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1 /*
2  * tools/testing/selftests/kvm/lib/x86_64/vmx.c
3  *
4  * Copyright (C) 2018, Google LLC.
5  *
6  * This work is licensed under the terms of the GNU GPL, version 2.
7  */
8 
9 #define _GNU_SOURCE /* for program_invocation_name */
10 
11 #include "test_util.h"
12 #include "kvm_util.h"
13 #include "processor.h"
14 #include "vmx.h"
15 
16 bool enable_evmcs;
17 
18 /* Allocate memory regions for nested VMX tests.
19  *
20  * Input Args:
21  *   vm - The VM to allocate guest-virtual addresses in.
22  *
23  * Output Args:
24  *   p_vmx_gva - The guest virtual address for the struct vmx_pages.
25  *
26  * Return:
27  *   Pointer to structure with the addresses of the VMX areas.
28  */
29 struct vmx_pages *
vcpu_alloc_vmx(struct kvm_vm * vm,vm_vaddr_t * p_vmx_gva)30 vcpu_alloc_vmx(struct kvm_vm *vm, vm_vaddr_t *p_vmx_gva)
31 {
32 	vm_vaddr_t vmx_gva = vm_vaddr_alloc(vm, getpagesize(), 0x10000, 0, 0);
33 	struct vmx_pages *vmx = addr_gva2hva(vm, vmx_gva);
34 
35 	/* Setup of a region of guest memory for the vmxon region. */
36 	vmx->vmxon = (void *)vm_vaddr_alloc(vm, getpagesize(), 0x10000, 0, 0);
37 	vmx->vmxon_hva = addr_gva2hva(vm, (uintptr_t)vmx->vmxon);
38 	vmx->vmxon_gpa = addr_gva2gpa(vm, (uintptr_t)vmx->vmxon);
39 
40 	/* Setup of a region of guest memory for a vmcs. */
41 	vmx->vmcs = (void *)vm_vaddr_alloc(vm, getpagesize(), 0x10000, 0, 0);
42 	vmx->vmcs_hva = addr_gva2hva(vm, (uintptr_t)vmx->vmcs);
43 	vmx->vmcs_gpa = addr_gva2gpa(vm, (uintptr_t)vmx->vmcs);
44 
45 	/* Setup of a region of guest memory for the MSR bitmap. */
46 	vmx->msr = (void *)vm_vaddr_alloc(vm, getpagesize(), 0x10000, 0, 0);
47 	vmx->msr_hva = addr_gva2hva(vm, (uintptr_t)vmx->msr);
48 	vmx->msr_gpa = addr_gva2gpa(vm, (uintptr_t)vmx->msr);
49 	memset(vmx->msr_hva, 0, getpagesize());
50 
51 	/* Setup of a region of guest memory for the shadow VMCS. */
52 	vmx->shadow_vmcs = (void *)vm_vaddr_alloc(vm, getpagesize(), 0x10000, 0, 0);
53 	vmx->shadow_vmcs_hva = addr_gva2hva(vm, (uintptr_t)vmx->shadow_vmcs);
54 	vmx->shadow_vmcs_gpa = addr_gva2gpa(vm, (uintptr_t)vmx->shadow_vmcs);
55 
56 	/* Setup of a region of guest memory for the VMREAD and VMWRITE bitmaps. */
57 	vmx->vmread = (void *)vm_vaddr_alloc(vm, getpagesize(), 0x10000, 0, 0);
58 	vmx->vmread_hva = addr_gva2hva(vm, (uintptr_t)vmx->vmread);
59 	vmx->vmread_gpa = addr_gva2gpa(vm, (uintptr_t)vmx->vmread);
60 	memset(vmx->vmread_hva, 0, getpagesize());
61 
62 	vmx->vmwrite = (void *)vm_vaddr_alloc(vm, getpagesize(), 0x10000, 0, 0);
63 	vmx->vmwrite_hva = addr_gva2hva(vm, (uintptr_t)vmx->vmwrite);
64 	vmx->vmwrite_gpa = addr_gva2gpa(vm, (uintptr_t)vmx->vmwrite);
65 	memset(vmx->vmwrite_hva, 0, getpagesize());
66 
67 	/* Setup of a region of guest memory for the VP Assist page. */
68 	vmx->vp_assist = (void *)vm_vaddr_alloc(vm, getpagesize(),
69 						0x10000, 0, 0);
