1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright (C) 2018, Red Hat, Inc.
4 *
5 * Tests for Enlightened VMCS, including nested guest state.
6 */
7 #define _GNU_SOURCE /* for program_invocation_short_name */
8 #include <fcntl.h>
9 #include <stdio.h>
10 #include <stdlib.h>
11 #include <string.h>
12 #include <sys/ioctl.h>
13
14 #include "test_util.h"
15
16 #include "kvm_util.h"
17
18 #include "vmx.h"
19
20 #define VCPU_ID 5
21 #define NMI_VECTOR 2
22
23 static int ud_count;
24
guest_ud_handler(struct ex_regs * regs)25 static void guest_ud_handler(struct ex_regs *regs)
26 {
27 ud_count++;
28 regs->rip += 3; /* VMLAUNCH */
29 }
30
guest_nmi_handler(struct ex_regs * regs)31 static void guest_nmi_handler(struct ex_regs *regs)
32 {
33 }
34
l2_guest_code(void)35 void l2_guest_code(void)
36 {
37 GUEST_SYNC(7);
38
39 GUEST_SYNC(8);
40
41 /* Forced exit to L1 upon restore */
42 GUEST_SYNC(9);
43
44 /* Done, exit to L1 and never come back. */
45 vmcall();
46 }
47
guest_code(struct vmx_pages * vmx_pages)48 void guest_code(struct vmx_pages *vmx_pages)
49 {
50 #define L2_GUEST_STACK_SIZE 64
51 unsigned long l2_guest_stack[L2_GUEST_STACK_SIZE];
52
53 x2apic_enable();
54
55 GUEST_SYNC(1);
56 GUEST_SYNC(2);
57
58 enable_vp_assist(vmx_pages->vp_assist_gpa, vmx_pages->vp_assist);
59
60 GUEST_ASSERT(vmx_pages->vmcs_gpa);
61 GUEST_ASSERT(prepare_for_vmx_operation(vmx_pages));
62 GUEST_SYNC(3);
63 GUEST_ASSERT(load_vmcs(vmx_pages));
64 GUEST_ASSERT(vmptrstz() == vmx_pages->enlightened_vmcs_gpa);
65
66 GUEST_SYNC(4);
67 GUEST_ASSERT(vmptrstz() == vmx_pages->enlightened_vmcs_gpa);
68
69 prepare_vmcs(vmx_pages, l2_guest_code,
70 &l2_guest_stack[L2_GUEST_STACK_SIZE]);
71
72 GUEST_SYNC(5);
73 GUEST_ASSERT(vmptrstz() == vmx_pages->enlightened_vmcs_gpa);
74 current_evmcs->revision_id = -1u;
75 GUEST_ASSERT(vmlaunch());
76 current_evmcs->revision_id = EVMCS_VERSION;
77 GUEST_SYNC(6);
78
79 current_evmcs->pin_based_vm_exec_control |=
80 PIN_BASED_NMI_EXITING;
81 GUEST_ASSERT(!vmlaunch());
82 GUEST_ASSERT(vmptrstz() == vmx_pages->enlightened_vmcs_gpa);
83
84 /*
85 * NMI forces L2->L1 exit, resuming L2 and hope that EVMCS is
86 * up-to-date (RIP points where it should and not at the beginning
87 * of l2_guest_code(). GUEST_SYNC(9) checkes that.
