGS for the data structure. The flags field is unused
846	yet and must be cleared on entry.
847	
848	
849	4.35 KVM_SET_USER_MEMORY_REGION
850	
851	Capability: KVM_CAP_USER_MEM
852	Architectures: all
853	Type: vm ioctl
854	Parameters: struct kvm_userspace_memory_region (in)
855	Returns: 0 on success, -1 on error
856	
857	struct kvm_userspace_memory_region {
858		__u32 slot;
859		__u32 flags;
860		__u64 guest_phys_addr;
861		__u64 memory_size; /* bytes */
862		__u64 userspace_addr; /* start of the userspace allocated memory */
863	};
864	
865	/* for kvm_memory_region::flags */
866	#define KVM_MEM_LOG_DIRTY_PAGES	(1UL << 0)
867	#define KVM_MEM_READONLY	(1UL << 1)
868	
869	This ioctl allows the user to create or modify a guest physical memory
870	slot.  When changing an existing slot, it may be moved in the guest
871	physical memory space, or its flags may be modified.  It may not be
872	resized.  Slots may not overlap in guest physical address space.
873	
874	Memory for the region is taken starting at the address denoted by the
875	field userspace_addr, which must point at user addressable memory for
876	the entire memory slot size.  Any object may back this memory, including
877	anonymous memory, ordinary files, and hugetlbfs.
878	
879	It is recommended that the lower 21 bits of guest_phys_addr and userspace_addr
880	be identical.  This allows large pages in the guest to be backed by large
881	pages in the host.
882	
883	The flags field supports two flags: KVM_MEM_LOG_DIRTY_PAGES and
884	KVM_MEM_READONLY.  The former can be set to instruct KVM to keep track of
885	writes to memory within the slot.  See KVM_GET_DIRTY_LOG ioctl to know how to
886	use it.  The latter can be set, if KVM_CAP_READONLY_MEM capability allows it,
887	to make a new slot read-only.  In this case, writes to this memory will be
888	posted to userspace as KVM_EXIT_MMIO exits.
889	
890	When the KVM_CAP_SYNC_MMU capability is available, changes in the backing of
891	the memory region are automatically reflected into the guest.  For example, an
892	mmap() that affects the region will be made visible immediately.  Another
893	example is madvise(MADV_DROP).
894	
895	It is recommended to use this API instead of the KVM_SET_MEMORY_REGION ioctl.
896	The KVM_SET_MEMORY_REGION does not allow fine grained control over memory
897	allocation and is deprecated.
898	
899	
900	4.36 KVM_SET_TSS_ADDR
901	
902	Capability: KVM_CAP_SET_TSS_ADDR
903	Architectures: x86
904	Type: vm ioctl
905	Parameters: unsigned long tss_address (in)
906	Returns: 0 on success, -1 on error
907	
908	This ioctl defines the physical address of a three-page region in the guest
909	physical address space.  The region must be within the first 4GB of the
910	guest physical address space and must not conflict with any memory slot
911	or any mmio address.  The guest may malfunction if it accesses this memory
912	region.
913	
914	This ioctl is required on Intel-based hosts.  This is needed on Intel hardware
915	because of a quirk in the virtualization implementation (see the internals
916	documentation when it pops into existence).
917	
918	
919	4.37 KVM_ENABLE_CAP
920	
921	Capability: KVM_CAP_ENABLE_CAP
922	Architectures: ppc, s390
923	Type: vcpu ioctl
924	Parameters: struct kvm_enable_cap (in)
925	Returns: 0 on success; -1 on error
926	
927	+Not all extensions are enabled by default. Using this ioctl the application
928	can enable an extension, making it available to the guest.
929	
930	On systems that do not support this ioctl, it always fails. On systems that
931	do support it, it only works for extensions that are supported for enablement.
932	
933	To check if a capability can be enabled, the KVM_CHECK_EXTENSION ioctl should
934	be used.
935	
936	struct kvm_enable_cap {
937	       /* in */
938	       __u32 cap;
939	
940	The capability that is supposed to get enabled.
941	
942	       __u32 flags;
943	
944	A bitfield indicating future enhancements. Has to be 0 for now.
945	
946	       __u64 args[4];
947	
948	Arguments for enabling a feature. If a feature needs initial values to
949	function properly, this is the place to put them.
950	
951	       __u8  pad[64];
952	};
953	
954	
955	4.38 KVM_GET_MP_STATE
956	
957	Capability: KVM_CAP_MP_STATE
958	Architectures: x86, ia64
959	Type: vcpu ioctl
960	Parameters: struct kvm_mp_state (out)
961	Returns: 0 on success; -1 on error
962	
963	struct kvm_mp_state {
964		__u32 mp_state;
965	};
966	
967	Returns the vcpu's current "multiprocessing state" (though also valid on
968	uniprocessor guests).
969	
970	Possible values are:
971	
972	 - KVM_MP_STATE_RUNNABLE:        the vcpu is currently running
973	 - KVM_MP_STATE_UNINITIALIZED:   the vcpu is an application processor (AP)
974	                                 which has not yet received an INIT signal
975	 - KVM_MP_STATE_INIT_RECEIVED:   the vcpu has received an INIT signal, and is
976	                                 now ready for a SIPI
977	 - KVM_MP_STATE_HALTED:          the vcpu has executed a HLT instruction and
978	                                 is waiting for an interrupt
979	 - KVM_MP_STATE_SIPI_RECEIVED:   the vcpu has just received a SIPI (vector
980	                                 accessible via KVM_GET_VCPU_EVENTS)
981	
982	This ioctl is only useful after KVM_CREATE_IRQCHIP.  Without an in-kernel
983	irqchip, the multiprocessing state must be maintained by userspace.
984	
985	
986	4.39 KVM_SET_MP_STATE
987	
988	Capability: KVM_CAP_MP_STATE
989	Architectures: x86, ia64
990	Type: vcpu ioctl
991	Parameters: struct kvm_mp_state (in)
992	Returns: 0 on success; -1 on error
993	
994	Sets the vcpu's current "multiprocessing state"; see KVM_GET_MP_STATE for
995	arguments.
996	
997	This ioctl is only useful after KVM_CREATE_IRQCHIP.  Without an in-kernel
998	irqchip, the multiprocessing state must be maintained by userspace.
999	
1000	
1001	4.40 KVM_SET_IDENTITY_MAP_ADDR
1002	
1003	Capability: KVM_CAP_SET_IDENTITY_MAP_ADDR
1004	Architectures: x86
1005	Type: vm ioctl
1006	Parameters: unsigned long identity (in)
1007	Returns: 0 on success, -1 on error
1008	
1009	This ioctl defines the physical address of a one-page region in the guest
1010	physical address space.  The region must be within the first 4GB of the
1011	guest physical address space and must not conflict with any memory slot
1012	or any mmio address.  The guest may malfunction if it accesses this memory
1013	region.
1014	
1015	This ioctl is required on Intel-based hosts.  This is needed on Intel hardware
1016	because of a quirk in the virtualization implementation (see the internals
1017	documentation when it pops into existence).
1018	
1019	
1020	4.41 KVM_SET_BOOT_CPU_ID
1021	
1022	Capability: KVM_CAP_SET_BOOT_CPU_ID
1023	Architectures: x86, ia64
1024	Type: vm ioctl
1025	Parameters: unsigned long vcpu_id
1026	Returns: 0 on success, -1 on error
1027	
1028	Define which vcpu is the Bootstrap Processor (BSP).  Values are the same
1029	as the vcpu id in KVM_CREATE_VCPU.  If this ioctl is not called, the default
1030	is vcpu 0.
1031	
1032	
1033	4.42 KVM_GET_XSAVE
1034	
1035	Capability: KVM_CAP_XSAVE
1036	Architectures: x86
1037	Type: vcpu ioctl
1038	Parameters: struct kvm_xsave (out)
1039	Returns: 0 on success, -1 on error
1040	
1041	struct kvm_xsave {
1042		__u32 region[1024];
1043	};
1044	
1045	This ioctl would copy current vcpu's xsave struct to the userspace.
1046	
1047	
1048	4.43 KVM_SET_XSAVE
1049	
1050	Capability: KVM_CAP_XSAVE
1051	Architectures: x86
1052	Type: vcpu ioctl
1053	Parameters: struct kvm_xsave (in)
1054	Returns: 0 on success, -1 on error
1055	
1056	struct kvm_xsave {
1057		__u32 region[1024];
1058	};
1059	
1060	This ioctl would copy userspace's xsave struct to the kernel.
1061	
1062	
1063	4.44 KVM_GET_XCRS
1064	
1065	Capability: KVM_CAP_XCRS
1066	Architectures: x86
1067	Type: vcpu ioctl
1068	Parameters: struct kvm_xcrs (out)
1069	Returns: 0 on success, -1 on error
1070	
1071	struct kvm_xcr {
1072		__u32 xcr;
1073		__u32 reserved;
1074		__u64 value;
1075	};
1076	
1077	struct kvm_xcrs {
1078		__u32 nr_xcrs;
1079		__u32 flags;
1080		struct kvm_xcr xcrs[KVM_MAX_XCRS];
1081		__u64 padding[16];
1082	};
1083	
1084	This ioctl would copy current vcpu's xcrs to the userspace.
1085	
1086	
1087	4.45 KVM_SET_XCRS
1088	
1089	Capability: KVM_CAP_XCRS
1090	Architectures: x86
1091	Type: vcpu ioctl
1092	Parameters: struct kvm_xcrs (in)
1093	Returns: 0 on success, -1 on error
1094	
1095	struct kvm_xcr {
1096		__u32 xcr;
1097		__u32 reserved;
1098		__u64 value;
1099	};
1100	
1101	struct kvm_xcrs {
1102		__u32 nr_xcrs;
1103		__u32 flags;
1104		struct kvm_xcr xcrs[KVM_MAX_XCRS];
1105		__u64 padding[16];
1106	};
1107	
1108	This ioctl would set vcpu's xcr to the value userspace specified.
1109	
1110	
1111	4.46 KVM_GET_SUPPORTED_CPUID
1112	
1113	Capability: KVM_CAP_EXT_CPUID
1114	Architectures: x86
1115	Type: system ioctl
1116	Parameters: struct kvm_cpuid2 (in/out)
1117	Returns: 0 on success, -1 on error
1118	
1119	struct kvm_cpuid2 {
1120		__u32 nent;
1121		__u32 padding;
1122		struct kvm_cpuid_entry2 entries[0];
1123	};
1124	
1125	#define KVM_CPUID_FLAG_SIGNIFCANT_INDEX		BIT(0)
1126	#define KVM_CPUID_FLAG_STATEFUL_FUNC		BIT(1)
1127	#define KVM_CPUID_FLAG_STATE_READ_NEXT		BIT(2)
1128	
1129	struct kvm_cpuid_entry2 {
1130		__u32 function;
1131		__u32 index;
1132		__u32 flags;
1133		__u32 eax;
1134		__u32 ebx;
1135		__u32 ecx;
1136		__u32 edx;
1137		__u32 padding[3];
1138	};
1139	
1140	This ioctl returns x86 cpuid features which are supported by both the hardware
1141	and kvm.  Userspace can use the information returned by this ioctl to
1142	construct cpuid information (for KVM_SET_CPUID2) that is consistent with
1143	hardware, kernel, and userspace capabilities, and with user requirements (for
1144	example, the user may wish to constrain cpuid to emulate older hardware,
1145	or for feature consistency across a cluster).
