xref: /linux/tools/testing/selftests/kvm/x86/sev_smoke_test.c (revision e78f70bad29c5ae1e1076698b690b15794e9b81e)
1 // SPDX-License-Identifier: GPL-2.0-only
2 #include <fcntl.h>
3 #include <stdio.h>
4 #include <stdlib.h>
5 #include <string.h>
6 #include <sys/ioctl.h>
7 #include <math.h>
8 
9 #include "test_util.h"
10 #include "kvm_util.h"
11 #include "processor.h"
12 #include "svm_util.h"
13 #include "linux/psp-sev.h"
14 #include "sev.h"
15 
16 
17 #define XFEATURE_MASK_X87_AVX (XFEATURE_MASK_FP | XFEATURE_MASK_SSE | XFEATURE_MASK_YMM)
18 
19 static void guest_snp_code(void)
20 {
21 	uint64_t sev_msr = rdmsr(MSR_AMD64_SEV);
22 
23 	GUEST_ASSERT(sev_msr & MSR_AMD64_SEV_ENABLED);
24 	GUEST_ASSERT(sev_msr & MSR_AMD64_SEV_ES_ENABLED);
25 	GUEST_ASSERT(sev_msr & MSR_AMD64_SEV_SNP_ENABLED);
26 
27 	wrmsr(MSR_AMD64_SEV_ES_GHCB, GHCB_MSR_TERM_REQ);
28 	vmgexit();
29 }
30 
31 static void guest_sev_es_code(void)
32 {
33 	/* TODO: Check CPUID after GHCB-based hypercall support is added. */
34 	GUEST_ASSERT(rdmsr(MSR_AMD64_SEV) & MSR_AMD64_SEV_ENABLED);
35 	GUEST_ASSERT(rdmsr(MSR_AMD64_SEV) & MSR_AMD64_SEV_ES_ENABLED);
36 
37 	/*
38 	 * TODO: Add GHCB and ucall support for SEV-ES guests.  For now, simply
39 	 * force "termination" to signal "done" via the GHCB MSR protocol.
40 	 */
41 	wrmsr(MSR_AMD64_SEV_ES_GHCB, GHCB_MSR_TERM_REQ);
42 	vmgexit();
43 }
44 
45 static void guest_sev_code(void)
46 {
47 	GUEST_ASSERT(this_cpu_has(X86_FEATURE_SEV));
48 	GUEST_ASSERT(rdmsr(MSR_AMD64_SEV) & MSR_AMD64_SEV_ENABLED);
49 
50 	GUEST_DONE();
51 }
52 
53 /* Stash state passed via VMSA before any compiled code runs.  */
54 extern void guest_code_xsave(void);
55 asm("guest_code_xsave:\n"
56     "mov $" __stringify(XFEATURE_MASK_X87_AVX) ", %eax\n"
57     "xor %edx, %edx\n"
58     "xsave (%rdi)\n"
59     "jmp guest_sev_es_code");
60 
61 static void compare_xsave(u8 *from_host, u8 *from_guest)
62 {
63 	int i;
64 	bool bad = false;
65 	for (i = 0; i < 4095; i++) {
66 		if (from_host[i] != from_guest[i]) {
67 			printf("mismatch at %u | %02hhx %02hhx\n",
68 			       i, from_host[i], from_guest[i]);
69 			bad = true;
70 		}
71 	}
72 
73 	if (bad)
74 		abort();
75 }
76 
77 static void test_sync_vmsa(uint32_t type, uint64_t policy)
78 {
79 	struct kvm_vcpu *vcpu;
80 	struct kvm_vm *vm;
81 	vm_vaddr_t gva;
82 	void *hva;
83 
84 	double x87val = M_PI;
85 	struct kvm_xsave __attribute__((aligned(64))) xsave = { 0 };
86 
87 	vm = vm_sev_create_with_one_vcpu(type, guest_code_xsave, &vcpu);
88 	gva = vm_vaddr_alloc_shared(vm, PAGE_SIZE, KVM_UTIL_MIN_VADDR,
89 				    MEM_REGION_TEST_DATA);
90 	hva = addr_gva2hva(vm, gva);
91 
92 	vcpu_args_set(vcpu, 1, gva);
93 
94 	asm("fninit\n"
95 	    "vpcmpeqb %%ymm4, %%ymm4, %%ymm4\n"
96 	    "fldl %3\n"
97 	    "xsave (%2)\n"
98 	    "fstp %%st\n"
99 	    : "=m"(xsave)
100 	    : "A"(XFEATURE_MASK_X87_AVX), "r"(&xsave), "m" (x87val)
101 	    : "ymm4", "st", "st(1)", "st(2)", "st(3)", "st(4)", "st(5)", "st(6)", "st(7)");
102 	vcpu_xsave_set(vcpu, &xsave);
103 
104 	vm_sev_launch(vm, policy, NULL);
105 
106 	/* This page is shared, so make it decrypted.  */
107 	memset(hva, 0, 4096);
108 
109 	vcpu_run(vcpu);
110 
111 	TEST_ASSERT(vcpu->run->exit_reason == KVM_EXIT_SYSTEM_EVENT,
112 		    "Wanted SYSTEM_EVENT, got %s",
113 		    exit_reason_str(vcpu->run->exit_reason));
