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 /* Exit to L1 from L2 with RDMSR instruction */
rdmsr_from_l2(uint32_t msr)27 static inline void rdmsr_from_l2(uint32_t msr)
28 {
29 /* Currently, L1 doesn't preserve GPRs during vmexits. */
30 __asm__ __volatile__ ("rdmsr" : : "c"(msr) :
31 "rax", "rbx", "rdx", "rsi", "rdi", "r8", "r9",
32 "r10", "r11", "r12", "r13", "r14", "r15");
33 }
34
l2_guest_code(void)35 void l2_guest_code(void)
36 {
37 u64 unused;
38
39 GUEST_SYNC(3);
40 /* Exit to L1 */
41 vmmcall();
42
43 /* MSR-Bitmap tests */
44 rdmsr_from_l2(MSR_FS_BASE); /* intercepted */
45 rdmsr_from_l2(MSR_FS_BASE); /* intercepted */
46 rdmsr_from_l2(MSR_GS_BASE); /* not intercepted */
47 vmmcall();
48 rdmsr_from_l2(MSR_GS_BASE); /* intercepted */
49
50 GUEST_SYNC(5);
51
52 /* L2 TLB flush tests */
53 hyperv_hypercall(HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE |
54 HV_HYPERCALL_FAST_BIT, 0x0,
55 HV_FLUSH_ALL_VIRTUAL_ADDRESS_SPACES |
56 HV_FLUSH_ALL_PROCESSORS);
57 rdmsr_from_l2(MSR_FS_BASE);
58 /*
59 * Note: hypercall status (RAX) is not preserved correctly by L1 after
60 * synthetic vmexit, use unchecked version.
61 */
62 __hyperv_hypercall(HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE |
63 HV_HYPERCALL_FAST_BIT, 0x0,
64 HV_FLUSH_ALL_VIRTUAL_ADDRESS_SPACES |
65 HV_FLUSH_ALL_PROCESSORS, &unused);
66
67 /* Done, exit to L1 and never come back. */
68 vmmcall();
69 }
70
guest_code(struct svm_test_data * svm,struct hyperv_test_pages * hv_pages,vm_vaddr_t pgs_gpa)71 static void __attribute__((__flatten__)) guest_code(struct svm_test_data *svm,
72 struct hyperv_test_pages *hv_pages,
73 vm_vaddr_t pgs_gpa)
74 {
75 unsigned long l2_guest_stack[L2_GUEST_STACK_SIZE];
76 struct vmcb *vmcb = svm->vmcb;
77 struct hv_vmcb_enlightenments *hve = &vmcb->control.hv_enlightenments;
78
79 GUEST_SYNC(1);
80
81 wrmsr(HV_X64_MSR_GUEST_OS_ID, HYPERV_LINUX_OS_ID);
82 wrmsr(HV_X64_MSR_HYPERCALL, pgs_gpa);
83 enable_vp_assist(hv_pages->vp_assist_gpa, hv_pages->vp_assist);
84
85 GUEST_ASSERT(svm->vmcb_gpa);
86 /* Prepare for L2 execution. */
87 generic_svm_setup(svm, l2_guest_code,
88 &l2_guest_stack[L2_GUEST_STACK_SIZE]);
89
90 /* L2 TLB flush setup */
91 hve->partition_assist_page = hv_pages->partition_assist_gpa;
92 hve->hv_enlightenments_control.nested_flush_hypercall = 1;
93 hve->hv_vm_id = 1;
94 hve->hv_vp_id = 1;
95 current_vp_assist->nested_control.features.directhypercall = 1;
96 *(u32 *)(hv_pages->partition_assist) = 0;
97
98 GUEST_SYNC(2);
99 run_guest(vmcb, svm->vmcb_gpa);
100 GUEST_ASSERT(vmcb->control.exit_code == SVM_EXIT_VMMCALL);
101 GUEST_SYNC(4);
102 vmcb->save.rip += 3;
103
104 /* Intercept RDMSR 0xc0000100 */
105 vmcb->control.intercept |= 1ULL << INTERCEPT_MSR_PROT;
106 __set_bit(2 * (MSR_FS_BASE & 0x1fff), svm->msr + 0x800);
107 run_guest(vmcb, svm->vmcb_gpa);
108 GUEST_ASSERT(vmcb->control.exit_code == SVM_EXIT_MSR);
109 vmcb->save.rip += 2; /* rdmsr */
110
111 /* Enable enlightened MSR bitmap */
112 hve->hv_enlightenments_control.msr_bitmap = 1;
113 run_guest(vmcb, svm->vmcb_gpa);
114 GUEST_ASSERT(vmcb->control.exit_code == SVM_EXIT_MSR);
115 vmcb->save.rip += 2; /* rdmsr */
116
117 /* Intercept RDMSR 0xc0000101 without telling KVM about it */
118 __set_bit(2 * (MSR_GS_BASE & 0x1fff), svm->msr + 0x800);
119 /* Make sure HV_VMX_ENLIGHTENED_CLEAN_FIELD_MSR_BITMAP is set */
120 vmcb->control.clean |= HV_VMCB_NESTED_ENLIGHTENMENTS;
121 run_guest(vmcb, svm->vmcb_gpa);
122 /* Make sure we don't see SVM_EXIT_MSR here so eMSR bitmap works */
123 GUEST_ASSERT(vmcb->control.exit_code == SVM_EXIT_VMMCALL);
124 vmcb->save.rip += 3; /* vmcall */
125
126 /* Now tell KVM we've changed MSR-Bitmap */
127 vmcb->control.clean &= ~HV_VMCB_NESTED_ENLIGHTENMENTS;
128 run_guest(vmcb, svm->vmcb_gpa);
129 GUEST_ASSERT(vmcb->control.exit_code == SVM_EXIT_MSR);
130 vmcb->save.rip += 2; /* rdmsr */
131
132
133 /*
134 * L2 TLB flush test. First VMCALL should be handled directly by L0,
135 * no VMCALL exit expected.
