xref: /linux/tools/testing/selftests/kvm/lib/x86/vmx.c (revision 9cb1944f6bf09ecebcc7609f35178b85aa26f165)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2018, Google LLC.
4  */
5 
6 #include <asm/msr-index.h>
7 
8 #include "test_util.h"
9 #include "kvm_util.h"
10 #include "processor.h"
11 #include "vmx.h"
12 
13 #define KVM_EPT_PAGE_TABLE_MIN_PADDR 0x1c0000
14 
15 #define EPTP_MT_SHIFT		0 /* EPTP memtype bits 2:0 */
16 #define EPTP_PWL_SHIFT		3 /* EPTP page walk length bits 5:3 */
17 #define EPTP_AD_ENABLED_SHIFT	6 /* EPTP AD enabled bit 6 */
18 
19 #define EPTP_WB			(X86_MEMTYPE_WB << EPTP_MT_SHIFT)
20 #define EPTP_PWL_4		(3ULL << EPTP_PWL_SHIFT) /* PWL is (levels - 1) */
21 #define EPTP_AD_ENABLED		(1ULL << EPTP_AD_ENABLED_SHIFT)
22 
23 bool enable_evmcs;
24 
25 struct hv_enlightened_vmcs *current_evmcs;
26 struct hv_vp_assist_page *current_vp_assist;
27 
28 int vcpu_enable_evmcs(struct kvm_vcpu *vcpu)
29 {
30 	uint16_t evmcs_ver;
31 
32 	vcpu_enable_cap(vcpu, KVM_CAP_HYPERV_ENLIGHTENED_VMCS,
33 			(unsigned long)&evmcs_ver);
34 
35 	/* KVM should return supported EVMCS version range */
36 	TEST_ASSERT(((evmcs_ver >> 8) >= (evmcs_ver & 0xff)) &&
37 		    (evmcs_ver & 0xff) > 0,
38 		    "Incorrect EVMCS version range: %x:%x",
39 		    evmcs_ver & 0xff, evmcs_ver >> 8);
40 
41 	return evmcs_ver;
42 }
43 
44 void vm_enable_ept(struct kvm_vm *vm)
45 {
46 	struct pte_masks pte_masks;
47 
48 	TEST_ASSERT(kvm_cpu_has_ept(), "KVM doesn't support nested EPT");
49 
50 	/*
51 	 * EPTs do not have 'present' or 'user' bits, instead bit 0 is the
52 	 * 'readable' bit.
53 	 */
54 	pte_masks = (struct pte_masks) {
55 		.present	=	0,
56 		.user		=	0,
57 		.readable	=	BIT_ULL(0),
58 		.writable	=	BIT_ULL(1),
59 		.executable	=	BIT_ULL(2),
60 		.huge		=	BIT_ULL(7),
61 		.accessed	=	BIT_ULL(8),
62 		.dirty		=	BIT_ULL(9),
63 		.nx		=	0,
64 	};
65 
66 	/* TODO: Add support for 5-level EPT. */
67 	tdp_mmu_init(vm, 4, &pte_masks);
68 }
69 
70 /* Allocate memory regions for nested VMX tests.
71  *
72  * Input Args:
73  *   vm - The VM to allocate guest-virtual addresses in.
74  *
75  * Output Args:
76  *   p_vmx_gva - The guest virtual address for the struct vmx_pages.
77  *
78  * Return:
79  *   Pointer to structure with the addresses of the VMX areas.