70 	vmx->vp_assist_hva = addr_gva2hva(vm, (uintptr_t)vmx->vp_assist);
71 	vmx->vp_assist_gpa = addr_gva2gpa(vm, (uintptr_t)vmx->vp_assist);
72 
73 	/* Setup of a region of guest memory for the enlightened VMCS. */
74 	vmx->enlightened_vmcs = (void *)vm_vaddr_alloc(vm, getpagesize(),
75 						       0x10000, 0, 0);
76 	vmx->enlightened_vmcs_hva =
77 		addr_gva2hva(vm, (uintptr_t)vmx->enlightened_vmcs);
78 	vmx->enlightened_vmcs_gpa =
79 		addr_gva2gpa(vm, (uintptr_t)vmx->enlightened_vmcs);
80 
81 	*p_vmx_gva = vmx_gva;
82 	return vmx;
83 }
84 
prepare_for_vmx_operation(struct vmx_pages * vmx)85 bool prepare_for_vmx_operation(struct vmx_pages *vmx)
86 {
87 	uint64_t feature_control;
88 	uint64_t required;
89 	unsigned long cr0;
90 	unsigned long cr4;
91 
92 	/*
93 	 * Ensure bits in CR0 and CR4 are valid in VMX operation:
94 	 * - Bit X is 1 in _FIXED0: bit X is fixed to 1 in CRx.
95 	 * - Bit X is 0 in _FIXED1: bit X is fixed to 0 in CRx.
96 	 */
97 	__asm__ __volatile__("mov %%cr0, %0" : "=r"(cr0) : : "memory");
98 	cr0 &= rdmsr(MSR_IA32_VMX_CR0_FIXED1);
99 	cr0 |= rdmsr(MSR_IA32_VMX_CR0_FIXED0);
100 	__asm__ __volatile__("mov %0, %%cr0" : : "r"(cr0) : "memory");
101 
102 	__asm__ __volatile__("mov %%cr4, %0" : "=r"(cr4) : : "memory");
103 	cr4 &= rdmsr(MSR_IA32_VMX_CR4_FIXED1);
104 	cr4 |= rdmsr(MSR_IA32_VMX_CR4_FIXED0);
105 	/* Enable VMX operation */
106 	cr4 |= X86_CR4_VMXE;
107 	__asm__ __volatile__("mov %0, %%cr4" : : "r"(cr4) : "memory");
108 
109 	/*
110 	 * Configure IA32_FEATURE_CONTROL MSR to allow VMXON:
111 	 *  Bit 0: Lock bit. If clear, VMXON causes a #GP.
112 	 *  Bit 2: Enables VMXON outside of SMX operation. If clear, VMXON
113 	 *    outside of SMX causes a #GP.
114 	 */
115 	required = FEATURE_CONTROL_VMXON_ENABLED_OUTSIDE_SMX;
116 	required |= FEATURE_CONTROL_LOCKED;
117 	feature_control = rdmsr(MSR_IA32_FEATURE_CONTROL);
118 	if ((feature_control & required) != required)
119 		wrmsr(MSR_IA32_FEATURE_CONTROL, feature_control | required);
120 
121 	/* Enter VMX root operation. */
122 	*(uint32_t *)(vmx->vmxon) = vmcs_revision();
123 	if (vmxon(vmx->vmxon_gpa))
124 		return false;
125 
126 	return true;
127 }
128 
load_vmcs(struct vmx_pages * vmx)129 bool load_vmcs(struct vmx_pages *vmx)
130 {
131 	if (!enable_evmcs) {
132 		/* Load a VMCS. */
133 		*(uint32_t *)(vmx->vmcs) = vmcs_revision();
134 		if (vmclear(vmx->vmcs_gpa))
135 			return false;
136 
137 		if (vmptrld(vmx->vmcs_gpa))
138 			return false;
139 
140 		/* Setup shadow VMCS, do not load it yet. */
141 		*(uint32_t *)(vmx->shadow_vmcs) =
142 			vmcs_revision() | 0x80000000ul;
143 		if (vmclear(vmx->shadow_vmcs_gpa))
144 			return false;
145 	} else {
146 		if (evmcs_vmptrld(vmx->enlightened_vmcs_gpa,
147 				  vmx->enlightened_vmcs))
148 			return false;
149 		current_evmcs->revision_id = vmcs_revision();
150 	}
151 
152 	return true;
153 }
154 
155 /*
156  * Initialize the control fields to the most basic settings possible.
