1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * KVM_GET/SET_* tests
4 *
5 * Copyright (C) 2022, Red Hat, Inc.
6 *
7 * Tests for Hyper-V extensions to SVM.
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 #include <linux/bitmap.h>
16
17 #include "test_util.h"
18
19 #include "kvm_util.h"
20 #include "processor.h"
21 #include "svm_util.h"
22 #include "hyperv.h"
23
24 #define VCPU_ID 1
25 #define L2_GUEST_STACK_SIZE 256
26
27 struct hv_enlightenments {
28 struct __packed hv_enlightenments_control {
29 u32 nested_flush_hypercall:1;
30 u32 msr_bitmap:1;
31 u32 enlightened_npt_tlb: 1;
32 u32 reserved:29;
33 } __packed hv_enlightenments_control;
34 u32 hv_vp_id;
35 u64 hv_vm_id;
36 u64 partition_assist_page;
37 u64 reserved;
38 } __packed;
39
40 /*
41 * Hyper-V uses the software reserved clean bit in VMCB
42 */
43 #define VMCB_HV_NESTED_ENLIGHTENMENTS (1U << 31)
44
vmmcall(void)45 static inline void vmmcall(void)
46 {
47 __asm__ __volatile__("vmmcall");
48 }
49
l2_guest_code(void)50 void l2_guest_code(void)
51 {
52 GUEST_SYNC(3);
53 /* Exit to L1 */
54 vmmcall();
55
56 /* MSR-Bitmap tests */
57 rdmsr(MSR_FS_BASE); /* intercepted */
58 rdmsr(MSR_FS_BASE); /* intercepted */
59 rdmsr(MSR_GS_BASE); /* not intercepted */
60 vmmcall();
61 rdmsr(MSR_GS_BASE); /* intercepted */
62
63 GUEST_SYNC(5);
64
65 /* Done, exit to L1 and never come back. */
66 vmmcall();
67 }
68
guest_code(struct svm_test_data * svm)69 static void __attribute__((__flatten__)) guest_code(struct svm_test_data *svm)
70 {
71 unsigned long l2_guest_stack[L2_GUEST_STACK_SIZE];
72 struct vmcb *vmcb = svm->vmcb;
73 struct hv_enlightenments *hve =
74 (struct hv_enlightenments *)vmcb->control.reserved_sw;
75
76 GUEST_SYNC(1);
77
78 wrmsr(HV_X64_MSR_GUEST_OS_ID, (u64)0x8100 << 48);
79
80 GUEST_ASSERT(svm->vmcb_gpa);
81 /* Prepare for L2 execution. */
82 generic_svm_setup(svm, l2_guest_code,
83 &l2_guest_stack[L2_GUEST_STACK_SIZE]);
84
85 GUEST_SYNC(2);
86 run_guest(vmcb, svm->vmcb_gpa);
87 GUEST_ASSERT(vmcb->control.exit_code == SVM_EXIT_VMMCALL);
88 GUEST_SYNC(4);
89 vmcb->save.rip += 3;
90
91 /* Intercept RDMSR 0xc0000100 */
92 vmcb->control.intercept |= 1ULL << INTERCEPT_MSR_PROT;
93 set_bit(2 * (MSR_FS_BASE & 0x1fff), svm->msr + 0x800);
94 run_guest(vmcb, svm->vmcb_gpa);
95 GUEST_ASSERT(vmcb->control.exit_code == SVM_EXIT_MSR);
96 vmcb->save.rip += 2; /* rdmsr */
97
98 /* Enable enlightened MSR bitmap */
99 hve->hv_enlightenments_control.msr_bitmap = 1;
100 run_guest(vmcb, svm->vmcb_gpa);
101 GUEST_ASSERT(vmcb->control.exit_code == SVM_EXIT_MSR);
102 vmcb->save.rip += 2; /* rdmsr */
103
104 /* Intercept RDMSR 0xc0000101 without telling KVM about it */
105 set_bit(2 * (MSR_GS_BASE & 0x1fff), svm->msr + 0x800);
106 /* Make sure HV_VMX_ENLIGHTENED_CLEAN_FIELD_MSR_BITMAP is set */
107 vmcb->control.clean |= VMCB_HV_NESTED_ENLIGHTENMENTS;
108 run_guest(vmcb, svm->vmcb_gpa);
109 /* Make sure we don't see SVM_EXIT_MSR here so eMSR bitmap works */
110 GUEST_ASSERT(vmcb->control.exit_code == SVM_EXIT_VMMCALL);
111 vmcb->save.rip += 3; /* vmcall */
112
113 /* Now tell KVM we've changed MSR-Bitmap */
114 vmcb->control.clean &= ~VMCB_HV_NESTED_ENLIGHTENMENTS;
115 run_guest(vmcb, svm->vmcb_gpa);
116 GUEST_ASSERT(vmcb->control.exit_code == SVM_EXIT_MSR);
117 vmcb->save.rip += 2; /* rdmsr */
118
119 run_guest(vmcb, svm->vmcb_gpa);
120 GUEST_ASSERT(vmcb->control.exit_code == SVM_EXIT_VMMCALL);
121 GUEST_SYNC(6);
122
123 GUEST_DONE();
124 }
125
main(int argc,char * argv[])126 int main(int argc, char *argv[])
127 {
128 vm_vaddr_t nested_gva = 0;
129
130 struct kvm_vm *vm;
131 struct kvm_run *run;
132 struct ucall uc;
133 int stage;
134
135 if (!nested_svm_supported()) {
136 print_skip("Nested SVM not supported");
137 exit(KSFT_SKIP);
138 }
139 /* Create VM */
140 vm = vm_create_default(VCPU_ID, 0, guest_code);
141 vcpu_set_hv_cpuid(vm, VCPU_ID);
142 run = vcpu_state(vm, VCPU_ID);
143 vcpu_alloc_svm(vm, &nested_gva);
144 vcpu_args_set(vm, VCPU_ID, 1, nested_gva);
145
146 for (stage = 1;; stage++) {
147 _vcpu_run(vm, VCPU_ID);
148 TEST_ASSERT(run->exit_reason == KVM_EXIT_IO,
149 "Stage %d: unexpected exit reason: %u (%s),\n",
150 stage, run->exit_reason,
151 exit_reason_str(run->exit_reason));
152
153 switch (get_ucall(vm, VCPU_ID, &uc)) {
154 case UCALL_ABORT:
155 TEST_FAIL("%s at %s:%ld", (const char *)uc.args[0],
156 __FILE__, uc.args[1]);
157 /* NOT REACHED */
158 case UCALL_SYNC:
159 break;
160 case UCALL_DONE:
161 goto done;
162 default:
163 TEST_FAIL("Unknown ucall %lu", uc.cmd);
164 }
165
166 /* UCALL_SYNC is handled here. */
167 TEST_ASSERT(!strcmp((const char *)uc.args[0], "hello") &&
168 uc.args[1] == stage, "Stage %d: Unexpected register values vmexit, got %lx",
169 stage, (ulong)uc.args[1]);
170
171 }
172
173 done:
174 kvm_vm_free(vm);
175 }
176