1146	
1147	Userspace invokes KVM_GET_SUPPORTED_CPUID by passing a kvm_cpuid2 structure
1148	with the 'nent' field indicating the number of entries in the variable-size
1149	array 'entries'.  If the number of entries is too low to describe the cpu
1150	capabilities, an error (E2BIG) is returned.  If the number is too high,
1151	the 'nent' field is adjusted and an error (ENOMEM) is returned.  If the
1152	number is just right, the 'nent' field is adjusted to the number of valid
1153	entries in the 'entries' array, which is then filled.
1154	
1155	The entries returned are the host cpuid as returned by the cpuid instruction,
1156	with unknown or unsupported features masked out.  Some features (for example,
1157	x2apic), may not be present in the host cpu, but are exposed by kvm if it can
1158	emulate them efficiently. The fields in each entry are defined as follows:
1159	
1160	  function: the eax value used to obtain the entry
1161	  index: the ecx value used to obtain the entry (for entries that are
1162	         affected by ecx)
1163	  flags: an OR of zero or more of the following:
1164	        KVM_CPUID_FLAG_SIGNIFCANT_INDEX:
1165	           if the index field is valid
1166	        KVM_CPUID_FLAG_STATEFUL_FUNC:
1167	           if cpuid for this function returns different values for successive
1168	           invocations; there will be several entries with the same function,
1169	           all with this flag set
1170	        KVM_CPUID_FLAG_STATE_READ_NEXT:
1171	           for KVM_CPUID_FLAG_STATEFUL_FUNC entries, set if this entry is
1172	           the first entry to be read by a cpu
1173	   eax, ebx, ecx, edx: the values returned by the cpuid instruction for
1174	         this function/index combination
1175	
1176	The TSC deadline timer feature (CPUID leaf 1, ecx[24]) is always returned
1177	as false, since the feature depends on KVM_CREATE_IRQCHIP for local APIC
1178	support.  Instead it is reported via
1179	
1180	  ioctl(KVM_CHECK_EXTENSION, KVM_CAP_TSC_DEADLINE_TIMER)
1181	
1182	if that returns true and you use KVM_CREATE_IRQCHIP, or if you emulate the
1183	feature in userspace, then you can enable the feature for KVM_SET_CPUID2.
1184	
1185	
1186	4.47 KVM_PPC_GET_PVINFO
1187	
1188	Capability: KVM_CAP_PPC_GET_PVINFO
1189	Architectures: ppc
1190	Type: vm ioctl
1191	Parameters: struct kvm_ppc_pvinfo (out)
1192	Returns: 0 on success, !0 on error
1193	
1194	struct kvm_ppc_pvinfo {
1195		__u32 flags;
1196		__u32 hcall[4];
1197		__u8  pad[108];
1198	};
1199	
1200	This ioctl fetches PV specific information that need to be passed to the guest
1201	using the device tree or other means from vm context.
1202	
1203	The hcall array defines 4 instructions that make up a hypercall.
1204	
1205	If any additional field gets added to this structure later on, a bit for that
1206	additional piece of information will be set in the flags bitmap.
1207	
1208	The flags bitmap is defined as:
1209	
1210	   /* the host supports the ePAPR idle hcall
1211	   #define KVM_PPC_PVINFO_FLAGS_EV_IDLE   (1<<0)
1212	
1213	4.48 KVM_ASSIGN_PCI_DEVICE
1214	
1215	Capability: KVM_CAP_DEVICE_ASSIGNMENT
1216	Architectures: x86 ia64
1217	Type: vm ioctl
1218	Parameters: struct kvm_assigned_pci_dev (in)
1219	Returns: 0 on success, -1 on error
1220	
1221	Assigns a host PCI device to the VM.
1222	
1223	struct kvm_assigned_pci_dev {
1224		__u32 assigned_dev_id;
1225		__u32 busnr;
1226		__u32 devfn;
1227		__u32 flags;
1228		__u32 segnr;
1229		union {
1230			__u32 reserved[11];
1231		};
1232	};
1233	
1234	The PCI device is specified by the triple segnr, busnr, and devfn.
1235	Identification in succeeding service requests is done via assigned_dev_id. The
1236	following flags are specified:
1237	
1238	/* Depends on KVM_CAP_IOMMU */
1239	#define KVM_DEV_ASSIGN_ENABLE_IOMMU	(1 << 0)
1240	/* The following two depend on KVM_CAP_PCI_2_3 */
1241	#define KVM_DEV_ASSIGN_PCI_2_3		(1 << 1)
1242	#define KVM_DEV_ASSIGN_MASK_INTX	(1 << 2)
1243	
1244	If KVM_DEV_ASSIGN_PCI_2_3 is set, the kernel will manage legacy INTx interrupts
1245	via the PCI-2.3-compliant device-level mask, thus enable IRQ sharing with other
1246	assigned devices or host devices. KVM_DEV_ASSIGN_MASK_INTX specifies the
1247	guest's view on the INTx mask, see KVM_ASSIGN_SET_INTX_MASK for details.
1248	
1249	The KVM_DEV_ASSIGN_ENABLE_IOMMU flag is a mandatory option to ensure
1250	isolation of the device.  Usages not specifying this flag are deprecated.
1251	
1252	Only PCI header type 0 devices with PCI BAR resources are supported by
1253	device assignment.  The user requesting this ioctl must have read/write
1254	access to the PCI sysfs resource files associated with the device.
1255	
1256	
1257	4.49 KVM_DEASSIGN_PCI_DEVICE
1258	
1259	Capability: KVM_CAP_DEVICE_DEASSIGNMENT
1260	Architectures: x86 ia64
1261	Type: vm ioctl
1262	Parameters: struct kvm_assigned_pci_dev (in)
1263	Returns: 0 on success, -1 on error
1264	
1265	Ends PCI device assignment, releasing all associated resources.
1266	
1267	See KVM_CAP_DEVICE_ASSIGNMENT for the data structure. Only assigned_dev_id is
1268	used in kvm_assigned_pci_dev to identify the device.
1269	
1270	
1271	4.50 KVM_ASSIGN_DEV_IRQ
1272	
1273	Capability: KVM_CAP_ASSIGN_DEV_IRQ
1274	Architectures: x86 ia64
1275	Type: vm ioctl
1276	Parameters: struct kvm_assigned_irq (in)
1277	Returns: 0 on success, -1 on error
1278	
1279	Assigns an IRQ to a passed-through device.
1280	
1281	struct kvm_assigned_irq {
1282		__u32 assigned_dev_id;
1283		__u32 host_irq; /* ignored (legacy field) */
1284		__u32 guest_irq;
1285		__u32 flags;
1286		union {
1287			__u32 reserved[12];
1288		};
1289	};
1290	
1291	The following flags are defined:
1292	
1293	#define KVM_DEV_IRQ_HOST_INTX    (1 << 0)
1294	#define KVM_DEV_IRQ_HOST_MSI     (1 << 1)
1295	#define KVM_DEV_IRQ_HOST_MSIX    (1 << 2)
1296	
1297	#define KVM_DEV_IRQ_GUEST_INTX   (1 << 8)
1298	#define KVM_DEV_IRQ_GUEST_MSI    (1 << 9)
1299	#define KVM_DEV_IRQ_GUEST_MSIX   (1 << 10)
1300	
1301	It is not valid to specify multiple types per host or guest IRQ. However, the
1302	IRQ type of host and guest can differ or can even be null.
1303	
1304	
1305	4.51 KVM_DEASSIGN_DEV_IRQ
1306	
1307	Capability: KVM_CAP_ASSIGN_DEV_IRQ
1308	Architectures: x86 ia64
1309	Type: vm ioctl
1310	Parameters: struct kvm_assigned_irq (in)
1311	Returns: 0 on success, -1 on error
1312	
1313	Ends an IRQ assignment to a passed-through device.
1314	
1315	See KVM_ASSIGN_DEV_IRQ for the data structure. The target device is specified
1316	by assigned_dev_id, flags must correspond to the IRQ type specified on
1317	KVM_ASSIGN_DEV_IRQ. Partial deassignment of host or guest IRQ is allowed.
1318	
1319	
1320	4.52 KVM_SET_GSI_ROUTING
1321	
1322	Capability: KVM_CAP_IRQ_ROUTING
1323	Architectures: x86 ia64
1324	Type: vm ioctl
1325	Parameters: struct kvm_irq_routing (in)
1326	Returns: 0 on success, -1 on error
1327	
1328	Sets the GSI routing table entries, overwriting any previously set entries.
1329	
1330	struct kvm_irq_routing {
1331		__u32 nr;
1332		__u32 flags;
1333		struct kvm_irq_routing_entry entries[0];
1334	};
1335	
1336	No flags are specified so far, the corresponding field must be set to zero.
1337	
1338	struct kvm_irq_routing_entry {
1339		__u32 gsi;
1340		__u32 type;
1341		__u32 flags;
1342		__u32 pad;
1343		union {
1344			struct kvm_irq_routing_irqchip irqchip;
1345			struct kvm_irq_routing_msi msi;
1346			__u32 pad[8];
1347		} u;
1348	};
1349	
1350	/* gsi routing entry types */
1351	#define KVM_IRQ_ROUTING_IRQCHIP 1
1352	#define KVM_IRQ_ROUTING_MSI 2
1353	
1354	No flags are specified so far, the corresponding field must be set to zero.
1355	
1356	struct kvm_irq_routing_irqchip {
1357		__u32 irqchip;
1358		__u32 pin;
1359	};
1360	
1361	struct kvm_irq_routing_msi {
1362		__u32 address_lo;
1363		__u32 address_hi;
1364		__u32 data;
1365		__u32 pad;
1366	};
1367	
1368	
1369	4.53 KVM_ASSIGN_SET_MSIX_NR
1370	
1371	Capability: KVM_CAP_DEVICE_MSIX
1372	Architectures: x86 ia64
1373	Type: vm ioctl
1374	Parameters: struct kvm_assigned_msix_nr (in)
1375	Returns: 0 on success, -1 on error
1376	
1377	Set the number of MSI-X interrupts for an assigned device. The number is
1378	reset again by terminating the MSI-X assignment of the device via
1379	KVM_DEASSIGN_DEV_IRQ. Calling this service more than once at any earlier
1380	point will fail.
1381	
1382	struct kvm_assigned_msix_nr {
1383		__u32 assigned_dev_id;
1384		__u16 entry_nr;
1385		__u16 padding;
1386	};
1387	
1388	#define KVM_MAX_MSIX_PER_DEV		256
1389	
1390	
1391	4.54 KVM_ASSIGN_SET_MSIX_ENTRY
1392	
1393	Capability: KVM_CAP_DEVICE_MSIX
1394	Architectures: x86 ia64
1395	Type: vm ioctl
1396	Parameters: struct kvm_assigned_msix_entry (in)
1397	Returns: 0 on success, -1 on error
1398	
1399	Specifies the routing of an MSI-X assigned device interrupt to a GSI. Setting
1400	the GSI vector to zero means disabling the interrupt.
1401	
1402	struct kvm_assigned_msix_entry {
1403		__u32 assigned_dev_id;
1404		__u32 gsi;
1405		__u16 entry; /* The index of entry in the MSI-X table */
1406		__u16 padding[3];
1407	};
1408	
1409	
1410	4.55 KVM_SET_TSC_KHZ
1411	
1412	Capability: KVM_CAP_TSC_CONTROL
1413	Architectures: x86
1414	Type: vcpu ioctl
1415	Parameters: virtual tsc_khz
1416	Returns: 0 on success, -1 on error
1417	
1418	Specifies the tsc frequency for the virtual machine. The unit of the
1419	frequency is KHz.