157  */
init_vmcs_control_fields(struct vmx_pages * vmx)158 static inline void init_vmcs_control_fields(struct vmx_pages *vmx)
159 {
160 	vmwrite(VIRTUAL_PROCESSOR_ID, 0);
161 	vmwrite(POSTED_INTR_NV, 0);
162 
163 	vmwrite(PIN_BASED_VM_EXEC_CONTROL, rdmsr(MSR_IA32_VMX_TRUE_PINBASED_CTLS));
164 	if (!vmwrite(SECONDARY_VM_EXEC_CONTROL, 0))
165 		vmwrite(CPU_BASED_VM_EXEC_CONTROL,
166 			rdmsr(MSR_IA32_VMX_TRUE_PROCBASED_CTLS) | CPU_BASED_ACTIVATE_SECONDARY_CONTROLS);
167 	else
168 		vmwrite(CPU_BASED_VM_EXEC_CONTROL, rdmsr(MSR_IA32_VMX_TRUE_PROCBASED_CTLS));
169 	vmwrite(EXCEPTION_BITMAP, 0);
170 	vmwrite(PAGE_FAULT_ERROR_CODE_MASK, 0);
171 	vmwrite(PAGE_FAULT_ERROR_CODE_MATCH, -1); /* Never match */
172 	vmwrite(CR3_TARGET_COUNT, 0);
173 	vmwrite(VM_EXIT_CONTROLS, rdmsr(MSR_IA32_VMX_EXIT_CTLS) |
174 		VM_EXIT_HOST_ADDR_SPACE_SIZE);	  /* 64-bit host */
175 	vmwrite(VM_EXIT_MSR_STORE_COUNT, 0);
176 	vmwrite(VM_EXIT_MSR_LOAD_COUNT, 0);
177 	vmwrite(VM_ENTRY_CONTROLS, rdmsr(MSR_IA32_VMX_ENTRY_CTLS) |
178 		VM_ENTRY_IA32E_MODE);		  /* 64-bit guest */
179 	vmwrite(VM_ENTRY_MSR_LOAD_COUNT, 0);
180 	vmwrite(VM_ENTRY_INTR_INFO_FIELD, 0);
181 	vmwrite(TPR_THRESHOLD, 0);
182 
183 	vmwrite(CR0_GUEST_HOST_MASK, 0);
184 	vmwrite(CR4_GUEST_HOST_MASK, 0);
185 	vmwrite(CR0_READ_SHADOW, get_cr0());
186 	vmwrite(CR4_READ_SHADOW, get_cr4());
187 
188 	vmwrite(MSR_BITMAP, vmx->msr_gpa);
189 	vmwrite(VMREAD_BITMAP, vmx->vmread_gpa);
190 	vmwrite(VMWRITE_BITMAP, vmx->vmwrite_gpa);
191 }
192 
193 /*
194  * Initialize the host state fields based on the current host state, with
195  * the exception of HOST_RSP and HOST_RIP, which should be set by vmlaunch
196  * or vmresume.
