xref: /linux/arch/x86/kvm/hyperv.h (revision 3a2c4d55e32ad65efebdb6de44eef3bfa08bb49d)
1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3  * KVM Microsoft Hyper-V emulation
4  *
5  * derived from arch/x86/kvm/x86.c
6  *
7  * Copyright (C) 2006 Qumranet, Inc.
8  * Copyright (C) 2008 Qumranet, Inc.
9  * Copyright IBM Corporation, 2008
10  * Copyright 2010 Red Hat, Inc. and/or its affiliates.
11  * Copyright (C) 2015 Andrey Smetanin <asmetanin@virtuozzo.com>
12  *
13  * Authors:
14  *   Avi Kivity   <avi@qumranet.com>
15  *   Yaniv Kamay  <yaniv@qumranet.com>
16  *   Amit Shah    <amit.shah@qumranet.com>
17  *   Ben-Ami Yassour <benami@il.ibm.com>
18  *   Andrey Smetanin <asmetanin@virtuozzo.com>
19  */
20 
21 #ifndef __ARCH_X86_KVM_HYPERV_H__
22 #define __ARCH_X86_KVM_HYPERV_H__
23 
24 #include <linux/kvm_host.h>
25 
26 #include "regs.h"
27 
28 #ifdef CONFIG_KVM_HYPERV
29 
30 
31 /* Hyper-V SynIC timer */
32 struct kvm_vcpu_hv_stimer {
33 	struct hrtimer timer;
34 	int index;
35 	union hv_stimer_config config;
36 	u64 count;
37 	u64 exp_time;
38 	struct hv_message msg;
39 	bool msg_pending;
40 };
41 
42 /* Hyper-V synthetic interrupt controller (SynIC)*/
43 struct kvm_vcpu_hv_synic {
44 	u64 version;
45 	u64 control;
46 	u64 msg_page;
47 	u64 evt_page;
48 	atomic64_t sint[HV_SYNIC_SINT_COUNT];
49 	atomic_t sint_to_gsi[HV_SYNIC_SINT_COUNT];
50 	DECLARE_BITMAP(auto_eoi_bitmap, 256);
51 	DECLARE_BITMAP(vec_bitmap, 256);
52 	bool active;
53 	bool dont_zero_synic_pages;
54 };
55 
56 /* The maximum number of entries on the TLB flush fifo. */
57 #define KVM_HV_TLB_FLUSH_FIFO_SIZE (16)
58 /*
59  * Note: the following 'magic' entry is made up by KVM to avoid putting
60  * anything besides GVA on the TLB flush fifo. It is theoretically possible
61  * to observe a request to flush 4095 PFNs starting from 0xfffffffffffff000
62  * which will look identical. KVM's action to 'flush everything' instead of
63  * flushing these particular addresses is, however, fully legitimate as
64  * flushing more than requested is always OK.
65  */
66 #define KVM_HV_TLB_FLUSHALL_ENTRY  ((u64)-1)
67 
68 enum hv_tlb_flush_fifos {
69 	HV_L1_TLB_FLUSH_FIFO,
70 	HV_L2_TLB_FLUSH_FIFO,
71 	HV_NR_TLB_FLUSH_FIFOS,
72 };
73 
74 struct kvm_vcpu_hv_tlb_flush_fifo {
75 	spinlock_t write_lock;
76 	DECLARE_KFIFO(entries, u64, KVM_HV_TLB_FLUSH_FIFO_SIZE);
77 };
78 
79 /* Hyper-V per vcpu emulation context */
80 struct kvm_vcpu_hv {
81 	struct kvm_vcpu *vcpu;
82 	u32 vp_index;
83 	u64 hv_vapic;
84 	s64 runtime_offset;
85 	struct kvm_vcpu_hv_synic synic;
86 	struct kvm_hyperv_exit exit;
87 	struct kvm_vcpu_hv_stimer stimer[HV_SYNIC_STIMER_COUNT];
88 	DECLARE_BITMAP(stimer_pending_bitmap, HV_SYNIC_STIMER_COUNT);
89 	bool enforce_cpuid;
90 	struct {
91 		u32 features_eax; /* HYPERV_CPUID_FEATURES.EAX */
92 		u32 features_ebx; /* HYPERV_CPUID_FEATURES.EBX */
93 		u32 features_edx; /* HYPERV_CPUID_FEATURES.EDX */
94 		u32 enlightenments_eax; /* HYPERV_CPUID_ENLIGHTMENT_INFO.EAX */
95 		u32 enlightenments_ebx; /* HYPERV_CPUID_ENLIGHTMENT_INFO.EBX */
96 		u32 syndbg_cap_eax; /* HYPERV_CPUID_SYNDBG_PLATFORM_CAPABILITIES.EAX */
97 		u32 nested_eax; /* HYPERV_CPUID_NESTED_FEATURES.EAX */
98 		u32 nested_ebx; /* HYPERV_CPUID_NESTED_FEATURES.EBX */
99 	} cpuid_cache;
100 
101 	struct kvm_vcpu_hv_tlb_flush_fifo tlb_flush_fifo[HV_NR_TLB_FLUSH_FIFOS];
102 
103 	/*
104 	 * Preallocated buffers for handling hypercalls that pass sparse vCPU
105 	 * sets (for high vCPU counts, they're too large to comfortably fit on
106 	 * the stack).
