1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (C) 2022, Red Hat, Inc.
4 *
5 * Tests for Hyper-V extensions to SVM.
6 */
7 #include <fcntl.h>
8 #include <stdio.h>
9 #include <stdlib.h>
10 #include <string.h>
11 #include <sys/ioctl.h>
12 #include <linux/bitmap.h>
13
14 #include "test_util.h"
15
16 #include "kvm_util.h"
17 #include "processor.h"
18 #include "svm_util.h"
19 #include "hyperv.h"
20
21 #define L2_GUEST_STACK_SIZE 256
22
23 /* Exit to L1 from L2 with RDMSR instruction */
24 static inline void rdmsr_from_l2(uint32_t msr)
25 {
26 /* Currently, L1 doesn't preserve GPRs during vmexits. */
27 __asm__ __volatile__ ("rdmsr" : : "c"(msr) :
28 "rax", "rbx", "rdx", "rsi", "rdi", "r8", "r9",
29 "r10", "r11", "r12", "r13", "r14", "r15");
30 }
31
32 void l2_guest_code(void)
33 {
34 u64 unused;
35
36 GUEST_SYNC(3);
37 /* Exit to L1 */
38 vmmcall();
39
40 /* MSR-Bitmap tests */
41 rdmsr_from_l2(MSR_FS_BASE); /* intercepted */
42 rdmsr_from_l2(MSR_FS_BASE); /* intercepted */
43 rdmsr_from_l2(MSR_GS_BASE); /* not intercepted */
44 vmmcall();
45 rdmsr_from_l2(MSR_GS_BASE); /* intercepted */
46
47 GUEST_SYNC(5);
48
49 /* L2 TLB flush tests */
50 hyperv_hypercall(HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE |
51 HV_HYPERCALL_FAST_BIT, 0x0,
52 HV_FLUSH_ALL_VIRTUAL_ADDRESS_SPACES |
53 HV_FLUSH_ALL_PROCESSORS);
54 rdmsr_from_l2(MSR_FS_BASE);
55 /*
56 * Note: hypercall status (RAX) is not preserved correctly by L1 after
57 * synthetic vmexit, use unchecked version.
58 */
59 __hyperv_hypercall(HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE |
60 HV_HYPERCALL_FAST_BIT, 0x0,
61 HV_FLUSH_ALL_VIRTUAL_ADDRESS_SPACES |
62 HV_FLUSH_ALL_PROCESSORS, &unused);
63
64 /* Done, exit to L1 and never come back. */
65 vmmcall();
66 }
67
68 static void __attribute__((__flatten__)) guest_code(struct svm_test_data *svm,
69 struct hyperv_test_pages *hv_pages,
70 vm_vaddr_t pgs_gpa)
71 {
72 unsigned long l2_guest_stack[L2_GUEST_STACK_SIZE];
73 struct vmcb *vmcb = svm->vmcb;
74 struct hv_vmcb_enlightenments *hve = &vmcb->control.hv_enlightenments;
75
76 GUEST_SYNC(1);
77
78 wrmsr(HV_X64_MSR_GUEST_OS_ID, HYPERV_LINUX_OS_ID);
79 wrmsr(HV_X64_MSR_HYPERCALL, pgs_gpa);
80 enable_vp_assist(hv_pages->vp_assist_gpa, hv_pages->vp_assist);
81
82 GUEST_ASSERT(svm->vmcb_gpa);
83 /* Prepare for L2 execution. */
84 generic_svm_setup(svm, l2_guest_code,
85 &l2_guest_stack[L2_GUEST_STACK_SIZE]);
86
87 /* L2 TLB flush setup */
88 hve->partition_assist_page = hv_pages->partition_assist_gpa;
89 hve->hv_enlightenments_control.nested_flush_hypercall = 1;
90 hve->hv_vm_id = 1;
91 hve->hv_vp_id = 1;
92 current_vp_assist->nested_control.features.directhypercall = 1;
93 *(u32 *)(hv_pages->partition_assist) = 0;
94
95 GUEST_SYNC(2);
96 run_guest(vmcb, svm->vmcb_gpa);
97 GUEST_ASSERT(vmcb->control.exit_code == SVM_EXIT_VMMCALL);
98 GUEST_SYNC(4);
99 vmcb->save.rip += 3;
100
101 /* Intercept RDMSR 0xc0000100 */
102 vmcb->control.intercept |= 1ULL << INTERCEPT_MSR_PROT;
103 __set_bit(2 * (MSR_FS_BASE & 0x1fff), svm->msr + 0x800);
104 run_guest(vmcb, svm->vmcb_gpa);
105 GUEST_ASSERT(vmcb->control.exit_code == SVM_EXIT_MSR);