197  */
init_vmcs_host_state(void)198 static inline void init_vmcs_host_state(void)
199 {
200 	uint32_t exit_controls = vmreadz(VM_EXIT_CONTROLS);
201 
202 	vmwrite(HOST_ES_SELECTOR, get_es());
203 	vmwrite(HOST_CS_SELECTOR, get_cs());
204 	vmwrite(HOST_SS_SELECTOR, get_ss());
205 	vmwrite(HOST_DS_SELECTOR, get_ds());
206 	vmwrite(HOST_FS_SELECTOR, get_fs());
207 	vmwrite(HOST_GS_SELECTOR, get_gs());
208 	vmwrite(HOST_TR_SELECTOR, get_tr());
209 
210 	if (exit_controls & VM_EXIT_LOAD_IA32_PAT)
211 		vmwrite(HOST_IA32_PAT, rdmsr(MSR_IA32_CR_PAT));
212 	if (exit_controls & VM_EXIT_LOAD_IA32_EFER)
213 		vmwrite(HOST_IA32_EFER, rdmsr(MSR_EFER));
214 	if (exit_controls & VM_EXIT_LOAD_IA32_PERF_GLOBAL_CTRL)
215 		vmwrite(HOST_IA32_PERF_GLOBAL_CTRL,
216 			rdmsr(MSR_CORE_PERF_GLOBAL_CTRL));
217 
218 	vmwrite(HOST_IA32_SYSENTER_CS, rdmsr(MSR_IA32_SYSENTER_CS));
219 
220 	vmwrite(HOST_CR0, get_cr0());
221 	vmwrite(HOST_CR3, get_cr3());
222 	vmwrite(HOST_CR4, get_cr4());
223 	vmwrite(HOST_FS_BASE, rdmsr(MSR_FS_BASE));
224 	vmwrite(HOST_GS_BASE, rdmsr(MSR_GS_BASE));
225 	vmwrite(HOST_TR_BASE,
226 		get_desc64_base((struct desc64 *)(get_gdt_base() + get_tr())));
227 	vmwrite(HOST_GDTR_BASE, get_gdt_base());
228 	vmwrite(HOST_IDTR_BASE, get_idt_base());
229 	vmwrite(HOST_IA32_SYSENTER_ESP, rdmsr(MSR_IA32_SYSENTER_ESP));
230 	vmwrite(HOST_IA32_SYSENTER_EIP, rdmsr(MSR_IA32_SYSENTER_EIP));
231 }
232 
233 /*
234  * Initialize the guest state fields essentially as a clone of
235  * the host state fields. Some host state fields have fixed
236  * values, and we set the corresponding guest state fields accordingly.
237  */
init_vmcs_guest_state(void * rip,void * rsp)238 static inline void init_vmcs_guest_state(void *rip, void *rsp)
239 {
240 	vmwrite(GUEST_ES_SELECTOR, vmreadz(HOST_ES_SELECTOR));
241 	vmwrite(GUEST_CS_SELECTOR, vmreadz(HOST_CS_SELECTOR));
242 	vmwrite(GUEST_SS_SELECTOR, vmreadz(HOST_SS_SELECTOR));
243 	vmwrite(GUEST_DS_SELECTOR, vmreadz(HOST_DS_SELECTOR));
244 	vmwrite(GUEST_FS_SELECTOR, vmreadz(HOST_FS_SELECTOR));
245 	vmwrite(GUEST_GS_SELECTOR, vmreadz(HOST_GS_SELECTOR));
246 	vmwrite(GUEST_LDTR_SELECTOR, 0);
247 	vmwrite(GUEST_TR_SELECTOR, vmreadz(HOST_TR_SELECTOR));
248 	vmwrite(GUEST_INTR_STATUS, 0);
249 	vmwrite(GUEST_PML_INDEX, 0);
250 
251 	vmwrite(VMCS_LINK_POINTER, -1ll);
252 	vmwrite(GUEST_IA32_DEBUGCTL, 0);
253 	vmwrite(GUEST_IA32_PAT, vmreadz(HOST_IA32_PAT));