80  */
81 struct vmx_pages *
82 vcpu_alloc_vmx(struct kvm_vm *vm, vm_vaddr_t *p_vmx_gva)
83 {
84 	vm_vaddr_t vmx_gva = vm_vaddr_alloc_page(vm);
85 	struct vmx_pages *vmx = addr_gva2hva(vm, vmx_gva);
86 
87 	/* Setup of a region of guest memory for the vmxon region. */
88 	vmx->vmxon = (void *)vm_vaddr_alloc_page(vm);
89 	vmx->vmxon_hva = addr_gva2hva(vm, (uintptr_t)vmx->vmxon);
90 	vmx->vmxon_gpa = addr_gva2gpa(vm, (uintptr_t)vmx->vmxon);
91 
92 	/* Setup of a region of guest memory for a vmcs. */
93 	vmx->vmcs = (void *)vm_vaddr_alloc_page(vm);
94 	vmx->vmcs_hva = addr_gva2hva(vm, (uintptr_t)vmx->vmcs);
95 	vmx->vmcs_gpa = addr_gva2gpa(vm, (uintptr_t)vmx->vmcs);
96 
97 	/* Setup of a region of guest memory for the MSR bitmap. */
98 	vmx->msr = (void *)vm_vaddr_alloc_page(vm);
99 	vmx->msr_hva = addr_gva2hva(vm, (uintptr_t)vmx->msr);
100 	vmx->msr_gpa = addr_gva2gpa(vm, (uintptr_t)vmx->msr);
101 	memset(vmx->msr_hva, 0, getpagesize());
102 
103 	/* Setup of a region of guest memory for the shadow VMCS. */
104 	vmx->shadow_vmcs = (void *)vm_vaddr_alloc_page(vm);
105 	vmx->shadow_vmcs_hva = addr_gva2hva(vm, (uintptr_t)vmx->shadow_vmcs);
106 	vmx->shadow_vmcs_gpa = addr_gva2gpa(vm, (uintptr_t)vmx->shadow_vmcs);
107 
108 	/* Setup of a region of guest memory for the VMREAD and VMWRITE bitmaps. */
109 	vmx->vmread = (void *)vm_vaddr_alloc_page(vm);
110 	vmx->vmread_hva = addr_gva2hva(vm, (uintptr_t)vmx->vmread);
111 	vmx->vmread_gpa = addr_gva2gpa(vm, (uintptr_t)vmx->vmread);
112 	memset(vmx->vmread_hva, 0, getpagesize());
113 
114 	vmx->vmwrite = (void *)vm_vaddr_alloc_page(vm);
115 	vmx->vmwrite_hva = addr_gva2hva(vm, (uintptr_t)vmx->vmwrite);
116 	vmx->vmwrite_gpa = addr_gva2gpa(vm, (uintptr_t)vmx->vmwrite);
117 	memset(vmx->vmwrite_hva, 0, getpagesize());
118 
119 	if (vm->stage2_mmu.pgd_created)
120 		vmx->eptp_gpa = vm->stage2_mmu.pgd;
121 
122 	*p_vmx_gva = vmx_gva;
123 	return vmx;
124 }
125 
126 bool prepare_for_vmx_operation(struct vmx_pages *vmx)
127 {
128 	uint64_t feature_control;
129 	uint64_t required;
130 	unsigned long cr0;
131 	unsigned long cr4;
132 
133 	/*
134 	 * Ensure bits in CR0 and CR4 are valid in VMX operation:
135 	 * - Bit X is 1 in _FIXED0: bit X is fixed to 1 in CRx.
136 	 * - Bit X is 0 in _FIXED1: bit X is fixed to 0 in CRx.
137 	 */
138 	__asm__ __volatile__("mov %%cr0, %0" : "=r"(cr0) : : "memory");
139 	cr0 &= rdmsr(MSR_IA32_VMX_CR0_FIXED1);
140 	cr0 |= rdmsr(MSR_IA32_VMX_CR0_FIXED0);
141 	__asm__ __volatile__("mov %0, %%cr0" : : "r"(cr0) : "memory");
142 
143 	__asm__ __volatile__("mov %%cr4, %0" : "=r"(cr4) : : "memory");
144 	cr4 &= rdmsr(MSR_IA32_VMX_CR4_FIXED1);
145 	cr4 |= rdmsr(MSR_IA32_VMX_CR4_FIXED0);
146 	/* Enable VMX operation */
147 	cr4 |= X86_CR4_VMXE;
148 	__asm__ __volatile__("mov %0, %%cr4" : : "r"(cr4) : "memory");
149 
150 	/*
151 	 * Configure IA32_FEATURE_CONTROL MSR to allow VMXON:
152 	 *  Bit 0: Lock bit. If clear, VMXON causes a #GP.