1420	
1421	
1422	4.56 KVM_GET_TSC_KHZ
1423	
1424	Capability: KVM_CAP_GET_TSC_KHZ
1425	Architectures: x86
1426	Type: vcpu ioctl
1427	Parameters: none
1428	Returns: virtual tsc-khz on success, negative value on error
1429	
1430	Returns the tsc frequency of the guest. The unit of the return value is
1431	KHz. If the host has unstable tsc this ioctl returns -EIO instead as an
1432	error.
1433	
1434	
1435	4.57 KVM_GET_LAPIC
1436	
1437	Capability: KVM_CAP_IRQCHIP
1438	Architectures: x86
1439	Type: vcpu ioctl
1440	Parameters: struct kvm_lapic_state (out)
1441	Returns: 0 on success, -1 on error
1442	
1443	#define KVM_APIC_REG_SIZE 0x400
1444	struct kvm_lapic_state {
1445		char regs[KVM_APIC_REG_SIZE];
1446	};
1447	
1448	Reads the Local APIC registers and copies them into the input argument.  The
1449	data format and layout are the same as documented in the architecture manual.
1450	
1451	
1452	4.58 KVM_SET_LAPIC
1453	
1454	Capability: KVM_CAP_IRQCHIP
1455	Architectures: x86
1456	Type: vcpu ioctl
1457	Parameters: struct kvm_lapic_state (in)
1458	Returns: 0 on success, -1 on error
1459	
1460	#define KVM_APIC_REG_SIZE 0x400
1461	struct kvm_lapic_state {
1462		char regs[KVM_APIC_REG_SIZE];
1463	};
1464	
1465	Copies the input argument into the the Local APIC registers.  The data format
1466	and layout are the same as documented in the architecture manual.
1467	
1468	
1469	4.59 KVM_IOEVENTFD
1470	
1471	Capability: KVM_CAP_IOEVENTFD
1472	Architectures: all
1473	Type: vm ioctl
1474	Parameters: struct kvm_ioeventfd (in)
1475	Returns: 0 on success, !0 on error
1476	
1477	This ioctl attaches or detaches an ioeventfd to a legal pio/mmio address
1478	within the guest.  A guest write in the registered address will signal the
1479	provided event instead of triggering an exit.
1480	
1481	struct kvm_ioeventfd {
1482		__u64 datamatch;
1483		__u64 addr;        /* legal pio/mmio address */
1484		__u32 len;         /* 1, 2, 4, or 8 bytes    */
1485		__s32 fd;
1486		__u32 flags;
1487		__u8  pad[36];
1488	};
1489	
1490	For the special case of virtio-ccw devices on s390, the ioevent is matched
1491	to a subchannel/virtqueue tuple instead.
1492	
1493	The following flags are defined:
1494	
1495	#define KVM_IOEVENTFD_FLAG_DATAMATCH (1 << kvm_ioeventfd_flag_nr_datamatch)
1496	#define KVM_IOEVENTFD_FLAG_PIO       (1 << kvm_ioeventfd_flag_nr_pio)
1497	#define KVM_IOEVENTFD_FLAG_DEASSIGN  (1 << kvm_ioeventfd_flag_nr_deassign)
1498	#define KVM_IOEVENTFD_FLAG_VIRTIO_CCW_NOTIFY \
1499		(1 << kvm_ioeventfd_flag_nr_virtio_ccw_notify)
1500	
1501	If datamatch flag is set, the event will be signaled only if the written value
1502	to the registered address is equal to datamatch in struct kvm_ioeventfd.
1503	
1504	For virtio-ccw devices, addr contains the subchannel id and datamatch the
1505	virtqueue index.
1506	
1507	
1508	4.60 KVM_DIRTY_TLB
1509	
1510	Capability: KVM_CAP_SW_TLB
1511	Architectures: ppc
1512	Type: vcpu ioctl
1513	Parameters: struct kvm_dirty_tlb (in)
1514	Returns: 0 on success, -1 on error
1515	
1516	struct kvm_dirty_tlb {
1517		__u64 bitmap;
1518		__u32 num_dirty;
1519	};
1520	
1521	This must be called whenever userspace has changed an entry in the shared
1522	TLB, prior to calling KVM_RUN on the associated vcpu.
1523	
1524	The "bitmap" field is the userspace address of an array.  This array
1525	consists of a number of bits, equal to the total number of TLB entries as
1526	determined by the last successful call to KVM_CONFIG_TLB, rounded up to the
1527	nearest multiple of 64.
1528	
1529	Each bit corresponds to one TLB entry, ordered the same as in the shared TLB
1530	array.
1531	
1532	The array is little-endian: the bit 0 is the least significant bit of the
1533	first byte, bit 8 is the least significant bit of the second byte, etc.
1534	This avoids any complications with differing word sizes.
1535	
1536	The "num_dirty" field is a performance hint for KVM to determine whether it
1537	should skip processing the bitmap and just invalidate everything.  It must
1538	be set to the number of set bits in the bitmap.
1539	
1540	
1541	4.61 KVM_ASSIGN_SET_INTX_MASK
1542	
1543	Capability: KVM_CAP_PCI_2_3
1544	Architectures: x86
1545	Type: vm ioctl
1546	Parameters: struct kvm_assigned_pci_dev (in)
1547	Returns: 0 on success, -1 on error
1548	
1549	Allows userspace to mask PCI INTx interrupts from the assigned device.  The
1550	kernel will not deliver INTx interrupts to the guest between setting and
1551	clearing of KVM_ASSIGN_SET_INTX_MASK via this interface.  This enables use of
1552	and emulation of PCI 2.3 INTx disable command register behavior.
1553	
1554	This may be used for both PCI 2.3 devices supporting INTx disable natively and
1555	older devices lacking this support. Userspace is responsible for emulating the
1556	read value of the INTx disable bit in the guest visible PCI command register.
1557	When modifying the INTx disable state, userspace should precede updating the
1558	physical device command register by calling this ioctl to inform the kernel of
1559	the new intended INTx mask state.
1560	
1561	Note that the kernel uses the device INTx disable bit to internally manage the
1562	device interrupt state for PCI 2.3 devices.  Reads of this register may
1563	therefore not match the expected value.  Writes should always use the guest
1564	intended INTx disable value rather than attempting to read-copy-update the
1565	current physical device state.  Races between user and kernel updates to the
1566	INTx disable bit are handled lazily in the kernel.  It's possible the device
1567	may generate unintended interrupts, but they will not be injected into the
1568	guest.
1569	
1570	See KVM_ASSIGN_DEV_IRQ for the data structure.  The target device is specified
1571	by assigned_dev_id.  In the flags field, only KVM_DEV_ASSIGN_MASK_INTX is
1572	evaluated.
1573	
1574	
1575	4.62 KVM_CREATE_SPAPR_TCE
1576	
1577	Capability: KVM_CAP_SPAPR_TCE
1578	Architectures: powerpc
1579	Type: vm ioctl
1580	Parameters: struct kvm_create_spapr_tce (in)
1581	Returns: file descriptor for manipulating the created TCE table
1582	
1583	This creates a virtual TCE (translation control entry) table, which
1584	is an IOMMU for PAPR-style virtual I/O.  It is used to translate
1585	logical addresses used in virtual I/O into guest physical addresses,
1586	and provides a scatter/gather capability for PAPR virtual I/O.
1587	
1588	/* for KVM_CAP_SPAPR_TCE */
1589	struct kvm_create_spapr_tce {
1590		__u64 liobn;
1591		__u32 window_size;
1592	};
1593	
1594	The liobn field gives the logical IO bus number for which to create a
1595	TCE table.  The window_size field specifies the size of the DMA window
1596	which this TCE table will translate - the table will contain one 64
1597	bit TCE entry for every 4kiB of the DMA window.
1598	
1599	When the guest issues an H_PUT_TCE hcall on a liobn for which a TCE
1600	table has been created using this ioctl(), the kernel will handle it
1601	in real mode, updating the TCE table.  H_PUT_TCE calls for other
1602	liobns will cause a vm exit and must be handled by userspace.
1603	
1604	The return value is a file descriptor which can be passed to mmap(2)
1605	to map the created TCE table into userspace.  This lets userspace read
1606	the entries written by kernel-handled H_PUT_TCE calls, and also lets
1607	userspace update the TCE table directly which is useful in some
1608	circumstances.
1609	
1610	
1611	4.63 KVM_ALLOCATE_RMA
1612	
1613	Capability: KVM_CAP_PPC_RMA
1614	Architectures: powerpc
1615	Type: vm ioctl
1616	Parameters: struct kvm_allocate_rma (out)
1617	Returns: file descriptor for mapping the allocated RMA
1618	
1619	This allocates a Real Mode Area (RMA) from the pool allocated at boot
1620	time by the kernel.  An RMA is a physically-contiguous, aligned region
1621	of memory used on older POWER processors to provide the memory which
1622	will be accessed by real-mode (MMU off) accesses in a KVM guest.
1623	POWER processors support a set of sizes for the RMA that usually
1624	includes 64MB, 128MB, 256MB and some larger powers of two.
1625	
1626	/* for KVM_ALLOCATE_RMA */
1627	struct kvm_allocate_rma {
1628		__u64 rma_size;
1629	};
1630	
1631	The return value is a file descriptor which can be passed to mmap(2)
1632	to map the allocated RMA into userspace.  The mapped area can then be
1633	passed to the KVM_SET_USER_MEMORY_REGION ioctl to establish it as the
1634	RMA for a virtual machine.  The size of the RMA in bytes (which is
1635	fixed at host kernel boot time) is returned in the rma_size field of
1636	the argument structure.
1637	
1638	The KVM_CAP_PPC_RMA capability is 1 or 2 if the KVM_ALLOCATE_RMA ioctl
1639	is supported; 2 if the processor requires all virtual machines to have
1640	an RMA, or 1 if the processor can use an RMA but doesn't require it,
1641	because it supports the Virtual RMA (VRMA) facility.
1642	
1643	
1644	4.64 KVM_NMI
1645	
1646	Capability: KVM_CAP_USER_NMI
1647	Architectures: x86
1648	Type: vcpu ioctl
1649	Parameters: none
1650	Returns: 0 on success, -1 on error
1651	
1652	Queues an NMI on the thread's vcpu.  Note this is well defined only
1653	when KVM_CREATE_IRQCHIP has not been called, since this is an interface
1654	between the virtual cpu core and virtual local APIC.  After KVM_CREATE_IRQCHIP
1655	has been called, this interface is completely emulated within the kernel.
1656	
1657	To use this to emulate the LINT1 input with KVM_CREATE_IRQCHIP, use the
1658	following algorithm:
1659	
1660	  - pause the vpcu
1661	  - read the local APIC's state (KVM_GET_LAPIC)
1662	  - check whether changing LINT1 will queue an NMI (see the LVT entry for LINT1)
1663	  - if so, issue KVM_NMI
1664	  - resume the vcpu
1665	
1666	Some guests configure the LINT1 NMI input to cause a panic, aiding in
1667	debugging.
