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 L2_GUEST_STACK_SIZE 256
25
26 struct hv_enlightenments {
27 struct __packed hv_enlightenments_control {
28 u32 nested_flush_hypercall:1;
29 u32 msr_bitmap:1;
30 u32 enlightened_npt_tlb: 1;
31 u32 reserved:29;
32 } __packed hv_enlightenments_control;
33 u32 hv_vp_id;
34 u64 hv_vm_id;
35 u64 partition_assist_page;
36 u64 reserved;
37 } __packed;
38
39 /*
40 * Hyper-V uses the software reserved clean bit in VMCB
41 */
42 #define VMCB_HV_NESTED_ENLIGHTENMENTS (1U << 31)
43
l2_guest_code(void)44 void l2_guest_code(void)
45 {
46 GUEST_SYNC(3);
47 /* Exit to L1 */
48 vmmcall();
49
50 /* MSR-Bitmap tests */
51 rdmsr(MSR_FS_BASE); /* intercepted */
52 rdmsr(MSR_FS_BASE); /* intercepted */
53 rdmsr(MSR_GS_BASE); /* not intercepted */
54 vmmcall();
55 rdmsr(MSR_GS_BASE); /* intercepted */
56
57 GUEST_SYNC(5);
58
59 /* Done, exit to L1 and never come back. */
60 vmmcall();
61 }
62
guest_code(struct svm_test_data * svm)63 static void __attribute__((__flatten__)) guest_code(struct svm_test_data *svm)
64 {
65 unsigned long l2_guest_stack[L2_GUEST_STACK_SIZE];
66 struct vmcb *vmcb = svm->vmcb;
67 struct hv_enlightenments *hve =
68 (struct hv_enlightenments *)vmcb->control.reserved_sw;
69
70 GUEST_SYNC(1);
71
72 wrmsr(HV_X64_MSR_GUEST_OS_ID, (u64)0x8100 << 48);
73
74 GUEST_ASSERT(svm->vmcb_gpa);
75 /* Prepare for L2 execution. */
76 generic_svm_setup(svm, l2_guest_code,
77 &l2_guest_stack[L2_GUEST_STACK_SIZE]);
78
79 GUEST_SYNC(2);
80 run_guest(vmcb, svm->vmcb_gpa);
81 GUEST_ASSERT(vmcb->control.exit_code == SVM_EXIT_VMMCALL);
82 GUEST_SYNC(4);
83 vmcb->save.rip += 3;
84
85 /* Intercept RDMSR 0xc0000100 */
86 vmcb->control.intercept |= 1ULL << INTERCEPT_MSR_PROT;
87 set_bit(2 * (MSR_FS_BASE & 0x1fff), svm->msr + 0x800);
88 run_guest(vmcb, svm->vmcb_gpa);
89 GUEST_ASSERT(vmcb->control.exit_code == SVM_EXIT_MSR);
90 vmcb->save.rip += 2; /* rdmsr */
91
92 /* Enable enlightened MSR bitmap */
93 hve->hv_enlightenments_control.msr_bitmap = 1;
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 /* Intercept RDMSR 0xc0000101 without telling KVM about it */
99 set_bit(2 * (MSR_GS_BASE & 0x1fff), svm->msr + 0x800);
100 /* Make sure HV_VMX_ENLIGHTENED_CLEAN_FIELD_MSR_BITMAP is set */
101 vmcb->control.clean |= VMCB_HV_NESTED_ENLIGHTENMENTS;
102 run_guest(vmcb, svm->vmcb_gpa);
103 /* Make sure we don't see SVM_EXIT_MSR here so eMSR bitmap works */
104 GUEST_ASSERT(vmcb->control.exit_code == SVM_EXIT_VMMCALL);
105 vmcb->save.rip += 3; /* vmcall */
106
107 /* Now tell KVM we've changed MSR-Bitmap */
108 vmcb->control.clean &= ~VMCB_HV_NESTED_ENLIGHTENMENTS;
109 run_guest(vmcb, svm->vmcb_gpa);
110 GUEST_ASSERT(vmcb->control.exit_code == SVM_EXIT_MSR);
111 vmcb->save.rip += 2; /* rdmsr */
112
113 run_guest(vmcb, svm->vmcb_gpa);
114 GUEST_ASSERT(vmcb->control.exit_code == SVM_EXIT_VMMCALL);
115 GUEST_SYNC(6);
116
117 GUEST_DONE();
118 }
119
main(int argc,char * argv[])120 int main(int argc, char *argv[])
121 {
122 vm_vaddr_t nested_gva = 0;
123
124 struct kvm_vcpu *vcpu;
125 struct kvm_vm *vm;
126 struct kvm_run *run;
127 struct ucall uc;
128 int stage;
129
130 TEST_REQUIRE(kvm_cpu_has(X86_FEATURE_SVM));
131
132 /* Create VM */
133 vm = vm_create_with_one_vcpu(&vcpu, guest_code);
134 vcpu_set_hv_cpuid(vcpu);
135 run = vcpu->run;
136 vcpu_alloc_svm(vm, &nested_gva);
137 vcpu_args_set(vcpu, 1, nested_gva);
138
139 for (stage = 1;; stage++) {
140 vcpu_run(vcpu);
141 TEST_ASSERT(run->exit_reason == KVM_EXIT_IO,
142 "Stage %d: unexpected exit reason: %u (%s),\n",
143 stage, run->exit_reason,
144 exit_reason_str(run->exit_reason));
145
146 switch (get_ucall(vcpu, &uc)) {
147 case UCALL_ABORT:
148 REPORT_GUEST_ASSERT(uc);
149 /* NOT REACHED */
150 case UCALL_SYNC:
151 break;
152 case UCALL_DONE:
153 goto done;
154 default:
155 TEST_FAIL("Unknown ucall %lu", uc.cmd);
156 }
157
158 /* UCALL_SYNC is handled here. */
159 TEST_ASSERT(!strcmp((const char *)uc.args[0], "hello") &&
160 uc.args[1] == stage, "Stage %d: Unexpected register values vmexit, got %lx",
161 stage, (ulong)uc.args[1]);
162
163 }
164
165 done:
166 kvm_vm_free(vm);
167 }
168