153 	 *  Bit 2: Enables VMXON outside of SMX operation. If clear, VMXON
154 	 *    outside of SMX causes a #GP.
155 	 */
156 	required = FEAT_CTL_VMX_ENABLED_OUTSIDE_SMX;
157 	required |= FEAT_CTL_LOCKED;
158 	feature_control = rdmsr(MSR_IA32_FEAT_CTL);
159 	if ((feature_control & required) != required)
160 		wrmsr(MSR_IA32_FEAT_CTL, feature_control | required);
161 
162 	/* Enter VMX root operation. */
163 	*(uint32_t *)(vmx->vmxon) = vmcs_revision();
164 	if (vmxon(vmx->vmxon_gpa))
165 		return false;
166 
167 	return true;
168 }
169 
170 bool load_vmcs(struct vmx_pages *vmx)
171 {
172 	/* Load a VMCS. */
173 	*(uint32_t *)(vmx->vmcs) = vmcs_revision();
174 	if (vmclear(vmx->vmcs_gpa))
175 		return false;
176 
177 	if (vmptrld(vmx->vmcs_gpa))
178 		return false;
179 
180 	/* Setup shadow VMCS, do not load it yet. */
181 	*(uint32_t *)(vmx->shadow_vmcs) = vmcs_revision() | 0x80000000ul;
182 	if (vmclear(vmx->shadow_vmcs_gpa))
183 		return false;
184 
185 	return true;
186 }
187 
188 static bool ept_vpid_cap_supported(uint64_t mask)
189 {
190 	return rdmsr(MSR_IA32_VMX_EPT_VPID_CAP) & mask;
191 }
192 
193 bool ept_1g_pages_supported(void)
194 {
195 	return ept_vpid_cap_supported(VMX_EPT_VPID_CAP_1G_PAGES);
196 }
197 
198 /*
199  * Initialize the control fields to the most basic settings possible.
200  */
201 static inline void init_vmcs_control_fields(struct vmx_pages *vmx)
202 {
203 	uint32_t sec_exec_ctl = 0;
204 
205 	vmwrite(VIRTUAL_PROCESSOR_ID, 0);
206 	vmwrite(POSTED_INTR_NV, 0);
207 
208 	vmwrite(PIN_BASED_VM_EXEC_CONTROL, rdmsr(MSR_IA32_VMX_TRUE_PINBASED_CTLS));
209 
210 	if (vmx->eptp_gpa) {
211 		uint64_t eptp = vmx->eptp_gpa | EPTP_WB | EPTP_PWL_4;
212 
213 		TEST_ASSERT((vmx->eptp_gpa & ~PHYSICAL_PAGE_MASK) == 0,
214 			    "Illegal bits set in vmx->eptp_gpa");
215 
216 		if (ept_vpid_cap_supported(VMX_EPT_VPID_CAP_AD_BITS))
217 			eptp |= EPTP_AD_ENABLED;
218 
219 		vmwrite(EPT_POINTER, eptp);
220 		sec_exec_ctl |= SECONDARY_EXEC_ENABLE_EPT;
221 	}
222 
223 	if (!vmwrite(SECONDARY_VM_EXEC_CONTROL, sec_exec_ctl))
224 		vmwrite(CPU_BASED_VM_EXEC_CONTROL,
225 			rdmsr(MSR_IA32_VMX_TRUE_PROCBASED_CTLS) | CPU_BASED_ACTIVATE_SECONDARY_CONTROLS);
226 	else {
227 		vmwrite(CPU_BASED_VM_EXEC_CONTROL, rdmsr(MSR_IA32_VMX_TRUE_PROCBASED_CTLS));
228 		GUEST_ASSERT(!sec_exec_ctl);
229 	}
230 
231 	vmwrite(EXCEPTION_BITMAP, 0);
232 	vmwrite(PAGE_FAULT_ERROR_CODE_MASK, 0);
233 	vmwrite(PAGE_FAULT_ERROR_CODE_MATCH, -1); /* Never match */
234 	vmwrite(CR3_TARGET_COUNT, 0);