1668	
1669	
1670	4.65 KVM_S390_UCAS_MAP
1671	
1672	Capability: KVM_CAP_S390_UCONTROL
1673	Architectures: s390
1674	Type: vcpu ioctl
1675	Parameters: struct kvm_s390_ucas_mapping (in)
1676	Returns: 0 in case of success
1677	
1678	The parameter is defined like this:
1679		struct kvm_s390_ucas_mapping {
1680			__u64 user_addr;
1681			__u64 vcpu_addr;
1682			__u64 length;
1683		};
1684	
1685	This ioctl maps the memory at "user_addr" with the length "length" to
1686	the vcpu's address space starting at "vcpu_addr". All parameters need to
1687	be aligned by 1 megabyte.
1688	
1689	
1690	4.66 KVM_S390_UCAS_UNMAP
1691	
1692	Capability: KVM_CAP_S390_UCONTROL
1693	Architectures: s390
1694	Type: vcpu ioctl
1695	Parameters: struct kvm_s390_ucas_mapping (in)
1696	Returns: 0 in case of success
1697	
1698	The parameter is defined like this:
1699		struct kvm_s390_ucas_mapping {
1700			__u64 user_addr;
1701			__u64 vcpu_addr;
1702			__u64 length;
1703		};
1704	
1705	This ioctl unmaps the memory in the vcpu's address space starting at
1706	"vcpu_addr" with the length "length". The field "user_addr" is ignored.
1707	All parameters need to be aligned by 1 megabyte.
1708	
1709	
1710	4.67 KVM_S390_VCPU_FAULT
1711	
1712	Capability: KVM_CAP_S390_UCONTROL
1713	Architectures: s390
1714	Type: vcpu ioctl
1715	Parameters: vcpu absolute address (in)
1716	Returns: 0 in case of success
1717	
1718	This call creates a page table entry on the virtual cpu's address space
1719	(for user controlled virtual machines) or the virtual machine's address
1720	space (for regular virtual machines). This only works for minor faults,
1721	thus it's recommended to access subject memory page via the user page
1722	table upfront. This is useful to handle validity intercepts for user
1723	controlled virtual machines to fault in the virtual cpu's lowcore pages
1724	prior to calling the KVM_RUN ioctl.
1725	
1726	
1727	4.68 KVM_SET_ONE_REG
1728	
1729	Capability: KVM_CAP_ONE_REG
1730	Architectures: all
1731	Type: vcpu ioctl
1732	Parameters: struct kvm_one_reg (in)
1733	Returns: 0 on success, negative value on failure
1734	
1735	struct kvm_one_reg {
1736	       __u64 id;
1737	       __u64 addr;
1738	};
1739	
1740	Using this ioctl, a single vcpu register can be set to a specific value
1741	defined by user space with the passed in struct kvm_one_reg, where id
1742	refers to the register identifier as described below and addr is a pointer
1743	to a variable with the respective size. There can be architecture agnostic
1744	and architecture specific registers. Each have their own range of operation
1745	and their own constants and width. To keep track of the implemented
1746	registers, find a list below:
1747	
1748	  Arch  |       Register        | Width (bits)
1749	        |                       |
1750	  PPC   | KVM_REG_PPC_HIOR      | 64
1751	  PPC   | KVM_REG_PPC_IAC1      | 64
1752	  PPC   | KVM_REG_PPC_IAC2      | 64
1753	  PPC   | KVM_REG_PPC_IAC3      | 64
1754	  PPC   | KVM_REG_PPC_IAC4      | 64
1755	  PPC   | KVM_REG_PPC_DAC1      | 64
1756	  PPC   | KVM_REG_PPC_DAC2      | 64
1757	  PPC   | KVM_REG_PPC_DABR      | 64
1758	  PPC   | KVM_REG_PPC_DSCR      | 64
1759	  PPC   | KVM_REG_PPC_PURR      | 64
1760	  PPC   | KVM_REG_PPC_SPURR     | 64
1761	  PPC   | KVM_REG_PPC_DAR       | 64
1762	  PPC   | KVM_REG_PPC_DSISR     | 32
1763	  PPC   | KVM_REG_PPC_AMR       | 64
1764	  PPC   | KVM_REG_PPC_UAMOR     | 64
1765	  PPC   | KVM_REG_PPC_MMCR0     | 64
1766	  PPC   | KVM_REG_PPC_MMCR1     | 64
1767	  PPC   | KVM_REG_PPC_MMCRA     | 64
1768	  PPC   | KVM_REG_PPC_PMC1      | 32
1769	  PPC   | KVM_REG_PPC_PMC2      | 32
1770	  PPC   | KVM_REG_PPC_PMC3      | 32
1771	  PPC   | KVM_REG_PPC_PMC4      | 32
1772	  PPC   | KVM_REG_PPC_PMC5      | 32
1773	  PPC   | KVM_REG_PPC_PMC6      | 32
1774	  PPC   | KVM_REG_PPC_PMC7      | 32
1775	  PPC   | KVM_REG_PPC_PMC8      | 32
1776	  PPC   | KVM_REG_PPC_FPR0      | 64
1777	          ...
1778	  PPC   | KVM_REG_PPC_FPR31     | 64
1779	  PPC   | KVM_REG_PPC_VR0       | 128
1780	          ...
1781	  PPC   | KVM_REG_PPC_VR31      | 128
1782	  PPC   | KVM_REG_PPC_VSR0      | 128
1783	          ...
1784	  PPC   | KVM_REG_PPC_VSR31     | 128
1785	  PPC   | KVM_REG_PPC_FPSCR     | 64
1786	  PPC   | KVM_REG_PPC_VSCR      | 32
1787	  PPC   | KVM_REG_PPC_VPA_ADDR  | 64
1788	  PPC   | KVM_REG_PPC_VPA_SLB   | 128
1789	  PPC   | KVM_REG_PPC_VPA_DTL   | 128
1790	  PPC   | KVM_REG_PPC_EPCR	| 32
1791	  PPC   | KVM_REG_PPC_EPR	| 32
1792	  PPC   | KVM_REG_PPC_TCR	| 32
1793	  PPC   | KVM_REG_PPC_TSR	| 32
1794	  PPC   | KVM_REG_PPC_OR_TSR	| 32
1795	  PPC   | KVM_REG_PPC_CLEAR_TSR	| 32
1796	  PPC   | KVM_REG_PPC_MAS0	| 32
1797	  PPC   | KVM_REG_PPC_MAS1	| 32
1798	  PPC   | KVM_REG_PPC_MAS2	| 64
1799	  PPC   | KVM_REG_PPC_MAS7_3	| 64
1800	  PPC   | KVM_REG_PPC_MAS4	| 32
1801	  PPC   | KVM_REG_PPC_MAS6	| 32
1802	  PPC   | KVM_REG_PPC_MMUCFG	| 32
1803	  PPC   | KVM_REG_PPC_TLB0CFG	| 32
1804	  PPC   | KVM_REG_PPC_TLB1CFG	| 32
1805	  PPC   | KVM_REG_PPC_TLB2CFG	| 32
1806	  PPC   | KVM_REG_PPC_TLB3CFG	| 32
1807	  PPC   | KVM_REG_PPC_TLB0PS	| 32
1808	  PPC   | KVM_REG_PPC_TLB1PS	| 32
1809	  PPC   | KVM_REG_PPC_TLB2PS	| 32
1810	  PPC   | KVM_REG_PPC_TLB3PS	| 32
1811	  PPC   | KVM_REG_PPC_EPTCFG	| 32
1812	  PPC   | KVM_REG_PPC_ICP_STATE | 64
1813	  PPC   | KVM_REG_PPC_TB_OFFSET	| 64
1814	  PPC   | KVM_REG_PPC_SPMC1	| 32
1815	  PPC   | KVM_REG_PPC_SPMC2	| 32
1816	  PPC   | KVM_REG_PPC_IAMR	| 64
1817	  PPC   | KVM_REG_PPC_TFHAR	| 64
1818	  PPC   | KVM_REG_PPC_TFIAR	| 64
1819	  PPC   | KVM_REG_PPC_TEXASR	| 64
1820	  PPC   | KVM_REG_PPC_FSCR	| 64
1821	  PPC   | KVM_REG_PPC_PSPB	| 32
1822	  PPC   | KVM_REG_PPC_EBBHR	| 64
1823	  PPC   | KVM_REG_PPC_EBBRR	| 64
1824	  PPC   | KVM_REG_PPC_BESCR	| 64
1825	  PPC   | KVM_REG_PPC_TAR	| 64
1826	  PPC   | KVM_REG_PPC_DPDES	| 64
1827	  PPC   | KVM_REG_PPC_DAWR	| 64
1828	  PPC   | KVM_REG_PPC_DAWRX	| 64
1829	  PPC   | KVM_REG_PPC_CIABR	| 64
1830	  PPC   | KVM_REG_PPC_IC	| 64
1831	  PPC   | KVM_REG_PPC_VTB	| 64
1832	  PPC   | KVM_REG_PPC_CSIGR	| 64
1833	  PPC   | KVM_REG_PPC_TACR	| 64
1834	  PPC   | KVM_REG_PPC_TCSCR	| 64
1835	  PPC   | KVM_REG_PPC_PID	| 64
1836	  PPC   | KVM_REG_PPC_ACOP	| 64
1837	  PPC   | KVM_REG_PPC_VRSAVE	| 32
1838	  PPC   | KVM_REG_PPC_LPCR	| 64
1839	  PPC   | KVM_REG_PPC_PPR	| 64
1840	  PPC   | KVM_REG_PPC_ARCH_COMPAT 32
1841	  PPC   | KVM_REG_PPC_TM_GPR0	| 64
1842	          ...
1843	  PPC   | KVM_REG_PPC_TM_GPR31	| 64
1844	  PPC   | KVM_REG_PPC_TM_VSR0	| 128
1845	          ...
1846	  PPC   | KVM_REG_PPC_TM_VSR63	| 128
1847	  PPC   | KVM_REG_PPC_TM_CR	| 64
1848	  PPC   | KVM_REG_PPC_TM_LR	| 64
1849	  PPC   | KVM_REG_PPC_TM_CTR	| 64
1850	  PPC   | KVM_REG_PPC_TM_FPSCR	| 64
1851	  PPC   | KVM_REG_PPC_TM_AMR	| 64
1852	  PPC   | KVM_REG_PPC_TM_PPR	| 64
1853	  PPC   | KVM_REG_PPC_TM_VRSAVE	| 64
1854	  PPC   | KVM_REG_PPC_TM_VSCR	| 32
1855	  PPC   | KVM_REG_PPC_TM_DSCR	| 64
1856	  PPC   | KVM_REG_PPC_TM_TAR	| 64
1857	
1858	ARM registers are mapped using the lower 32 bits.  The upper 16 of that
1859	is the register group type, or coprocessor number:
1860	
1861	ARM core registers have the following id bit patterns:
1862	  0x4020 0000 0010 <index into the kvm_regs struct:16>
1863	
1864	ARM 32-bit CP15 registers have the following id bit patterns:
1865	  0x4020 0000 000F <zero:1> <crn:4> <crm:4> <opc1:4> <opc2:3>
1866	
1867	ARM 64-bit CP15 registers have the following id bit patterns:
1868	  0x4030 0000 000F <zero:1> <zero:4> <crm:4> <opc1:4> <zero:3>
1869	
1870	ARM CCSIDR registers are demultiplexed by CSSELR value:
1871	  0x4020 0000 0011 00 <csselr:8>
1872	
1873	ARM 32-bit VFP control registers have the following id bit patterns:
1874	  0x4020 0000 0012 1 <regno:12>
1875	
1876	ARM 64-bit FP registers have the following id bit patterns:
1877	  0x4030 0000 0012 0 <regno:12>
1878	
1879	
1880	arm64 registers are mapped using the lower 32 bits. The upper 16 of
1881	that is the register group type, or coprocessor number:
1882	
1883	arm64 core/FP-SIMD registers have the following id bit patterns. Note
1884	that the size of the access is variable, as the kvm_regs structure
1885	contains elements ranging from 32 to 128 bits. The index is a 32bit
1886	value in the kvm_regs structure seen as a 32bit array.