106 vmcb->save.rip += 2; /* rdmsr */
107
108 /* Enable enlightened MSR bitmap */
109 hve->hv_enlightenments_control.msr_bitmap = 1;
110 run_guest(vmcb, svm->vmcb_gpa);
111 GUEST_ASSERT(vmcb->control.exit_code == SVM_EXIT_MSR);
112 vmcb->save.rip += 2; /* rdmsr */
113
114 /* Intercept RDMSR 0xc0000101 without telling KVM about it */
115 __set_bit(2 * (MSR_GS_BASE & 0x1fff), svm->msr + 0x800);
116 /* Make sure HV_VMX_ENLIGHTENED_CLEAN_FIELD_MSR_BITMAP is set */
117 vmcb->control.clean |= HV_VMCB_NESTED_ENLIGHTENMENTS;
118 run_guest(vmcb, svm->vmcb_gpa);
119 /* Make sure we don't see SVM_EXIT_MSR here so eMSR bitmap works */
120 GUEST_ASSERT(vmcb->control.exit_code == SVM_EXIT_VMMCALL);
121 vmcb->save.rip += 3; /* vmcall */
122
123 /* Now tell KVM we've changed MSR-Bitmap */
124 vmcb->control.clean &= ~HV_VMCB_NESTED_ENLIGHTENMENTS;
125 run_guest(vmcb, svm->vmcb_gpa);
126 GUEST_ASSERT(vmcb->control.exit_code == SVM_EXIT_MSR);
127 vmcb->save.rip += 2; /* rdmsr */
128
129
130 /*
131 * L2 TLB flush test. First VMCALL should be handled directly by L0,
132 * no VMCALL exit expected.
133 */
134 run_guest(vmcb, svm->vmcb_gpa);
135 GUEST_ASSERT(vmcb->control.exit_code == SVM_EXIT_MSR);
136 vmcb->save.rip += 2; /* rdmsr */
137 /* Enable synthetic vmexit */
138 *(u32 *)(hv_pages->partition_assist) = 1;
139 run_guest(vmcb, svm->vmcb_gpa);
140 GUEST_ASSERT(vmcb->control.exit_code == HV_SVM_EXITCODE_ENL);
141 GUEST_ASSERT(vmcb->control.exit_info_1 == HV_SVM_ENL_EXITCODE_TRAP_AFTER_FLUSH);
142
143 run_guest(vmcb, svm->vmcb_gpa);
144 GUEST_ASSERT(vmcb->control.exit_code == SVM_EXIT_VMMCALL);
145 GUEST_SYNC(6);
146
147 GUEST_DONE();
148 }
149
150 int main(int argc, char *argv[])
151 {
152 vm_vaddr_t nested_gva = 0, hv_pages_gva = 0;
153 vm_vaddr_t hcall_page;
154 struct kvm_vcpu *vcpu;
155 struct kvm_vm *vm;
156 struct ucall uc;
157 int stage;
158
159 TEST_REQUIRE(kvm_cpu_has(X86_FEATURE_SVM));
160 TEST_REQUIRE(kvm_has_cap(KVM_CAP_HYPERV_DIRECT_TLBFLUSH));
161
162 /* Create VM */
163 vm = vm_create_with_one_vcpu(&vcpu, guest_code);
164 vcpu_set_hv_cpuid(vcpu);
165 vcpu_alloc_svm(vm, &nested_gva);
166 vcpu_alloc_hyperv_test_pages(vm, &hv_pages_gva);
167
168 hcall_page = vm_vaddr_alloc_pages(vm, 1);
169 memset(addr_gva2hva(vm, hcall_page), 0x0, getpagesize());
170
171 vcpu_args_set(vcpu, 3, nested_gva, hv_pages_gva, addr_gva2gpa(vm, hcall_page));
172 vcpu_set_msr(vcpu, HV_X64_MSR_VP_INDEX, vcpu->id);
173
174 for (stage = 1;; stage++) {
175 vcpu_run(vcpu);
176 TEST_ASSERT_KVM_EXIT_REASON(vcpu, KVM_EXIT_IO);
177
178 switch (get_ucall(vcpu, &uc)) {
179 case UCALL_ABORT:
180 REPORT_GUEST_ASSERT(uc);
181 /* NOT REACHED */
182 case UCALL_SYNC:
183 break;
184 case UCALL_DONE:
185 goto done;
186 default:
187 TEST_FAIL("Unknown ucall %lu", uc.cmd);
188 }
189
190 /* UCALL_SYNC is handled here. */
191 TEST_ASSERT(!strcmp((const char *)uc.args[0], "hello") &&
192 uc.args[1] == stage, "Stage %d: Unexpected register values vmexit, got %lx",
193 stage, (ulong)uc.args[1]);
194
195 }
196
197 done:
198 kvm_vm_free(vm);
199 }
200
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.