1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * KVM_GET/SET_* tests
4  *
5  * Copyright (C) 2018, Red Hat, Inc.
6  *
7  * Tests for vCPU state save/restore, including nested guest state.
8  */
9 #define _GNU_SOURCE /* for program_invocation_short_name */
10 #include <fcntl.h>
11 #include <stdio.h>
12 #include <stdlib.h>
13 #include <string.h>
14 #include <sys/ioctl.h>
15 
16 #include "test_util.h"
17 
18 #include "kvm_util.h"
19 #include "processor.h"
20 #include "vmx.h"
21 #include "svm_util.h"
22 
23 #define VCPU_ID		5
24 #define L2_GUEST_STACK_SIZE 256
25 
svm_l2_guest_code(void)26 void svm_l2_guest_code(void)
27 {
28 	GUEST_SYNC(4);
29 	/* Exit to L1 */
30 	vmcall();
31 	GUEST_SYNC(6);
32 	/* Done, exit to L1 and never come back.  */
33 	vmcall();
34 }
35 
svm_l1_guest_code(struct svm_test_data * svm)36 static void svm_l1_guest_code(struct svm_test_data *svm)
37 {
38 	unsigned long l2_guest_stack[L2_GUEST_STACK_SIZE];
39 	struct vmcb *vmcb = svm->vmcb;
40 
41 	GUEST_ASSERT(svm->vmcb_gpa);
42 	/* Prepare for L2 execution. */
43 	generic_svm_setup(svm, svm_l2_guest_code,
44 			  &l2_guest_stack[L2_GUEST_STACK_SIZE]);
45 
46 	GUEST_SYNC(3);
47 	run_guest(vmcb, svm->vmcb_gpa);
48 	GUEST_ASSERT(vmcb->control.exit_code == SVM_EXIT_VMMCALL);
49 	GUEST_SYNC(5);
50 	vmcb->save.rip += 3;
51 	run_guest(vmcb, svm->vmcb_gpa);
52 	GUEST_ASSERT(vmcb->control.exit_code == SVM_EXIT_VMMCALL);
53 	GUEST_SYNC(7);
54 }
55 
vmx_l2_guest_code(void)56 void vmx_l2_guest_code(void)
57 {
58 	GUEST_SYNC(6);
59 
60 	/* Exit to L1 */
61 	vmcall();
62 
63 	/* L1 has now set up a shadow VMCS for us.  */
64 	GUEST_ASSERT(vmreadz(GUEST_RIP) == 0xc0ffee);
65 	GUEST_SYNC(10);
66 	GUEST_ASSERT(vmreadz(GUEST_RIP) == 0xc0ffee);
67 	GUEST_ASSERT(!vmwrite(GUEST_RIP, 0xc0fffee));
68 	GUEST_SYNC(11);
69 	GUEST_ASSERT(vmreadz(GUEST_RIP) == 0xc0fffee);
70 	GUEST_ASSERT(!vmwrite(GUEST_RIP, 0xc0ffffee));
71 	GUEST_SYNC(12);
72 
73 	/* Done, exit to L1 and never come back.  */
74 	vmcall();
75 }
76 
vmx_l1_guest_code(struct vmx_pages * vmx_pages)77 static void vmx_l1_guest_code(struct vmx_pages *vmx_pages)
78 {
79 	unsigned long l2_guest_stack[L2_GUEST_STACK_SIZE];
80 
81 	GUEST_ASSERT(vmx_pages->vmcs_gpa);
82 	GUEST_ASSERT(prepare_for_vmx_operation(vmx_pages));
83 	GUEST_SYNC(3);
84 	GUEST_ASSERT(load_vmcs(vmx_pages));
85 	GUEST_ASSERT(vmptrstz() == vmx_pages->vmcs_gpa);
86 
87 	GUEST_SYNC(4);
88 	GUEST_ASSERT(vmptrstz() == vmx_pages->vmcs_gpa);
89 
90 	prepare_vmcs(vmx_pages, vmx_l2_guest_code,
91 		     &l2_guest_stack[L2_GUEST_STACK_SIZE]);
92 
93 	GUEST_SYNC(5);
94 	GUEST_ASSERT(vmptrstz() == vmx_pages->vmcs_gpa);
95 	GUEST_ASSERT(!vmlaunch());
96 	GUEST_ASSERT(vmptrstz() == vmx_pages->vmcs_gpa);
97 	GUEST_ASSERT(vmreadz(VM_EXIT_REASON) == EXIT_REASON_VMCALL);
98 
99 	/* Check that the launched state is preserved.  */
100 	GUEST_ASSERT(vmlaunch());
101 
102 	GUEST_ASSERT(!vmresume());
103 	GUEST_ASSERT(vmreadz(VM_EXIT_REASON) == EXIT_REASON_VMCALL);
104 
105 	GUEST_SYNC(7);
106 	GUEST_ASSERT(vmreadz(VM_EXIT_REASON) == EXIT_REASON_VMCALL);
107 
108 	GUEST_ASSERT(!vmresume());
109 	GUEST_ASSERT(vmreadz(VM_EXIT_REASON) == EXIT_REASON_VMCALL);
110 
111 	vmwrite(GUEST_RIP, vmreadz(GUEST_RIP) + 3);
112 
113 	vmwrite(SECONDARY_VM_EXEC_CONTROL, SECONDARY_EXEC_SHADOW_VMCS);
114 	vmwrite(VMCS_LINK_POINTER, vmx_pages->shadow_vmcs_gpa);
115 
116 	GUEST_ASSERT(!vmptrld(vmx_pages->shadow_vmcs_gpa));