1887	  0x60x0 0000 0010 <index into the kvm_regs struct:16>
1888	
1889	arm64 CCSIDR registers are demultiplexed by CSSELR value:
1890	  0x6020 0000 0011 00 <csselr:8>
1891	
1892	arm64 system registers have the following id bit patterns:
1893	  0x6030 0000 0013 <op0:2> <op1:3> <crn:4> <crm:4> <op2:3>
1894	
1895	4.69 KVM_GET_ONE_REG
1896	
1897	Capability: KVM_CAP_ONE_REG
1898	Architectures: all
1899	Type: vcpu ioctl
1900	Parameters: struct kvm_one_reg (in and out)
1901	Returns: 0 on success, negative value on failure
1902	
1903	This ioctl allows to receive the value of a single register implemented
1904	in a vcpu. The register to read is indicated by the "id" field of the
1905	kvm_one_reg struct passed in. On success, the register value can be found
1906	at the memory location pointed to by "addr".
1907	
1908	The list of registers accessible using this interface is identical to the
1909	list in 4.68.
1910	
1911	
1912	4.70 KVM_KVMCLOCK_CTRL
1913	
1914	Capability: KVM_CAP_KVMCLOCK_CTRL
1915	Architectures: Any that implement pvclocks (currently x86 only)
1916	Type: vcpu ioctl
1917	Parameters: None
1918	Returns: 0 on success, -1 on error
1919	
1920	This signals to the host kernel that the specified guest is being paused by
1921	userspace.  The host will set a flag in the pvclock structure that is checked
1922	from the soft lockup watchdog.  The flag is part of the pvclock structure that
1923	is shared between guest and host, specifically the second bit of the flags
1924	field of the pvclock_vcpu_time_info structure.  It will be set exclusively by
1925	the host and read/cleared exclusively by the guest.  The guest operation of
1926	checking and clearing the flag must an atomic operation so
1927	load-link/store-conditional, or equivalent must be used.  There are two cases
1928	where the guest will clear the flag: when the soft lockup watchdog timer resets
1929	itself or when a soft lockup is detected.  This ioctl can be called any time
1930	after pausing the vcpu, but before it is resumed.
1931	
1932	
1933	4.71 KVM_SIGNAL_MSI
1934	
1935	Capability: KVM_CAP_SIGNAL_MSI
1936	Architectures: x86
1937	Type: vm ioctl
1938	Parameters: struct kvm_msi (in)
1939	Returns: >0 on delivery, 0 if guest blocked the MSI, and -1 on error
1940	
1941	Directly inject a MSI message. Only valid with in-kernel irqchip that handles
1942	MSI messages.
1943	
1944	struct kvm_msi {
1945		__u32 address_lo;
1946		__u32 address_hi;
1947		__u32 data;
1948		__u32 flags;
1949		__u8  pad[16];
1950	};
1951	
1952	No flags are defined so far. The corresponding field must be 0.
1953	
1954	
1955	4.71 KVM_CREATE_PIT2
1956	
1957	Capability: KVM_CAP_PIT2
1958	Architectures: x86
1959	Type: vm ioctl
1960	Parameters: struct kvm_pit_config (in)
1961	Returns: 0 on success, -1 on error
1962	
1963	Creates an in-kernel device model for the i8254 PIT. This call is only valid
1964	after enabling in-kernel irqchip support via KVM_CREATE_IRQCHIP. The following
1965	parameters have to be passed:
1966	
1967	struct kvm_pit_config {
1968		__u32 flags;
1969		__u32 pad[15];
1970	};
1971	
1972	Valid flags are:
1973	
1974	#define KVM_PIT_SPEAKER_DUMMY     1 /* emulate speaker port stub */
1975	
1976	PIT timer interrupts may use a per-VM kernel thread for injection. If it
1977	exists, this thread will have a name of the following pattern:
1978	
1979	kvm-pit/<owner-process-pid>
1980	
1981	When running a guest with elevated priorities, the scheduling parameters of
1982	this thread may have to be adjusted accordingly.
1983	
1984	This IOCTL replaces the obsolete KVM_CREATE_PIT.
1985	
1986	
1987	4.72 KVM_GET_PIT2
1988	
1989	Capability: KVM_CAP_PIT_STATE2
1990	Architectures: x86
1991	Type: vm ioctl
1992	Parameters: struct kvm_pit_state2 (out)
1993	Returns: 0 on success, -1 on error
1994	
1995	Retrieves the state of the in-kernel PIT model. Only valid after
1996	KVM_CREATE_PIT2. The state is returned in the following structure:
1997	
1998	struct kvm_pit_state2 {
1999		struct kvm_pit_channel_state channels[3];
2000		__u32 flags;
2001		__u32 reserved[9];
2002	};
2003	
2004	Valid flags are:
2005	
2006	/* disable PIT in HPET legacy mode */
2007	#define KVM_PIT_FLAGS_HPET_LEGACY  0x00000001
2008	
2009	This IOCTL replaces the obsolete KVM_GET_PIT.
2010	
2011	
2012	4.73 KVM_SET_PIT2
2013	
2014	Capability: KVM_CAP_PIT_STATE2
2015	Architectures: x86
2016	Type: vm ioctl
2017	Parameters: struct kvm_pit_state2 (in)
2018	Returns: 0 on success, -1 on error
2019	
2020	Sets the state of the in-kernel PIT model. Only valid after KVM_CREATE_PIT2.
2021	See KVM_GET_PIT2 for details on struct kvm_pit_state2.
2022	
2023	This IOCTL replaces the obsolete KVM_SET_PIT.
2024	
2025	
2026	4.74 KVM_PPC_GET_SMMU_INFO
2027	
2028	Capability: KVM_CAP_PPC_GET_SMMU_INFO
2029	Architectures: powerpc
2030	Type: vm ioctl
2031	Parameters: None
2032	Returns: 0 on success, -1 on error
2033	
2034	This populates and returns a structure describing the features of
2035	the "Server" class MMU emulation supported by KVM.
2036	This can in turn be used by userspace to generate the appropriate
2037	device-tree properties for the guest operating system.
2038	
2039	The structure contains some global informations, followed by an
2040	array of supported segment page sizes:
2041	
2042	      struct kvm_ppc_smmu_info {
2043		     __u64 flags;
2044		     __u32 slb_size;
2045		     __u32 pad;
2046		     struct kvm_ppc_one_seg_page_size sps[KVM_PPC_PAGE_SIZES_MAX_SZ];
2047	      };
2048	
2049	The supported flags are:
2050	
2051	    - KVM_PPC_PAGE_SIZES_REAL:
2052	        When that flag is set, guest page sizes must "fit" the backing
2053	        store page sizes. When not set, any page size in the list can
2054	        be used regardless of how they are backed by userspace.
2055	
2056	    - KVM_PPC_1T_SEGMENTS
2057	        The emulated MMU supports 1T segments in addition to the
2058	        standard 256M ones.
2059	
2060	The "slb_size" field indicates how many SLB entries are supported
2061	
2062	The "sps" array contains 8 entries indicating the supported base
2063	page sizes for a segment in increasing order. Each entry is defined
2064	as follow:
2065	
2066	   struct kvm_ppc_one_seg_page_size {
2067		__u32 page_shift;	/* Base page shift of segment (or 0) */
2068		__u32 slb_enc;		/* SLB encoding for BookS */
2069		struct kvm_ppc_one_page_size enc[KVM_PPC_PAGE_SIZES_MAX_SZ];
2070	   };
2071	
2072	An entry with a "page_shift" of 0 is unused. Because the array is
2073	organized in increasing order, a lookup can stop when encoutering
2074	such an entry.
2075	
2076	The "slb_enc" field provides the encoding to use in the SLB for the
2077	page size. The bits are in positions such as the value can directly
2078	be OR'ed into the "vsid" argument of the slbmte instruction.
2079	
2080	The "enc" array is a list which for each of those segment base page
2081	size provides the list of supported actual page sizes (which can be
2082	only larger or equal to the base page size), along with the
2083	corresponding encoding in the hash PTE. Similarly, the array is
2084	8 entries sorted by increasing sizes and an entry with a "0" shift
2085	is an empty entry and a terminator:
2086	
2087	   struct kvm_ppc_one_page_size {
2088		__u32 page_shift;	/* Page shift (or 0) */
2089		__u32 pte_enc;		/* Encoding in the HPTE (>>12) */
2090	   };
2091	
2092	The "pte_enc" field provides a value that can OR'ed into the hash
2093	PTE's RPN field (ie, it needs to be shifted left by 12 to OR it
2094	into the hash PTE second double word).
2095	
2096	4.75 KVM_IRQFD
2097	
2098	Capability: KVM_CAP_IRQFD
2099	Architectures: x86
2100	Type: vm ioctl
2101	Parameters: struct kvm_irqfd (in)
2102	Returns: 0 on success, -1 on error
2103	
2104	Allows setting an eventfd to directly trigger a guest interrupt.
2105	kvm_irqfd.fd specifies the file descriptor to use as the eventfd and
2106	kvm_irqfd.gsi specifies the irqchip pin toggled by this event.  When
2107	an event is tiggered on the eventfd, an interrupt is injected into
2108	the guest using the specified gsi pin.  The irqfd is removed using
2109	the KVM_IRQFD_FLAG_DEASSIGN flag, specifying both kvm_irqfd.fd
2110	and kvm_irqfd.gsi.
2111	
2112	With KVM_CAP_IRQFD_RESAMPLE, KVM_IRQFD supports a de-assert and notify
2113	mechanism allowing emulation of level-triggered, irqfd-based
2114	interrupts.  When KVM_IRQFD_FLAG_RESAMPLE is set the user must pass an
2115	additional eventfd in the kvm_irqfd.resamplefd field.  When operating
2116	in resample mode, posting of an interrupt through kvm_irq.fd asserts
2117	the specified gsi in the irqchip.  When the irqchip is resampled, such
2118	as from an EOI, the gsi is de-asserted and the user is notifed via
2119	kvm_irqfd.resamplefd.  It is the user's responsibility to re-queue
2120	the interrupt if the device making use of it still requires service.
2121	Note that closing the resamplefd is not sufficient to disable the
2122	irqfd.  The KVM_IRQFD_FLAG_RESAMPLE is only necessary on assignment
2123	and need not be specified with KVM_IRQFD_FLAG_DEASSIGN.
2124	
2125	4.76 KVM_PPC_ALLOCATE_HTAB
2126	
2127	Capability: KVM_CAP_PPC_ALLOC_HTAB
2128	Architectures: powerpc
2129	Type: vm ioctl
2130	Parameters: Pointer to u32 containing hash table order (in/out)
2131	Returns: 0 on success, -1 on error
2132	
2133	This requests the host kernel to allocate an MMU hash table for a
2134	guest using the PAPR paravirtualization interface.  This only does
2135	anything if the kernel is configured to use the Book 3S HV style of
2136	virtualization.  Otherwise the capability doesn't exist and the ioctl
2137	returns an ENOTTY error.  The rest of this description assumes Book 3S
2138	HV.
2139	
2140	There must be no vcpus running when this ioctl is called; if there
2141	are, it will do nothing and return an EBUSY error.