136 */
137 run_guest(vmcb, svm->vmcb_gpa);
138 GUEST_ASSERT(vmcb->control.exit_code == SVM_EXIT_MSR);
139 vmcb->save.rip += 2; /* rdmsr */
140 /* Enable synthetic vmexit */
141 *(u32 *)(hv_pages->partition_assist) = 1;
142 run_guest(vmcb, svm->vmcb_gpa);
143 GUEST_ASSERT(vmcb->control.exit_code == HV_SVM_EXITCODE_ENL);
144 GUEST_ASSERT(vmcb->control.exit_info_1 == HV_SVM_ENL_EXITCODE_TRAP_AFTER_FLUSH);
145
146 run_guest(vmcb, svm->vmcb_gpa);
147 GUEST_ASSERT(vmcb->control.exit_code == SVM_EXIT_VMMCALL);
148 GUEST_SYNC(6);
149
150 GUEST_DONE();
151 }
152
main(int argc,char * argv[])153 int main(int argc, char *argv[])
154 {
155 vm_vaddr_t nested_gva = 0, hv_pages_gva = 0;
156 vm_vaddr_t hcall_page;
157 struct kvm_vcpu *vcpu;
158 struct kvm_vm *vm;
159 struct kvm_run *run;
160 struct ucall uc;
161 int stage;
162
163 TEST_REQUIRE(kvm_cpu_has(X86_FEATURE_SVM));
164
165 /* Create VM */
166 vm = vm_create_with_one_vcpu(&vcpu, guest_code);
167 vcpu_set_hv_cpuid(vcpu);
168 run = vcpu->run;
169 vcpu_alloc_svm(vm, &nested_gva);
170 vcpu_alloc_hyperv_test_pages(vm, &hv_pages_gva);
171
172 hcall_page = vm_vaddr_alloc_pages(vm, 1);
173 memset(addr_gva2hva(vm, hcall_page), 0x0, getpagesize());
174
175 vcpu_args_set(vcpu, 3, nested_gva, hv_pages_gva, addr_gva2gpa(vm, hcall_page));
176 vcpu_set_msr(vcpu, HV_X64_MSR_VP_INDEX, vcpu->id);
177
178 for (stage = 1;; stage++) {
179 vcpu_run(vcpu);
180 TEST_ASSERT(run->exit_reason == KVM_EXIT_IO,
181 "Stage %d: unexpected exit reason: %u (%s),\n",
182 stage, run->exit_reason,
183 exit_reason_str(run->exit_reason));
184
185 switch (get_ucall(vcpu, &uc)) {
186 case UCALL_ABORT:
187 REPORT_GUEST_ASSERT(uc);
188 /* NOT REACHED */
189 case UCALL_SYNC:
190 break;
191 case UCALL_DONE:
192 goto done;
193 default:
194 TEST_FAIL("Unknown ucall %lu", uc.cmd);
195 }
196
197 /* UCALL_SYNC is handled here. */
198 TEST_ASSERT(!strcmp((const char *)uc.args[0], "hello") &&
199 uc.args[1] == stage, "Stage %d: Unexpected register values vmexit, got %lx",
200 stage, (ulong)uc.args[1]);
201
202 }
203
204 done:
205 kvm_vm_free(vm);
206 }
207