254 	vmwrite(GUEST_IA32_EFER, vmreadz(HOST_IA32_EFER));
255 	vmwrite(GUEST_IA32_PERF_GLOBAL_CTRL,
256 		vmreadz(HOST_IA32_PERF_GLOBAL_CTRL));
257 
258 	vmwrite(GUEST_ES_LIMIT, -1);
259 	vmwrite(GUEST_CS_LIMIT, -1);
260 	vmwrite(GUEST_SS_LIMIT, -1);
261 	vmwrite(GUEST_DS_LIMIT, -1);
262 	vmwrite(GUEST_FS_LIMIT, -1);
263 	vmwrite(GUEST_GS_LIMIT, -1);
264 	vmwrite(GUEST_LDTR_LIMIT, -1);
265 	vmwrite(GUEST_TR_LIMIT, 0x67);
266 	vmwrite(GUEST_GDTR_LIMIT, 0xffff);
267 	vmwrite(GUEST_IDTR_LIMIT, 0xffff);
268 	vmwrite(GUEST_ES_AR_BYTES,
269 		vmreadz(GUEST_ES_SELECTOR) == 0 ? 0x10000 : 0xc093);
270 	vmwrite(GUEST_CS_AR_BYTES, 0xa09b);
271 	vmwrite(GUEST_SS_AR_BYTES, 0xc093);
272 	vmwrite(GUEST_DS_AR_BYTES,
273 		vmreadz(GUEST_DS_SELECTOR) == 0 ? 0x10000 : 0xc093);
274 	vmwrite(GUEST_FS_AR_BYTES,
275 		vmreadz(GUEST_FS_SELECTOR) == 0 ? 0x10000 : 0xc093);
276 	vmwrite(GUEST_GS_AR_BYTES,
277 		vmreadz(GUEST_GS_SELECTOR) == 0 ? 0x10000 : 0xc093);
278 	vmwrite(GUEST_LDTR_AR_BYTES, 0x10000);
279 	vmwrite(GUEST_TR_AR_BYTES, 0x8b);
280 	vmwrite(GUEST_INTERRUPTIBILITY_INFO, 0);
281 	vmwrite(GUEST_ACTIVITY_STATE, 0);
282 	vmwrite(GUEST_SYSENTER_CS, vmreadz(HOST_IA32_SYSENTER_CS));
283 	vmwrite(VMX_PREEMPTION_TIMER_VALUE, 0);
284 
285 	vmwrite(GUEST_CR0, vmreadz(HOST_CR0));
286 	vmwrite(GUEST_CR3, vmreadz(HOST_CR3));
287 	vmwrite(GUEST_CR4, vmreadz(HOST_CR4));
288 	vmwrite(GUEST_ES_BASE, 0);
289 	vmwrite(GUEST_CS_BASE, 0);
290 	vmwrite(GUEST_SS_BASE, 0);
291 	vmwrite(GUEST_DS_BASE, 0);
292 	vmwrite(GUEST_FS_BASE, vmreadz(HOST_FS_BASE));
293 	vmwrite(GUEST_GS_BASE, vmreadz(HOST_GS_BASE));
294 	vmwrite(GUEST_LDTR_BASE, 0);
295 	vmwrite(GUEST_TR_BASE, vmreadz(HOST_TR_BASE));
296 	vmwrite(GUEST_GDTR_BASE, vmreadz(HOST_GDTR_BASE));
297 	vmwrite(GUEST_IDTR_BASE, vmreadz(HOST_IDTR_BASE));
298 	vmwrite(GUEST_DR7, 0x400);
299 	vmwrite(GUEST_RSP, (uint64_t)rsp);
300 	vmwrite(GUEST_RIP, (uint64_t)rip);
301 	vmwrite(GUEST_RFLAGS, 2);
302 	vmwrite(GUEST_PENDING_DBG_EXCEPTIONS, 0);
303 	vmwrite(GUEST_SYSENTER_ESP, vmreadz(HOST_IA32_SYSENTER_ESP));
304 	vmwrite(GUEST_SYSENTER_EIP, vmreadz(HOST_IA32_SYSENTER_EIP));
305 }
306 
prepare_vmcs(struct vmx_pages * vmx,void * guest_rip,void * guest_rsp)307 void prepare_vmcs(struct vmx_pages *vmx, void *guest_rip, void *guest_rsp)
308 {
309 	init_vmcs_control_fields(vmx);
310 	init_vmcs_host_state();
311 	init_vmcs_guest_state(guest_rip, guest_rsp);
312 }
313