2142	
2143	The parameter is a pointer to a 32-bit unsigned integer variable
2144	containing the order (log base 2) of the desired size of the hash
2145	table, which must be between 18 and 46.  On successful return from the
2146	ioctl, it will have been updated with the order of the hash table that
2147	was allocated.
2148	
2149	If no hash table has been allocated when any vcpu is asked to run
2150	(with the KVM_RUN ioctl), the host kernel will allocate a
2151	default-sized hash table (16 MB).
2152	
2153	If this ioctl is called when a hash table has already been allocated,
2154	the kernel will clear out the existing hash table (zero all HPTEs) and
2155	return the hash table order in the parameter.  (If the guest is using
2156	the virtualized real-mode area (VRMA) facility, the kernel will
2157	re-create the VMRA HPTEs on the next KVM_RUN of any vcpu.)
2158	
2159	4.77 KVM_S390_INTERRUPT
2160	
2161	Capability: basic
2162	Architectures: s390
2163	Type: vm ioctl, vcpu ioctl
2164	Parameters: struct kvm_s390_interrupt (in)
2165	Returns: 0 on success, -1 on error
2166	
2167	Allows to inject an interrupt to the guest. Interrupts can be floating
2168	(vm ioctl) or per cpu (vcpu ioctl), depending on the interrupt type.
2169	
2170	Interrupt parameters are passed via kvm_s390_interrupt:
2171	
2172	struct kvm_s390_interrupt {
2173		__u32 type;
2174		__u32 parm;
2175		__u64 parm64;
2176	};
2177	
2178	type can be one of the following:
2179	
2180	KVM_S390_SIGP_STOP (vcpu) - sigp restart
2181	KVM_S390_PROGRAM_INT (vcpu) - program check; code in parm
2182	KVM_S390_SIGP_SET_PREFIX (vcpu) - sigp set prefix; prefix address in parm
2183	KVM_S390_RESTART (vcpu) - restart
2184	KVM_S390_INT_VIRTIO (vm) - virtio external interrupt; external interrupt
2185				   parameters in parm and parm64
2186	KVM_S390_INT_SERVICE (vm) - sclp external interrupt; sclp parameter in parm
2187	KVM_S390_INT_EMERGENCY (vcpu) - sigp emergency; source cpu in parm
2188	KVM_S390_INT_EXTERNAL_CALL (vcpu) - sigp external call; source cpu in parm
2189	KVM_S390_INT_IO(ai,cssid,ssid,schid) (vm) - compound value to indicate an
2190	    I/O interrupt (ai - adapter interrupt; cssid,ssid,schid - subchannel);
2191	    I/O interruption parameters in parm (subchannel) and parm64 (intparm,
2192	    interruption subclass)
2193	KVM_S390_MCHK (vm, vcpu) - machine check interrupt; cr 14 bits in parm,
2194	                           machine check interrupt code in parm64 (note that
2195	                           machine checks needing further payload are not
2196	                           supported by this ioctl)
2197	
2198	Note that the vcpu ioctl is asynchronous to vcpu execution.
2199	
2200	4.78 KVM_PPC_GET_HTAB_FD
2201	
2202	Capability: KVM_CAP_PPC_HTAB_FD
2203	Architectures: powerpc
2204	Type: vm ioctl
2205	Parameters: Pointer to struct kvm_get_htab_fd (in)
2206	Returns: file descriptor number (>= 0) on success, -1 on error
2207	
2208	This returns a file descriptor that can be used either to read out the
2209	entries in the guest's hashed page table (HPT), or to write entries to
2210	initialize the HPT.  The returned fd can only be written to if the
2211	KVM_GET_HTAB_WRITE bit is set in the flags field of the argument, and
2212	can only be read if that bit is clear.  The argument struct looks like
2213	this:
2214	
2215	/* For KVM_PPC_GET_HTAB_FD */
2216	struct kvm_get_htab_fd {
2217		__u64	flags;
2218		__u64	start_index;
2219		__u64	reserved[2];
2220	};
2221	
2222	/* Values for kvm_get_htab_fd.flags */
2223	#define KVM_GET_HTAB_BOLTED_ONLY	((__u64)0x1)
2224	#define KVM_GET_HTAB_WRITE		((__u64)0x2)
2225	
2226	The `start_index' field gives the index in the HPT of the entry at
2227	which to start reading.  It is ignored when writing.
2228	
2229	Reads on the fd will initially supply information about all
2230	"interesting" HPT entries.  Interesting entries are those with the
2231	bolted bit set, if the KVM_GET_HTAB_BOLTED_ONLY bit is set, otherwise
2232	all entries.  When the end of the HPT is reached, the read() will
2233	return.  If read() is called again on the fd, it will start again from
2234	the beginning of the HPT, but will only return HPT entries that have
2235	changed since they were last read.
2236	
2237	Data read or written is structured as a header (8 bytes) followed by a
2238	series of valid HPT entries (16 bytes) each.  The header indicates how
2239	many valid HPT entries there are and how many invalid entries follow
2240	the valid entries.  The invalid entries are not represented explicitly
2241	in the stream.  The header format is:
2242	
2243	struct kvm_get_htab_header {
2244		__u32	index;
2245		__u16	n_valid;
2246		__u16	n_invalid;
2247	};
2248	
2249	Writes to the fd create HPT entries starting at the index given in the
2250	header; first `n_valid' valid entries with contents from the data
2251	written, then `n_invalid' invalid entries, invalidating any previously
2252	valid entries found.
2253	
2254	4.79 KVM_CREATE_DEVICE
2255	
2256	Capability: KVM_CAP_DEVICE_CTRL
2257	Type: vm ioctl
2258	Parameters: struct kvm_create_device (in/out)
2259	Returns: 0 on success, -1 on error
2260	Errors:
2261	  ENODEV: The device type is unknown or unsupported
2262	  EEXIST: Device already created, and this type of device may not
2263	          be instantiated multiple times
2264	
2265	  Other error conditions may be defined by individual device types or
2266	  have their standard meanings.
2267	
2268	Creates an emulated device in the kernel.  The file descriptor returned
2269	in fd can be used with KVM_SET/GET/HAS_DEVICE_ATTR.
2270	
2271	If the KVM_CREATE_DEVICE_TEST flag is set, only test whether the
2272	device type is supported (not necessarily whether it can be created
2273	in the current vm).
2274	
2275	Individual devices should not define flags.  Attributes should be used
2276	for specifying any behavior that is not implied by the device type
2277	number.
2278	
2279	struct kvm_create_device {
2280		__u32	type;	/* in: KVM_DEV_TYPE_xxx */
2281		__u32	fd;	/* out: device handle */
2282		__u32	flags;	/* in: KVM_CREATE_DEVICE_xxx */
2283	};
2284	
2285	4.80 KVM_SET_DEVICE_ATTR/KVM_GET_DEVICE_ATTR
2286	
2287	Capability: KVM_CAP_DEVICE_CTRL
2288	Type: device ioctl
2289	Parameters: struct kvm_device_attr
2290	Returns: 0 on success, -1 on error
2291	Errors:
2292	  ENXIO:  The group or attribute is unknown/unsupported for this device
2293	  EPERM:  The attribute cannot (currently) be accessed this way
2294	          (e.g. read-only attribute, or attribute that only makes
2295	          sense when the device is in a different state)
2296	
2297	  Other error conditions may be defined by individual device types.
2298	
2299	Gets/sets a specified piece of device configuration and/or state.  The
2300	semantics are device-specific.  See individual device documentation in
2301	the "devices" directory.  As with ONE_REG, the size of the data
2302	transferred is defined by the particular attribute.
2303	
2304	struct kvm_device_attr {
2305		__u32	flags;		/* no flags currently defined */
2306		__u32	group;		/* device-defined */
2307		__u64	attr;		/* group-defined */
2308		__u64	addr;		/* userspace address of attr data */
2309	};
2310	
2311	4.81 KVM_HAS_DEVICE_ATTR
2312	
2313	Capability: KVM_CAP_DEVICE_CTRL
2314	Type: device ioctl
2315	Parameters: struct kvm_device_attr
2316	Returns: 0 on success, -1 on error
2317	Errors:
2318	  ENXIO:  The group or attribute is unknown/unsupported for this device
2319	
2320	Tests whether a device supports a particular attribute.  A successful
2321	return indicates the attribute is implemented.  It does not necessarily
2322	indicate that the attribute can be read or written in the device's
2323	current state.  "addr" is ignored.
2324	
2325	4.82 KVM_ARM_VCPU_INIT
2326	
2327	Capability: basic
2328	Architectures: arm, arm64
2329	Type: vcpu ioctl
2330	Parameters: struct struct kvm_vcpu_init (in)
2331	Returns: 0 on success; -1 on error
2332	Errors:
2333	  EINVAL:    the target is unknown, or the combination of features is invalid.
2334	  ENOENT:    a features bit specified is unknown.
2335	
2336	This tells KVM what type of CPU to present to the guest, and what
2337	optional features it should have.  This will cause a reset of the cpu
2338	registers to their initial values.  If this is not called, KVM_RUN will
2339	return ENOEXEC for that vcpu.
2340	
2341	Note that because some registers reflect machine topology, all vcpus
2342	should be created before this ioctl is invoked.
2343	
2344	Possible features:
2345		- KVM_ARM_VCPU_POWER_OFF: Starts the CPU in a power-off state.
2346		  Depends on KVM_CAP_ARM_PSCI.
2347		- KVM_ARM_VCPU_EL1_32BIT: Starts the CPU in a 32bit mode.
2348		  Depends on KVM_CAP_ARM_EL1_32BIT (arm64 only).
2349	
2350	
2351	4.83 KVM_ARM_PREFERRED_TARGET
2352	
2353	Capability: basic
2354	Architectures: arm, arm64
2355	Type: vm ioctl
2356	Parameters: struct struct kvm_vcpu_init (out)
2357	Returns: 0 on success; -1 on error
2358	Errors:
2359	  ENODEV:    no preferred target available for the host
2360	
2361	This queries KVM for preferred CPU target type which can be emulated
2362	by KVM on underlying host.
2363	
2364	The ioctl returns struct kvm_vcpu_init instance containing information
2365	about preferred CPU target type and recommended features for it.  The
2366	kvm_vcpu_init->features bitmap returned will have feature bits set if
2367	the preferred target recommends setting these features, but this is
2368	not mandatory.
2369	
2370	The information returned by this ioctl can be used to prepare an instance
2371	of struct kvm_vcpu_init for KVM_ARM_VCPU_INIT ioctl which will result in
2372	in VCPU matching underlying host.
2373	
2374	
2375	4.84 KVM_GET_REG_LIST
2376	
2377	Capability: basic
2378	Architectures: arm, arm64
2379	Type: vcpu ioctl
2380	Parameters: struct kvm_reg_list (in/out)
2381	Returns: 0 on success; -1 on error
2382	Errors:
2383	  E2BIG:     the reg index list is too big to fit in the array specified by
2384	             the user (the number required will be written into n).