117 	GUEST_ASSERT(vmlaunch());
118 	GUEST_SYNC(8);
119 	GUEST_ASSERT(vmlaunch());
120 	GUEST_ASSERT(vmresume());
121 
122 	vmwrite(GUEST_RIP, 0xc0ffee);
123 	GUEST_SYNC(9);
124 	GUEST_ASSERT(vmreadz(GUEST_RIP) == 0xc0ffee);
125 
126 	GUEST_ASSERT(!vmptrld(vmx_pages->vmcs_gpa));
127 	GUEST_ASSERT(!vmresume());
128 	GUEST_ASSERT(vmreadz(VM_EXIT_REASON) == EXIT_REASON_VMCALL);
129 
130 	GUEST_ASSERT(!vmptrld(vmx_pages->shadow_vmcs_gpa));
131 	GUEST_ASSERT(vmreadz(GUEST_RIP) == 0xc0ffffee);
132 	GUEST_ASSERT(vmlaunch());
133 	GUEST_ASSERT(vmresume());
134 	GUEST_SYNC(13);
135 	GUEST_ASSERT(vmreadz(GUEST_RIP) == 0xc0ffffee);
136 	GUEST_ASSERT(vmlaunch());
137 	GUEST_ASSERT(vmresume());
138 }
139 
guest_code(void * arg)140 static void __attribute__((__flatten__)) guest_code(void *arg)
141 {
142 	GUEST_SYNC(1);
143 	GUEST_SYNC(2);
144 
145 	if (arg) {
146 		if (cpu_has_svm())
147 			svm_l1_guest_code(arg);
148 		else
149 			vmx_l1_guest_code(arg);
150 	}
151 
152 	GUEST_DONE();
153 }
154 
main(int argc,char * argv[])155 int main(int argc, char *argv[])
156 {
157 	vm_vaddr_t nested_gva = 0;
158 
159 	struct kvm_regs regs1, regs2;
160 	struct kvm_vm *vm;
161 	struct kvm_run *run;
162 	struct kvm_x86_state *state;
163 	struct ucall uc;
164 	int stage;
165 
166 	/* Create VM */
167 	vm = vm_create_default(VCPU_ID, 0, guest_code);
168 	run = vcpu_state(vm, VCPU_ID);
169 
170 	vcpu_regs_get(vm, VCPU_ID, &regs1);
171 
172 	if (kvm_check_cap(KVM_CAP_NESTED_STATE)) {
173 		if (nested_svm_supported())
174 			vcpu_alloc_svm(vm, &nested_gva);
175 		else if (nested_vmx_supported())
176 			vcpu_alloc_vmx(vm, &nested_gva);
177 	}
178 
179 	if (!nested_gva)
180 		pr_info("will skip nested state checks\n");
181 
182 	vcpu_args_set(vm, VCPU_ID, 1, nested_gva);
183 
184 	for (stage = 1;; stage++) {
185 		_vcpu_run(vm, VCPU_ID);
186 		TEST_ASSERT(run->exit_reason == KVM_EXIT_IO,
187 			    "Stage %d: unexpected exit reason: %u (%s),\n",
188 			    stage, run->exit_reason,
189 			    exit_reason_str(run->exit_reason));
190 
191 		switch (get_ucall(vm, VCPU_ID, &uc)) {
192 		case UCALL_ABORT:
193 			TEST_FAIL("%s at %s:%ld", (const char *)uc.args[0],
194 			       	  __FILE__, uc.args[1]);
195 			/* NOT REACHED */
196 		case UCALL_SYNC:
197 			break;
198 		case UCALL_DONE:
199 			goto done;
200 		default:
201 			TEST_FAIL("Unknown ucall %lu", uc.cmd);
202 		}
203 
204 		/* UCALL_SYNC is handled here.  */
205 		TEST_ASSERT(!strcmp((const char *)uc.args[0], "hello") &&
206 			    uc.args[1] == stage, "Stage %d: Unexpected register values vmexit, got %lx",
207 			    stage, (ulong)uc.args[1]);
208 
209 		state = vcpu_save_state(vm, VCPU_ID);
210 		memset(&regs1, 0, sizeof(regs1));
211 		vcpu_regs_get(vm, VCPU_ID, &regs1);
212 
213 		kvm_vm_release(vm);
214 
215 		/* Restore state in a new VM.  */
216 		kvm_vm_restart(vm, O_RDWR);
217 		vm_vcpu_add(vm, VCPU_ID);
218 		vcpu_set_cpuid(vm, VCPU_ID, kvm_get_supported_cpuid());
219 		vcpu_load_state(vm, VCPU_ID, state);
220 		run = vcpu_state(vm, VCPU_ID);
221 		free(state);
222 
223 		memset(&regs2, 0, sizeof(regs2));
224 		vcpu_regs_get(vm, VCPU_ID, &regs2);
225 		TEST_ASSERT(!memcmp(&regs1, &regs2, sizeof(regs2)),
226 			    "Unexpected register values after vcpu_load_state; rdi: %lx rsi: %lx",
227 			    (ulong) regs2.rdi, (ulong) regs2.rsi);
228 	}
229 
230 done:
231 	kvm_vm_free(vm);
232 }
233