107 	 */
108 	u64 sparse_banks[HV_MAX_SPARSE_VCPU_BANKS];
109 	DECLARE_BITMAP(vcpu_mask, KVM_MAX_VCPUS);
110 
111 	struct hv_vp_assist_page vp_assist_page;
112 
113 	struct {
114 		u64 pa_page_gpa;
115 		u64 vm_id;
116 		u32 vp_id;
117 	} nested;
118 };
119 
120 /* "Hv#1" signature */
121 #define HYPERV_CPUID_SIGNATURE_EAX 0x31237648
122 
123 /*
124  * The #defines related to the synthetic debugger are required by KDNet, but
125  * they are not documented in the Hyper-V TLFS because the synthetic debugger
126  * functionality has been deprecated and is subject to removal in future
127  * versions of Windows.
128  */
129 #define HYPERV_CPUID_SYNDBG_VENDOR_AND_MAX_FUNCTIONS	0x40000080
130 #define HYPERV_CPUID_SYNDBG_INTERFACE			0x40000081
131 #define HYPERV_CPUID_SYNDBG_PLATFORM_CAPABILITIES	0x40000082
132 
133 /*
134  * Hyper-V synthetic debugger platform capabilities
135  * These are HYPERV_CPUID_SYNDBG_PLATFORM_CAPABILITIES.EAX bits.
136  */
137 #define HV_X64_SYNDBG_CAP_ALLOW_KERNEL_DEBUGGING	BIT(1)
138 
139 /* Hyper-V Synthetic debug options MSR */
140 #define HV_X64_MSR_SYNDBG_CONTROL		0x400000F1
141 #define HV_X64_MSR_SYNDBG_STATUS		0x400000F2
142 #define HV_X64_MSR_SYNDBG_SEND_BUFFER		0x400000F3
143 #define HV_X64_MSR_SYNDBG_RECV_BUFFER		0x400000F4
144 #define HV_X64_MSR_SYNDBG_PENDING_BUFFER	0x400000F5
145 #define HV_X64_MSR_SYNDBG_OPTIONS		0x400000FF
146 
147 /* Hyper-V HV_X64_MSR_SYNDBG_OPTIONS bits */
148 #define HV_X64_SYNDBG_OPTION_USE_HCALLS		BIT(2)
149 
150 static inline struct kvm_hv *to_kvm_hv(struct kvm *kvm)
151 {
152 	return &kvm->arch.hyperv;
153 }
154 
155 static inline struct kvm_vcpu_hv *to_hv_vcpu_safe(struct kvm_vcpu *vcpu)
156 {
157 	/*
158 	 * Ensure the HyperV structure is fully initialized when accessing it
159 	 * without holding vcpu->mutex (or some other guarantee that KVM can't
160 	 * concurrently instantiate the structure).
161 	 *
162 	 * Pairs with the smp_store_release() in kvm_hv_vcpu_init().