2385	
2386	struct kvm_reg_list {
2387		__u64 n; /* number of registers in reg[] */
2388		__u64 reg[0];
2389	};
2390	
2391	This ioctl returns the guest registers that are supported for the
2392	KVM_GET_ONE_REG/KVM_SET_ONE_REG calls.
2393	
2394	4.85 KVM_ARM_SET_DEVICE_ADDR
2395	
2396	Capability: KVM_CAP_ARM_SET_DEVICE_ADDR
2397	Architectures: arm, arm64
2398	Type: vm ioctl
2399	Parameters: struct kvm_arm_device_address (in)
2400	Returns: 0 on success, -1 on error
2401	Errors:
2402	  ENODEV: The device id is unknown
2403	  ENXIO:  Device not supported on current system
2404	  EEXIST: Address already set
2405	  E2BIG:  Address outside guest physical address space
2406	  EBUSY:  Address overlaps with other device range
2407	
2408	struct kvm_arm_device_addr {
2409		__u64 id;
2410		__u64 addr;
2411	};
2412	
2413	Specify a device address in the guest's physical address space where guests
2414	can access emulated or directly exposed devices, which the host kernel needs
2415	to know about. The id field is an architecture specific identifier for a
2416	specific device.
2417	
2418	ARM/arm64 divides the id field into two parts, a device id and an
2419	address type id specific to the individual device.
2420	
2421	  bits:  | 63        ...       32 | 31    ...    16 | 15    ...    0 |
2422	  field: |        0x00000000      |     device id   |  addr type id  |
2423	
2424	ARM/arm64 currently only require this when using the in-kernel GIC
2425	support for the hardware VGIC features, using KVM_ARM_DEVICE_VGIC_V2
2426	as the device id.  When setting the base address for the guest's
2427	mapping of the VGIC virtual CPU and distributor interface, the ioctl
2428	must be called after calling KVM_CREATE_IRQCHIP, but before calling
2429	KVM_RUN on any of the VCPUs.  Calling this ioctl twice for any of the
2430	base addresses will return -EEXIST.
2431	
2432	4.86 KVM_PPC_RTAS_DEFINE_TOKEN
2433	
2434	Capability: KVM_CAP_PPC_RTAS
2435	Architectures: ppc
2436	Type: vm ioctl
2437	Parameters: struct kvm_rtas_token_args
2438	Returns: 0 on success, -1 on error
2439	
2440	Defines a token value for a RTAS (Run Time Abstraction Services)
2441	service in order to allow it to be handled in the kernel.  The
2442	argument struct gives the name of the service, which must be the name
2443	of a service that has a kernel-side implementation.  If the token
2444	value is non-zero, it will be associated with that service, and
2445	subsequent RTAS calls by the guest specifying that token will be
2446	handled by the kernel.  If the token value is 0, then any token
2447	associated with the service will be forgotten, and subsequent RTAS
2448	calls by the guest for that service will be passed to userspace to be
2449	handled.
2450	
2451	
2452	5. The kvm_run structure
2453	------------------------
2454	
2455	Application code obtains a pointer to the kvm_run structure by
2456	mmap()ing a vcpu fd.  From that point, application code can control
2457	execution by changing fields in kvm_run prior to calling the KVM_RUN
2458	ioctl, and obtain information about the reason KVM_RUN returned by
2459	looking up structure members.
2460	
2461	struct kvm_run {
2462		/* in */
2463		__u8 request_interrupt_window;
2464	
2465	Request that KVM_RUN return when it becomes possible to inject external
2466	interrupts into the guest.  Useful in conjunction with KVM_INTERRUPT.
2467	
2468		__u8 padding1[7];
2469	
2470		/* out */
2471		__u32 exit_reason;
2472	
2473	When KVM_RUN has returned successfully (return value 0), this informs
2474	application code why KVM_RUN has returned.  Allowable values for this
2475	field are detailed below.
2476	
2477		__u8 ready_for_interrupt_injection;
2478	
2479	If request_interrupt_window has been specified, this field indicates
2480	an interrupt can be injected now with KVM_INTERRUPT.
2481	
2482		__u8 if_flag;
2483	
2484	The value of the current interrupt flag.  Only valid if in-kernel
2485	local APIC is not used.
2486	
2487		__u8 padding2[2];
2488	
2489		/* in (pre_kvm_run), out (post_kvm_run) */
2490		__u64 cr8;
2491	
2492	The value of the cr8 register.  Only valid if in-kernel local APIC is
2493	not used.  Both input and output.
2494	
2495		__u64 apic_base;
2496	
2497	The value of the APIC BASE msr.  Only valid if in-kernel local
2498	APIC is not used.  Both input and output.
2499	
2500		union {
2501			/* KVM_EXIT_UNKNOWN */
2502			struct {
2503				__u64 hardware_exit_reason;
2504			} hw;
2505	
2506	If exit_reason is KVM_EXIT_UNKNOWN, the vcpu has exited due to unknown
2507	reasons.  Further architecture-specific information is available in
2508	hardware_exit_reason.
2509	
2510			/* KVM_EXIT_FAIL_ENTRY */
2511			struct {
2512				__u64 hardware_entry_failure_reason;
2513			} fail_entry;
2514	
2515	If exit_reason is KVM_EXIT_FAIL_ENTRY, the vcpu could not be run due
2516	to unknown reasons.  Further architecture-specific information is
2517	available in hardware_entry_failure_reason.
2518	
2519			/* KVM_EXIT_EXCEPTION */
2520			struct {
2521				__u32 exception;
2522				__u32 error_code;
2523			} ex;
2524	
2525	Unused.
2526	
2527			/* KVM_EXIT_IO */
2528			struct {
2529	#define KVM_EXIT_IO_IN  0
2530	#define KVM_EXIT_IO_OUT 1
2531				__u8 direction;
2532				__u8 size; /* bytes */
2533				__u16 port;
2534				__u32 count;
2535				__u64 data_offset; /* relative to kvm_run start */
2536			} io;
2537	
2538	If exit_reason is KVM_EXIT_IO, then the vcpu has
2539	executed a port I/O instruction which could not be satisfied by kvm.
2540	data_offset describes where the data is located (KVM_EXIT_IO_OUT) or
2541	where kvm expects application code to place the data for the next
2542	KVM_RUN invocation (KVM_EXIT_IO_IN).  Data format is a packed array.
2543	
2544			struct {
2545				struct kvm_debug_exit_arch arch;
2546			} debug;
2547	
2548	Unused.
2549	
2550			/* KVM_EXIT_MMIO */
2551			struct {
2552				__u64 phys_addr;
2553				__u8  data[8];
2554				__u32 len;
2555				__u8  is_write;
2556			} mmio;
2557	
2558	If exit_reason is KVM_EXIT_MMIO, then the vcpu has
2559	executed a memory-mapped I/O instruction which could not be satisfied
2560	by kvm.  The 'data' member contains the written data if 'is_write' is
2561	true, and should be filled by application code otherwise.
2562	
2563	NOTE: For KVM_EXIT_IO, KVM_EXIT_MMIO, KVM_EXIT_OSI, KVM_EXIT_DCR,
2564	      KVM_EXIT_PAPR and KVM_EXIT_EPR the corresponding
2565	operations are complete (and guest state is consistent) only after userspace
2566	has re-entered the kernel with KVM_RUN.  The kernel side will first finish
2567	incomplete operations and then check for pending signals.  Userspace
2568	can re-enter the guest with an unmasked signal pending to complete
2569	pending operations.
2570	
2571			/* KVM_EXIT_HYPERCALL */
2572			struct {
2573				__u64 nr;
2574				__u64 args[6];
2575				__u64 ret;
2576				__u32 longmode;
2577				__u32 pad;
2578			} hypercall;
2579	
2580	Unused.  This was once used for 'hypercall to userspace'.  To implement
2581	such functionality, use KVM_EXIT_IO (x86) or KVM_EXIT_MMIO (all except s390).
2582	Note KVM_EXIT_IO is significantly faster than KVM_EXIT_MMIO.
2583	
2584			/* KVM_EXIT_TPR_ACCESS */
2585			struct {
2586				__u64 rip;
2587				__u32 is_write;
2588				__u32 pad;
2589			} tpr_access;
2590	
2591	To be documented (KVM_TPR_ACCESS_REPORTING).
2592	
2593			/* KVM_EXIT_S390_SIEIC */
2594			struct {
2595				__u8 icptcode;
2596				__u64 mask; /* psw upper half */
2597				__u64 addr; /* psw lower half */
2598				__u16 ipa;
2599				__u32 ipb;
2600			} s390_sieic;
2601	
2602	s390 specific.
2603	
2604			/* KVM_EXIT_S390_RESET */
2605	#define KVM_S390_RESET_POR       1
2606	#define KVM_S390_RESET_CLEAR     2
2607	#define KVM_S390_RESET_SUBSYSTEM 4
2608	#define KVM_S390_RESET_CPU_INIT  8
2609	#define KVM_S390_RESET_IPL       16
2610			__u64 s390_reset_flags;
2611	
2612	s390 specific.
2613	
2614			/* KVM_EXIT_S390_UCONTROL */
2615			struct {
2616				__u64 trans_exc_code;
2617				__u32 pgm_code;
2618			} s390_ucontrol;
2619	
2620	s390 specific. A page fault has occurred for a user controlled virtual
2621	machine (KVM_VM_S390_UNCONTROL) on it's host page table that cannot be
2622	resolved by the kernel.
2623	The program code and the translation exception code that were placed
2624	in the cpu's lowcore are presented here as defined by the z Architecture
2625	Principles of Operation Book in the Chapter for Dynamic Address Translation
2626	(DAT)
2627	
2628			/* KVM_EXIT_DCR */
2629			struct {
2630				__u32 dcrn;
2631				__u32 data;
2632				__u8  is_write;
2633			} dcr;
2634	
2635	powerpc specific.
2636	
2637			/* KVM_EXIT_OSI */
2638			struct {
2639				__u64 gprs[32];
2640			} osi;
2641	
2642	MOL uses a special hypercall interface it calls 'OSI'. To enable it, we catch
2643	hypercalls and exit with this exit struct that contains all the guest gprs.
2644	
2645	If exit_reason is KVM_EXIT_OSI, then the vcpu has triggered such a hypercall.
2646	Userspace can now handle the hypercall and when it's done modify the gprs as
2647	necessary. Upon guest entry all guest GPRs will then be replaced by the values
2648	in this struct.
2649	
2650			/* KVM_EXIT_PAPR_HCALL */
2651			struct {
2652				__u64 nr;
2653				__u64 ret;
2654				__u64 args[9];
2655			} papr_hcall;
2656	
2657	This is used on 64-bit PowerPC when emulating a pSeries partition,
2658	e.g. with the 'pseries' machine type in qemu.  It occurs when the
2659	guest does a hypercall using the 'sc 1' instruction.  The 'nr' field
2660	contains the hypercall number (from the guest R3), and 'args' contains
2661	the arguments (from the guest R4 - R12).  Userspace should put the
2662	return code in 'ret' and any extra returned values in args[].
2663	The possible hypercalls are defined in the Power Architecture Platform
2664	Requirements (PAPR) document available from www.power.org (free
2665	developer registration required to access it).
2666	
2667			/* KVM_EXIT_S390_TSCH */
2668			struct {
2669				__u16 subchannel_id;
2670				__u16 subchannel_nr;
2671				__u32 io_int_parm;
2672				__u32 io_int_word;
2673				__u32 ipb;
2674				__u8 dequeued;
2675			} s390_tsch;
2676	
2677	s390 specific. This exit occurs when KVM_CAP_S390_CSS_SUPPORT has been enabled
2678	and TEST SUBCHANNEL was intercepted. If dequeued is set, a pending I/O
2679	interrupt for the target subchannel has been dequeued and subchannel_id,
2680	subchannel_nr, io_int_parm and io_int_word contain the parameters for that
2681	interrupt. ipb is needed for instruction parameter decoding.