235 	vmwrite(VM_EXIT_CONTROLS, rdmsr(MSR_IA32_VMX_EXIT_CTLS) |
236 		VM_EXIT_HOST_ADDR_SPACE_SIZE);	  /* 64-bit host */
237 	vmwrite(VM_EXIT_MSR_STORE_COUNT, 0);
238 	vmwrite(VM_EXIT_MSR_LOAD_COUNT, 0);
239 	vmwrite(VM_ENTRY_CONTROLS, rdmsr(MSR_IA32_VMX_ENTRY_CTLS) |
240 		VM_ENTRY_IA32E_MODE);		  /* 64-bit guest */
241 	vmwrite(VM_ENTRY_MSR_LOAD_COUNT, 0);
242 	vmwrite(VM_ENTRY_INTR_INFO_FIELD, 0);
243 	vmwrite(TPR_THRESHOLD, 0);
244 
245 	vmwrite(CR0_GUEST_HOST_MASK, 0);
246 	vmwrite(CR4_GUEST_HOST_MASK, 0);
247 	vmwrite(CR0_READ_SHADOW, get_cr0());
248 	vmwrite(CR4_READ_SHADOW, get_cr4());
249 
250 	vmwrite(MSR_BITMAP, vmx->msr_gpa);
251 	vmwrite(VMREAD_BITMAP, vmx->vmread_gpa);
252 	vmwrite(VMWRITE_BITMAP, vmx->vmwrite_gpa);
253 }
254 
255 /*
256  * Initialize the host state fields based on the current host state, with
257  * the exception of HOST_RSP and HOST_RIP, which should be set by vmlaunch
258  * or vmresume.
259  */
260 static inline void init_vmcs_host_state(void)
261 {
262 	uint32_t exit_controls = vmreadz(VM_EXIT_CONTROLS);
263 
264 	vmwrite(HOST_ES_SELECTOR, get_es());
265 	vmwrite(HOST_CS_SELECTOR, get_cs());
266 	vmwrite(HOST_SS_SELECTOR, get_ss());
267 	vmwrite(HOST_DS_SELECTOR, get_ds());
268 	vmwrite(HOST_FS_SELECTOR, get_fs());
269 	vmwrite(HOST_GS_SELECTOR, get_gs());
270 	vmwrite(HOST_TR_SELECTOR, get_tr());
271 
272 	if (exit_controls & VM_EXIT_LOAD_IA32_PAT)
273 		vmwrite(HOST_IA32_PAT, rdmsr(MSR_IA32_CR_PAT));
274 	if (exit_controls & VM_EXIT_LOAD_IA32_EFER)
275 		vmwrite(HOST_IA32_EFER, rdmsr(MSR_EFER));
276 	if (exit_controls & VM_EXIT_LOAD_IA32_PERF_GLOBAL_CTRL)
277 		vmwrite(HOST_IA32_PERF_GLOBAL_CTRL,
278 			rdmsr(MSR_CORE_PERF_GLOBAL_CTRL));
279 
280 	vmwrite(HOST_IA32_SYSENTER_CS, rdmsr(MSR_IA32_SYSENTER_CS));
281 
282 	vmwrite(HOST_CR0, get_cr0());
283 	vmwrite(HOST_CR3, get_cr3());
284 	vmwrite(HOST_CR4, get_cr4());
285 	vmwrite(HOST_FS_BASE, rdmsr(MSR_FS_BASE));
286 	vmwrite(HOST_GS_BASE, rdmsr(MSR_GS_BASE));
287 	vmwrite(HOST_TR_BASE,
288 		get_desc64_base((struct desc64 *)(get_gdt().address + get_tr())));
289 	vmwrite(HOST_GDTR_BASE, get_gdt().address);
290 	vmwrite(HOST_IDTR_BASE, get_idt().address);
291 	vmwrite(HOST_IA32_SYSENTER_ESP, rdmsr(MSR_IA32_SYSENTER_ESP));
292 	vmwrite(HOST_IA32_SYSENTER_EIP, rdmsr(MSR_IA32_SYSENTER_EIP));
293 }
294 
295 /*
296  * Initialize the guest state fields essentially as a clone of
297  * the host state fields. Some host state fields have fixed
298  * values, and we set the corresponding guest state fields accordingly.