163 	 */
164 	return smp_load_acquire(&vcpu->arch.hyperv);
165 }
166 
167 static inline struct kvm_vcpu_hv *to_hv_vcpu(struct kvm_vcpu *vcpu)
168 {
169 	kvm_lockdep_assert_vcpu_is_locked_or_unreachable(vcpu);
170 
171 	return vcpu->arch.hyperv;
172 }
173 
174 static inline struct kvm_vcpu_hv_synic *to_hv_synic(struct kvm_vcpu *vcpu)
175 {
176 	struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
177 
178 	return &hv_vcpu->synic;
179 }
180 
181 static inline struct kvm_vcpu *hv_synic_to_vcpu(struct kvm_vcpu_hv_synic *synic)
182 {
183 	struct kvm_vcpu_hv *hv_vcpu = container_of(synic, struct kvm_vcpu_hv, synic);
184 
185 	return hv_vcpu->vcpu;
186 }
187 
188 static inline struct kvm_hv_syndbg *to_hv_syndbg(struct kvm_vcpu *vcpu)
189 {
190 	return &vcpu->kvm->arch.hyperv.hv_syndbg;
191 }
192 
193 static inline u32 kvm_hv_get_vpindex(struct kvm_vcpu *vcpu)
194 {
195 	struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu_safe(vcpu);
196 
197 	return hv_vcpu ? hv_vcpu->vp_index : vcpu->vcpu_idx;
198 }
199 
200 int kvm_hv_set_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 data, bool host);
201 int kvm_hv_get_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata, bool host);
202 
203 static inline bool kvm_hv_hypercall_enabled(struct kvm_vcpu *vcpu)
204 {
205 	return vcpu->arch.hyperv_enabled && to_kvm_hv(vcpu->kvm)->hv_guest_os_id;
206 }
207 
208 int kvm_hv_hypercall(struct kvm_vcpu *vcpu);
209 
210 void kvm_hv_irq_routing_update(struct kvm *kvm);
211 int kvm_hv_synic_set_irq(struct kvm_kernel_irq_routing_entry *e, struct kvm *kvm,
212 			 int irq_source_id, int level, bool line_status);
213 void kvm_hv_synic_send_eoi(struct kvm_vcpu *vcpu, int vector);
214 int kvm_hv_activate_synic(struct kvm_vcpu *vcpu, bool dont_zero_synic_pages);
215 
216 static inline bool kvm_hv_synic_has_vector(struct kvm_vcpu *vcpu, int vector)
217 {
218 	return to_hv_vcpu(vcpu) && test_bit(vector, to_hv_synic(vcpu)->vec_bitmap);
219 }
220 
221 static inline bool kvm_hv_synic_auto_eoi_set(struct kvm_vcpu *vcpu, int vector)
222 {
223 	return to_hv_vcpu(vcpu) &&
224 	       test_bit(vector, to_hv_synic(vcpu)->auto_eoi_bitmap);
225 }
226 
227 void kvm_hv_vcpu_uninit(struct kvm_vcpu *vcpu);
228 
229 bool kvm_hv_assist_page_enabled(struct kvm_vcpu *vcpu);
230 int kvm_hv_get_assist_page(struct kvm_vcpu *vcpu);
231 
232 static inline struct kvm_vcpu_hv_stimer *to_hv_stimer(struct kvm_vcpu *vcpu,
233 						      int timer_index)
234 {
235 	return &to_hv_vcpu(vcpu)->stimer[timer_index];
236 }
237 
238 static inline struct kvm_vcpu *hv_stimer_to_vcpu(struct kvm_vcpu_hv_stimer *stimer)
239 {
240 	struct kvm_vcpu_hv *hv_vcpu;
241 
242 	hv_vcpu = container_of(stimer - stimer->index, struct kvm_vcpu_hv,
243 			       stimer[0]);
244 	return hv_vcpu->vcpu;
245 }
246 
247 static inline bool kvm_hv_has_stimer_pending(struct kvm_vcpu *vcpu)
248 {
249 	struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu_safe(vcpu);
250 
251 	if (!hv_vcpu)
252 		return false;
253 
254 	return !bitmap_empty(hv_vcpu->stimer_pending_bitmap,
255 			     HV_SYNIC_STIMER_COUNT);
256 }
257 
258 /*
259  * With HV_ACCESS_TSC_INVARIANT feature, invariant TSC (CPUID.80000007H:EDX[8])
260  * is only observed after HV_X64_MSR_TSC_INVARIANT_CONTROL was written to.