88 */
89 GUEST_ASSERT(!vmresume());
90
91 GUEST_SYNC(10);
92
93 GUEST_ASSERT(vmreadz(VM_EXIT_REASON) == EXIT_REASON_VMCALL);
94 GUEST_SYNC(11);
95
96 /* Try enlightened vmptrld with an incorrect GPA */
97 evmcs_vmptrld(0xdeadbeef, vmx_pages->enlightened_vmcs);
98 GUEST_ASSERT(vmlaunch());
99 GUEST_ASSERT(ud_count == 1);
100 GUEST_DONE();
101 }
102
inject_nmi(struct kvm_vm * vm)103 void inject_nmi(struct kvm_vm *vm)
104 {
105 struct kvm_vcpu_events events;
106
107 vcpu_events_get(vm, VCPU_ID, &events);
108
109 events.nmi.pending = 1;
110 events.flags |= KVM_VCPUEVENT_VALID_NMI_PENDING;
111
112 vcpu_events_set(vm, VCPU_ID, &events);
113 }
114
save_restore_vm(struct kvm_vm * vm)115 static void save_restore_vm(struct kvm_vm *vm)
116 {
117 struct kvm_regs regs1, regs2;
118 struct kvm_x86_state *state;
119
120 state = vcpu_save_state(vm, VCPU_ID);
121 memset(®s1, 0, sizeof(regs1));
122 vcpu_regs_get(vm, VCPU_ID, ®s1);
123
124 kvm_vm_release(vm);
125
126 /* Restore state in a new VM. */
127 kvm_vm_restart(vm, O_RDWR);
128 vm_vcpu_add(vm, VCPU_ID);
129 vcpu_set_hv_cpuid(vm, VCPU_ID);
130 vcpu_enable_evmcs(vm, VCPU_ID);
131 vcpu_load_state(vm, VCPU_ID, state);
132 free(state);
133
134 memset(®s2, 0, sizeof(regs2));
135 vcpu_regs_get(vm, VCPU_ID, ®s2);
136 TEST_ASSERT(!memcmp(®s1, ®s2, sizeof(regs2)),
137 "Unexpected register values after vcpu_load_state; rdi: %lx rsi: %lx",
138 (ulong) regs2.rdi, (ulong) regs2.rsi);
139 }
140
main(int argc,char * argv[])141 int main(int argc, char *argv[])
142 {
143 vm_vaddr_t vmx_pages_gva = 0;
144
145 struct kvm_vm *vm;
146 struct kvm_run *run;
147 struct ucall uc;
148 int stage;
149
150 /* Create VM */
151 vm = vm_create_default(VCPU_ID, 0, guest_code);
152
153 if (!nested_vmx_supported() ||
154 !kvm_check_cap(KVM_CAP_NESTED_STATE) ||
155 !kvm_check_cap(KVM_CAP_HYPERV_ENLIGHTENED_VMCS)) {
156 print_skip("Enlightened VMCS is unsupported");
157 exit(KSFT_SKIP);
158 }
159
160 vcpu_set_hv_cpuid(vm, VCPU_ID);
161 vcpu_enable_evmcs(vm, VCPU_ID);
162
163 vcpu_alloc_vmx(vm, &vmx_pages_gva);
164 vcpu_args_set(vm, VCPU_ID, 1, vmx_pages_gva);
165
166 vm_init_descriptor_tables(vm);
167 vcpu_init_descriptor_tables(vm, VCPU_ID);
168 vm_install_exception_handler(vm, UD_VECTOR, guest_ud_handler);
169 vm_install_exception_handler(vm, NMI_VECTOR, guest_nmi_handler);
170
171 pr_info("Running L1 which uses EVMCS to run L2\n");
172
173 for (stage = 1;; stage++) {
174 run = vcpu_state(vm, VCPU_ID);
175 _vcpu_run(vm, VCPU_ID);
176 TEST_ASSERT(run->exit_reason == KVM_EXIT_IO,
177 "Stage %d: unexpected exit reason: %u (%s),\n",
178 stage, run->exit_reason,
179 exit_reason_str(run->exit_reason));
180
181 switch (get_ucall(vm, VCPU_ID, &uc)) {
182 case UCALL_ABORT:
183 TEST_FAIL("%s at %s:%ld", (const char *)uc.args[0],
184 __FILE__, uc.args[1]);
185 /* NOT REACHED */
186 case UCALL_SYNC:
187 break;
188 case UCALL_DONE:
189 goto done;
190 default:
191 TEST_FAIL("Unknown ucall %lu", uc.cmd);
192 }
193
194 /* UCALL_SYNC is handled here. */
195 TEST_ASSERT(!strcmp((const char *)uc.args[0], "hello") &&
196 uc.args[1] == stage, "Stage %d: Unexpected register values vmexit, got %lx",
197 stage, (ulong)uc.args[1]);
198
199 save_restore_vm(vm);
200
201 /* Force immediate L2->L1 exit before resuming */
202 if (stage == 8) {
203 pr_info("Injecting NMI into L1 before L2 had a chance to run after restore\n");
204 inject_nmi(vm);
205 }
206
207 /*
208 * Do KVM_GET_NESTED_STATE/KVM_SET_NESTED_STATE for a freshly
209 * restored VM (before the first KVM_RUN) to check that
210 * KVM_STATE_NESTED_EVMCS is not lost.
211 */
212 if (stage == 9) {
213 pr_info("Trying extra KVM_GET_NESTED_STATE/KVM_SET_NESTED_STATE cycle\n");
214 save_restore_vm(vm);
215 }
216 }
217
218 done:
219 kvm_vm_free(vm);
220 }
221