299  */
300 static inline void init_vmcs_guest_state(void *rip, void *rsp)
301 {
302 	vmwrite(GUEST_ES_SELECTOR, vmreadz(HOST_ES_SELECTOR));
303 	vmwrite(GUEST_CS_SELECTOR, vmreadz(HOST_CS_SELECTOR));
304 	vmwrite(GUEST_SS_SELECTOR, vmreadz(HOST_SS_SELECTOR));
305 	vmwrite(GUEST_DS_SELECTOR, vmreadz(HOST_DS_SELECTOR));
306 	vmwrite(GUEST_FS_SELECTOR, vmreadz(HOST_FS_SELECTOR));
307 	vmwrite(GUEST_GS_SELECTOR, vmreadz(HOST_GS_SELECTOR));
308 	vmwrite(GUEST_LDTR_SELECTOR, 0);
309 	vmwrite(GUEST_TR_SELECTOR, vmreadz(HOST_TR_SELECTOR));
310 	vmwrite(GUEST_INTR_STATUS, 0);
311 	vmwrite(GUEST_PML_INDEX, 0);
312 
313 	vmwrite(VMCS_LINK_POINTER, -1ll);
314 	vmwrite(GUEST_IA32_DEBUGCTL, 0);
315 	vmwrite(GUEST_IA32_PAT, vmreadz(HOST_IA32_PAT));
316 	vmwrite(GUEST_IA32_EFER, vmreadz(HOST_IA32_EFER));
317 	vmwrite(GUEST_IA32_PERF_GLOBAL_CTRL,
318 		vmreadz(HOST_IA32_PERF_GLOBAL_CTRL));
319 
320 	vmwrite(GUEST_ES_LIMIT, -1);
321 	vmwrite(GUEST_CS_LIMIT, -1);
322 	vmwrite(GUEST_SS_LIMIT, -1);
323 	vmwrite(GUEST_DS_LIMIT, -1);
324 	vmwrite(GUEST_FS_LIMIT, -1);
325 	vmwrite(GUEST_GS_LIMIT, -1);
326 	vmwrite(GUEST_LDTR_LIMIT, -1);
327 	vmwrite(GUEST_TR_LIMIT, 0x67);
328 	vmwrite(GUEST_GDTR_LIMIT, 0xffff);
329 	vmwrite(GUEST_IDTR_LIMIT, 0xffff);
330 	vmwrite(GUEST_ES_AR_BYTES,
331 		vmreadz(GUEST_ES_SELECTOR) == 0 ? 0x10000 : 0xc093);
332 	vmwrite(GUEST_CS_AR_BYTES, 0xa09b);
333 	vmwrite(GUEST_SS_AR_BYTES, 0xc093);
334 	vmwrite(GUEST_DS_AR_BYTES,
335 		vmreadz(GUEST_DS_SELECTOR) == 0 ? 0x10000 : 0xc093);
336 	vmwrite(GUEST_FS_AR_BYTES,
337 		vmreadz(GUEST_FS_SELECTOR) == 0 ? 0x10000 : 0xc093);
338 	vmwrite(GUEST_GS_AR_BYTES,
339 		vmreadz(GUEST_GS_SELECTOR) == 0 ? 0x10000 : 0xc093);
340 	vmwrite(GUEST_LDTR_AR_BYTES, 0x10000);
341 	vmwrite(GUEST_TR_AR_BYTES, 0x8b);
342 	vmwrite(GUEST_INTERRUPTIBILITY_INFO, 0);
343 	vmwrite(GUEST_ACTIVITY_STATE, 0);
344 	vmwrite(GUEST_SYSENTER_CS, vmreadz(HOST_IA32_SYSENTER_CS));