261  */
262 static inline bool kvm_hv_invtsc_suppressed(struct kvm_vcpu *vcpu)
263 {
264 	struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
265 
266 	/*
267 	 * If Hyper-V's invariant TSC control is not exposed to the guest,
268 	 * the invariant TSC CPUID flag is not suppressed, Windows guests were
269 	 * observed to be able to handle it correctly. Going forward, VMMs are
270 	 * encouraged to enable Hyper-V's invariant TSC control when invariant
271 	 * TSC CPUID flag is set to make KVM's behavior match genuine Hyper-V.
272 	 */
273 	if (!hv_vcpu ||
274 	    !(hv_vcpu->cpuid_cache.features_eax & HV_ACCESS_TSC_INVARIANT))
275 		return false;
276 
277 	/*
278 	 * If Hyper-V's invariant TSC control is exposed to the guest, KVM is
279 	 * responsible for suppressing the invariant TSC CPUID flag if the
280 	 * Hyper-V control is not enabled.
281 	 */
282 	return !(to_kvm_hv(vcpu->kvm)->hv_invtsc_control & HV_EXPOSE_INVARIANT_TSC);
283 }
284 
285 void kvm_hv_process_stimers(struct kvm_vcpu *vcpu);
286 
287 void kvm_hv_setup_tsc_page(struct kvm *kvm,
288 			   struct pvclock_vcpu_time_info *hv_clock);
289 void kvm_hv_request_tsc_page_update(struct kvm *kvm);
290 
291 void kvm_hv_xsaves_xsavec_maybe_warn(struct kvm_vcpu *vcpu);
292 
293 void kvm_hv_init_vm(struct kvm *kvm);
294 void kvm_hv_destroy_vm(struct kvm *kvm);
295 int kvm_hv_vcpu_init(struct kvm_vcpu *vcpu);
296 void kvm_hv_set_cpuid(struct kvm_vcpu *vcpu, bool hyperv_enabled);
297 int kvm_hv_set_enforce_cpuid(struct kvm_vcpu *vcpu, bool enforce);
298 int kvm_vm_ioctl_hv_eventfd(struct kvm *kvm, struct kvm_hyperv_eventfd *args);
299 int kvm_get_hv_cpuid(struct kvm_vcpu *vcpu, struct kvm_cpuid2 *cpuid,
300 		     struct kvm_cpuid_entry2 __user *entries);
301 
302 static inline struct kvm_vcpu_hv_tlb_flush_fifo *kvm_hv_get_tlb_flush_fifo(struct kvm_vcpu *vcpu,
303 									   bool is_guest_mode)
304 {
305 	struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu_safe(vcpu);
306 	int i = is_guest_mode ? HV_L2_TLB_FLUSH_FIFO :
307 				HV_L1_TLB_FLUSH_FIFO;
308 
309 	if (!hv_vcpu)
310 		return NULL;
311 
312 	return &hv_vcpu->tlb_flush_fifo[i];
313 }
314 
315 static inline void kvm_hv_vcpu_purge_flush_tlb(struct kvm_vcpu *vcpu)
316 {
317 	struct kvm_vcpu_hv_tlb_flush_fifo *tlb_flush_fifo;
318 
319 	if (!kvm_check_request(KVM_REQ_HV_TLB_FLUSH, vcpu))
320 		return;
321 
322 	tlb_flush_fifo = kvm_hv_get_tlb_flush_fifo(vcpu, is_guest_mode(vcpu));
323 	if (!tlb_flush_fifo)
324 		return;
325 
326 	kfifo_reset_out(&tlb_flush_fifo->entries);
327 }
328 
329 static inline bool guest_hv_cpuid_has_l2_tlb_flush(struct kvm_vcpu *vcpu)
330 {
331 	struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
332 
333 	return hv_vcpu &&
334 		(hv_vcpu->cpuid_cache.nested_eax & HV_X64_NESTED_DIRECT_FLUSH);
335 }
336 
337 static inline bool kvm_hv_is_tlb_flush_hcall(struct kvm_vcpu *vcpu)
338 {
339 	struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
340 	u16 code;
341 
342 	if (!hv_vcpu)
343 		return false;
344 
345 	code = is_64_bit_hypercall(vcpu) ? kvm_rcx_read_raw(vcpu) :
346 					   kvm_eax_read(vcpu);
347 
348 	return (code == HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE ||
349 		code == HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST ||
350 		code == HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE_EX ||
351 		code == HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST_EX);
352 }
353 
354 static inline int kvm_hv_verify_vp_assist(struct kvm_vcpu *vcpu)
355 {
356 	if (!to_hv_vcpu(vcpu))
357 		return 0;
358 
359 	if (!kvm_hv_assist_page_enabled(vcpu))
360 		return 0;
361 
362 	return kvm_hv_get_assist_page(vcpu);
363 }
364 
365 static inline void kvm_hv_nested_transtion_tlb_flush(struct kvm_vcpu *vcpu,
366 						     bool tdp_enabled)
367 {
368 	/*
369 	 * KVM_REQ_HV_TLB_FLUSH flushes entries from either L1's VP_ID or
370 	 * L2's VP_ID upon request from the guest. Make sure we check for
371 	 * pending entries in the right FIFO upon L1/L2 transition as these
372 	 * requests are put by other vCPUs asynchronously.