2682	
2683			/* KVM_EXIT_EPR */
2684			struct {
2685				__u32 epr;
2686			} epr;
2687	
2688	On FSL BookE PowerPC chips, the interrupt controller has a fast patch
2689	interrupt acknowledge path to the core. When the core successfully
2690	delivers an interrupt, it automatically populates the EPR register with
2691	the interrupt vector number and acknowledges the interrupt inside
2692	the interrupt controller.
2693	
2694	In case the interrupt controller lives in user space, we need to do
2695	the interrupt acknowledge cycle through it to fetch the next to be
2696	delivered interrupt vector using this exit.
2697	
2698	It gets triggered whenever both KVM_CAP_PPC_EPR are enabled and an
2699	external interrupt has just been delivered into the guest. User space
2700	should put the acknowledged interrupt vector into the 'epr' field.
2701	
2702			/* Fix the size of the union. */
2703			char padding[256];
2704		};
2705	
2706		/*
2707		 * shared registers between kvm and userspace.
2708		 * kvm_valid_regs specifies the register classes set by the host
2709		 * kvm_dirty_regs specified the register classes dirtied by userspace
2710		 * struct kvm_sync_regs is architecture specific, as well as the
2711		 * bits for kvm_valid_regs and kvm_dirty_regs
2712		 */
2713		__u64 kvm_valid_regs;
2714		__u64 kvm_dirty_regs;
2715		union {
2716			struct kvm_sync_regs regs;
2717			char padding[1024];
2718		} s;
2719	
2720	If KVM_CAP_SYNC_REGS is defined, these fields allow userspace to access
2721	certain guest registers without having to call SET/GET_*REGS. Thus we can
2722	avoid some system call overhead if userspace has to handle the exit.
2723	Userspace can query the validity of the structure by checking
2724	kvm_valid_regs for specific bits. These bits are architecture specific
2725	and usually define the validity of a groups of registers. (e.g. one bit
2726	 for general purpose registers)
2727	
2728	};
2729	
2730	
2731	4.81 KVM_GET_EMULATED_CPUID
2732	
2733	Capability: KVM_CAP_EXT_EMUL_CPUID
2734	Architectures: x86
2735	Type: system ioctl
2736	Parameters: struct kvm_cpuid2 (in/out)
2737	Returns: 0 on success, -1 on error
2738	
2739	struct kvm_cpuid2 {
2740		__u32 nent;
2741		__u32 flags;
2742		struct kvm_cpuid_entry2 entries[0];
2743	};
2744	
2745	The member 'flags' is used for passing flags from userspace.
2746	
2747	#define KVM_CPUID_FLAG_SIGNIFCANT_INDEX		BIT(0)
2748	#define KVM_CPUID_FLAG_STATEFUL_FUNC		BIT(1)
2749	#define KVM_CPUID_FLAG_STATE_READ_NEXT		BIT(2)
2750	
2751	struct kvm_cpuid_entry2 {
2752		__u32 function;
2753		__u32 index;
2754		__u32 flags;
2755		__u32 eax;
2756		__u32 ebx;
2757		__u32 ecx;
2758		__u32 edx;
2759		__u32 padding[3];
2760	};
2761	
2762	This ioctl returns x86 cpuid features which are emulated by
2763	kvm.Userspace can use the information returned by this ioctl to query
2764	which features are emulated by kvm instead of being present natively.
2765	
2766	Userspace invokes KVM_GET_EMULATED_CPUID by passing a kvm_cpuid2
2767	structure with the 'nent' field indicating the number of entries in
2768	the variable-size array 'entries'. If the number of entries is too low
2769	to describe the cpu capabilities, an error (E2BIG) is returned. If the
2770	number is too high, the 'nent' field is adjusted and an error (ENOMEM)
2771	is returned. If the number is just right, the 'nent' field is adjusted
2772	to the number of valid entries in the 'entries' array, which is then
2773	filled.
2774	
2775	The entries returned are the set CPUID bits of the respective features
2776	which kvm emulates, as returned by the CPUID instruction, with unknown
2777	or unsupported feature bits cleared.
2778	
2779	Features like x2apic, for example, may not be present in the host cpu
2780	but are exposed by kvm in KVM_GET_SUPPORTED_CPUID because they can be
2781	emulated efficiently and thus not included here.
2782	
2783	The fields in each entry are defined as follows:
2784	
2785	  function: the eax value used to obtain the entry
2786	  index: the ecx value used to obtain the entry (for entries that are
2787	         affected by ecx)
2788	  flags: an OR of zero or more of the following:
2789	        KVM_CPUID_FLAG_SIGNIFCANT_INDEX:
2790	           if the index field is valid
2791	        KVM_CPUID_FLAG_STATEFUL_FUNC:
2792	           if cpuid for this function returns different values for successive
2793	           invocations; there will be several entries with the same function,
2794	           all with this flag set
2795	        KVM_CPUID_FLAG_STATE_READ_NEXT:
2796	           for KVM_CPUID_FLAG_STATEFUL_FUNC entries, set if this entry is
2797	           the first entry to be read by a cpu
2798	   eax, ebx, ecx, edx: the values returned by the cpuid instruction for
2799	         this function/index combination
2800	
2801	
2802	6. Capabilities that can be enabled
2803	-----------------------------------
2804	
2805	There are certain capabilities that change the behavior of the virtual CPU when
2806	enabled. To enable them, please see section 4.37. Below you can find a list of
2807	capabilities and what their effect on the vCPU is when enabling them.
2808	
2809	The following information is provided along with the description:
2810	
2811	  Architectures: which instruction set architectures provide this ioctl.
2812	      x86 includes both i386 and x86_64.
2813	
2814	  Parameters: what parameters are accepted by the capability.
2815	
2816	  Returns: the return value.  General error numbers (EBADF, ENOMEM, EINVAL)
2817	      are not detailed, but errors with specific meanings are.
2818	
2819	
2820	6.1 KVM_CAP_PPC_OSI
2821	
2822	Architectures: ppc
2823	Parameters: none
2824	Returns: 0 on success; -1 on error
2825	
2826	This capability enables interception of OSI hypercalls that otherwise would
2827	be treated as normal system calls to be injected into the guest. OSI hypercalls
2828	were invented by Mac-on-Linux to have a standardized communication mechanism
2829	between the guest and the host.
2830	
2831	When this capability is enabled, KVM_EXIT_OSI can occur.
2832	
2833	
2834	6.2 KVM_CAP_PPC_PAPR
2835	
2836	Architectures: ppc
2837	Parameters: none
2838	Returns: 0 on success; -1 on error
2839	
2840	This capability enables interception of PAPR hypercalls. PAPR hypercalls are
2841	done using the hypercall instruction "sc 1".
2842	
2843	It also sets the guest privilege level to "supervisor" mode. Usually the guest
2844	runs in "hypervisor" privilege mode with a few missing features.
2845	
2846	In addition to the above, it changes the semantics of SDR1. In this mode, the
2847	HTAB address part of SDR1 contains an HVA instead of a GPA, as PAPR keeps the
2848	HTAB invisible to the guest.
2849	
2850	When this capability is enabled, KVM_EXIT_PAPR_HCALL can occur.
2851	
2852	
2853	6.3 KVM_CAP_SW_TLB
2854	
2855	Architectures: ppc
2856	Parameters: args[0] is the address of a struct kvm_config_tlb
2857	Returns: 0 on success; -1 on error
2858	
2859	struct kvm_config_tlb {
2860		__u64 params;
2861		__u64 array;
2862		__u32 mmu_type;
2863		__u32 array_len;
2864	};
2865	
2866	Configures the virtual CPU's TLB array, establishing a shared memory area
2867	between userspace and KVM.  The "params" and "array" fields are userspace
2868	addresses of mmu-type-specific data structures.  The "array_len" field is an
2869	safety mechanism, and should be set to the size in bytes of the memory that
2870	userspace has reserved for the array.  It must be at least the size dictated
2871	by "mmu_type" and "params".
2872	
2873	While KVM_RUN is active, the shared region is under control of KVM.  Its
2874	contents are undefined, and any modification by userspace results in
2875	boundedly undefined behavior.
2876	
2877	On return from KVM_RUN, the shared region will reflect the current state of
2878	the guest's TLB.  If userspace makes any changes, it must call KVM_DIRTY_TLB
2879	to tell KVM which entries have been changed, prior to calling KVM_RUN again
2880	on this vcpu.
2881	
2882	For mmu types KVM_MMU_FSL_BOOKE_NOHV and KVM_MMU_FSL_BOOKE_HV:
2883	 - The "params" field is of type "struct kvm_book3e_206_tlb_params".
2884	 - The "array" field points to an array of type "struct
2885	   kvm_book3e_206_tlb_entry".
2886	 - The array consists of all entries in the first TLB, followed by all
2887	   entries in the second TLB.
2888	 - Within a TLB, entries are ordered first by increasing set number.  Within a
2889	   set, entries are ordered by way (increasing ESEL).
2890	 - The hash for determining set number in TLB0 is: (MAS2 >> 12) & (num_sets - 1)
2891	   where "num_sets" is the tlb_sizes[] value divided by the tlb_ways[] value.
2892	 - The tsize field of mas1 shall be set to 4K on TLB0, even though the
2893	   hardware ignores this value for TLB0.
2894	
2895	6.4 KVM_CAP_S390_CSS_SUPPORT
2896	
2897	Architectures: s390
2898	Parameters: none
2899	Returns: 0 on success; -1 on error
2900	
2901	This capability enables support for handling of channel I/O instructions.
2902	
2903	TEST PENDING INTERRUPTION and the interrupt portion of TEST SUBCHANNEL are
2904	handled in-kernel, while the other I/O instructions are passed to userspace.
2905	
2906	When this capability is enabled, KVM_EXIT_S390_TSCH will occur on TEST
2907	SUBCHANNEL intercepts.
2908	
2909	6.5 KVM_CAP_PPC_EPR
2910	
2911	Architectures: ppc
2912	Parameters: args[0] defines whether the proxy facility is active
2913	Returns: 0 on success; -1 on error
2914	
2915	This capability enables or disables the delivery of interrupts through the
2916	external proxy facility.
2917	
2918	When enabled (args[0] != 0), every time the guest gets an external interrupt
2919	delivered, it automatically exits into user space with a KVM_EXIT_EPR exit
2920	to receive the topmost interrupt vector.
2921	
2922	When disabled (args[0] == 0), behavior is as if this facility is unsupported.
2923	
2924	When this capability is enabled, KVM_EXIT_EPR can occur.
2925	
2926	6.6 KVM_CAP_IRQ_MPIC
2927	
2928	Architectures: ppc
2929	Parameters: args[0] is the MPIC device fd
2930	            args[1] is the MPIC CPU number for this vcpu
2931	
2932	This capability connects the vcpu to an in-kernel MPIC device.
2933	
2934	6.7 KVM_CAP_IRQ_XICS
2935	
2936	Architectures: ppc
2937	Parameters: args[0] is the XICS device fd
2938	            args[1] is the XICS CPU number (server ID) for this vcpu
2939	
2940	This capability connects the vcpu to an in-kernel XICS device.
Hide Line Numbers
About Kernel Documentation Linux Kernel Contact Linux Resources Linux Blog

Information is copyright its respective author. All material is available from the Linux Kernel Source distributed under a GPL License. This page is provided as a free service by mjmwired.net.