345 	vmwrite(VMX_PREEMPTION_TIMER_VALUE, 0);
346 
347 	vmwrite(GUEST_CR0, vmreadz(HOST_CR0));
348 	vmwrite(GUEST_CR3, vmreadz(HOST_CR3));
349 	vmwrite(GUEST_CR4, vmreadz(HOST_CR4));
350 	vmwrite(GUEST_ES_BASE, 0);
351 	vmwrite(GUEST_CS_BASE, 0);
352 	vmwrite(GUEST_SS_BASE, 0);
353 	vmwrite(GUEST_DS_BASE, 0);
354 	vmwrite(GUEST_FS_BASE, vmreadz(HOST_FS_BASE));
355 	vmwrite(GUEST_GS_BASE, vmreadz(HOST_GS_BASE));
356 	vmwrite(GUEST_LDTR_BASE, 0);
357 	vmwrite(GUEST_TR_BASE, vmreadz(HOST_TR_BASE));
358 	vmwrite(GUEST_GDTR_BASE, vmreadz(HOST_GDTR_BASE));
359 	vmwrite(GUEST_IDTR_BASE, vmreadz(HOST_IDTR_BASE));
360 	vmwrite(GUEST_DR7, 0x400);
361 	vmwrite(GUEST_RSP, (uint64_t)rsp);
362 	vmwrite(GUEST_RIP, (uint64_t)rip);
363 	vmwrite(GUEST_RFLAGS, 2);
364 	vmwrite(GUEST_PENDING_DBG_EXCEPTIONS, 0);
365 	vmwrite(GUEST_SYSENTER_ESP, vmreadz(HOST_IA32_SYSENTER_ESP));
366 	vmwrite(GUEST_SYSENTER_EIP, vmreadz(HOST_IA32_SYSENTER_EIP));
367 }
368 
369 void prepare_vmcs(struct vmx_pages *vmx, void *guest_rip, void *guest_rsp)
370 {
371 	init_vmcs_control_fields(vmx);
372 	init_vmcs_host_state();
373 	init_vmcs_guest_state(guest_rip, guest_rsp);
374 }
375 
376 bool kvm_cpu_has_ept(void)
377 {
378 	uint64_t ctrl;
379 
380 	if (!kvm_cpu_has(X86_FEATURE_VMX))
381 		return false;
382 
383 	ctrl = kvm_get_feature_msr(MSR_IA32_VMX_TRUE_PROCBASED_CTLS) >> 32;
384 	if (!(ctrl & CPU_BASED_ACTIVATE_SECONDARY_CONTROLS))
385 		return false;
386 
387 	ctrl = kvm_get_feature_msr(MSR_IA32_VMX_PROCBASED_CTLS2) >> 32;
388 	return ctrl & SECONDARY_EXEC_ENABLE_EPT;
389 }
390 
391 void prepare_virtualize_apic_accesses(struct vmx_pages *vmx, struct kvm_vm *vm)
392 {
393 	vmx->apic_access = (void *)vm_vaddr_alloc_page(vm);
394 	vmx->apic_access_hva = addr_gva2hva(vm, (uintptr_t)vmx->apic_access);
395 	vmx->apic_access_gpa = addr_gva2gpa(vm, (uintptr_t)vmx->apic_access);
396 }
397