373 	 */
374 	if (to_hv_vcpu(vcpu) && tdp_enabled)
375 		kvm_make_request(KVM_REQ_HV_TLB_FLUSH, vcpu);
376 }
377 
378 int kvm_hv_vcpu_flush_tlb(struct kvm_vcpu *vcpu);
379 #else /* CONFIG_KVM_HYPERV */
380 static inline void kvm_hv_setup_tsc_page(struct kvm *kvm,
381 					 struct pvclock_vcpu_time_info *hv_clock) {}
382 static inline void kvm_hv_request_tsc_page_update(struct kvm *kvm) {}
383 static inline void kvm_hv_xsaves_xsavec_maybe_warn(struct kvm_vcpu *vcpu) {}
384 static inline void kvm_hv_init_vm(struct kvm *kvm) {}
385 static inline void kvm_hv_destroy_vm(struct kvm *kvm) {}
386 static inline int kvm_hv_vcpu_init(struct kvm_vcpu *vcpu)
387 {
388 	return 0;
389 }
390 static inline void kvm_hv_vcpu_uninit(struct kvm_vcpu *vcpu) {}
391 static inline bool kvm_hv_hypercall_enabled(struct kvm_vcpu *vcpu)
392 {
393 	return false;
394 }
395 static inline int kvm_hv_hypercall(struct kvm_vcpu *vcpu)
396 {
397 	return HV_STATUS_ACCESS_DENIED;
398 }
399 static inline void kvm_hv_vcpu_purge_flush_tlb(struct kvm_vcpu *vcpu) {}
400 static inline bool kvm_hv_synic_has_vector(struct kvm_vcpu *vcpu, int vector)
401 {
402 	return false;
403 }
404 static inline bool kvm_hv_synic_auto_eoi_set(struct kvm_vcpu *vcpu, int vector)
405 {
406 	return false;
407 }
408 static inline void kvm_hv_synic_send_eoi(struct kvm_vcpu *vcpu, int vector) {}
409 static inline bool kvm_hv_invtsc_suppressed(struct kvm_vcpu *vcpu)
410 {
411 	return false;
412 }
413 static inline void kvm_hv_set_cpuid(struct kvm_vcpu *vcpu, bool hyperv_enabled) {}
414 static inline bool kvm_hv_has_stimer_pending(struct kvm_vcpu *vcpu)
415 {
416 	return false;
417 }
418 static inline int kvm_hv_verify_vp_assist(struct kvm_vcpu *vcpu)
419 {
420 	return 0;
421 }
422 static inline u32 kvm_hv_get_vpindex(struct kvm_vcpu *vcpu)
423 {
424 	return vcpu->vcpu_idx;
425 }
426 static inline void kvm_hv_nested_transtion_tlb_flush(struct kvm_vcpu *vcpu, bool tdp_enabled) {}
427 #endif /* CONFIG_KVM_HYPERV */
428 
429 #endif /* __ARCH_X86_KVM_HYPERV_H__ */
430