114 	TEST_ASSERT_EQ(vcpu->run->system_event.type, KVM_SYSTEM_EVENT_SEV_TERM);
115 	TEST_ASSERT_EQ(vcpu->run->system_event.ndata, 1);
116 	TEST_ASSERT_EQ(vcpu->run->system_event.data[0], GHCB_MSR_TERM_REQ);
117 
118 	compare_xsave((u8 *)&xsave, (u8 *)hva);
119 
120 	kvm_vm_free(vm);
121 }
122 
123 static void test_sev(void *guest_code, uint32_t type, uint64_t policy)
124 {
125 	struct kvm_vcpu *vcpu;
126 	struct kvm_vm *vm;
127 	struct ucall uc;
128 
129 	vm = vm_sev_create_with_one_vcpu(type, guest_code, &vcpu);
130 
131 	/* TODO: Validate the measurement is as expected. */
132 	vm_sev_launch(vm, policy, NULL);
133 
134 	for (;;) {
135 		vcpu_run(vcpu);
136 
137 		if (is_sev_es_vm(vm)) {
138 			TEST_ASSERT(vcpu->run->exit_reason == KVM_EXIT_SYSTEM_EVENT,
139 				    "Wanted SYSTEM_EVENT, got %s",
140 				    exit_reason_str(vcpu->run->exit_reason));
141 			TEST_ASSERT_EQ(vcpu->run->system_event.type, KVM_SYSTEM_EVENT_SEV_TERM);
142 			TEST_ASSERT_EQ(vcpu->run->system_event.ndata, 1);
143 			TEST_ASSERT_EQ(vcpu->run->system_event.data[0], GHCB_MSR_TERM_REQ);
144 			break;
145 		}
146 
147 		switch (get_ucall(vcpu, &uc)) {
148 		case UCALL_SYNC:
149 			continue;
150 		case UCALL_DONE:
151 			return;
152 		case UCALL_ABORT:
153 			REPORT_GUEST_ASSERT(uc);
154 		default:
155 			TEST_FAIL("Unexpected exit: %s",
156 				  exit_reason_str(vcpu->run->exit_reason));
157 		}
158 	}
159 
160 	kvm_vm_free(vm);
161 }
162 
163 static void guest_shutdown_code(void)
164 {
165 	struct desc_ptr idt;
166 
167 	/* Clobber the IDT so that #UD is guaranteed to trigger SHUTDOWN. */
168 	memset(&idt, 0, sizeof(idt));
169 	set_idt(&idt);
170 
171 	__asm__ __volatile__("ud2");
172 }
173 
174 static void test_sev_shutdown(uint32_t type, uint64_t policy)
175 {
176 	struct kvm_vcpu *vcpu;
177 	struct kvm_vm *vm;
178 
179 	vm = vm_sev_create_with_one_vcpu(type, guest_shutdown_code, &vcpu);
180 
181 	vm_sev_launch(vm, policy, NULL);
182 
183 	vcpu_run(vcpu);
184 	TEST_ASSERT(vcpu->run->exit_reason == KVM_EXIT_SHUTDOWN,
185 		    "Wanted SHUTDOWN, got %s",
186 		    exit_reason_str(vcpu->run->exit_reason));
187 
188 	kvm_vm_free(vm);
189 }
190 
191 static void test_sev_smoke(void *guest, uint32_t type, uint64_t policy)
192 {
193 	const u64 xf_mask = XFEATURE_MASK_X87_AVX;
194 
195 	if (type == KVM_X86_SNP_VM)
196 		test_sev(guest, type, policy | SNP_POLICY_DBG);
197 	else
198 		test_sev(guest, type, policy | SEV_POLICY_NO_DBG);
199 	test_sev(guest, type, policy);
200 
201 	if (type == KVM_X86_SEV_VM)
202 		return;
203 
204 	test_sev_shutdown(type, policy);
205 
206 	if (kvm_has_cap(KVM_CAP_XCRS) &&
207 	    (xgetbv(0) & kvm_cpu_supported_xcr0() & xf_mask) == xf_mask) {
208 		test_sync_vmsa(type, policy);
209 		if (type == KVM_X86_SNP_VM)
210 			test_sync_vmsa(type, policy | SNP_POLICY_DBG);
211 		else
212 			test_sync_vmsa(type, policy | SEV_POLICY_NO_DBG);
213 	}
214 }
215 
216 int main(int argc, char *argv[])
217 {
218 	TEST_REQUIRE(kvm_cpu_has(X86_FEATURE_SEV));
219 
220 	test_sev_smoke(guest_sev_code, KVM_X86_SEV_VM, 0);
221 
222 	if (kvm_cpu_has(X86_FEATURE_SEV_ES))
223 		test_sev_smoke(guest_sev_es_code, KVM_X86_SEV_ES_VM, SEV_POLICY_ES);
224 
225 	if (kvm_cpu_has(X86_FEATURE_SEV_SNP))
226 		test_sev_smoke(guest_snp_code, KVM_X86_SNP_VM, snp_default_policy());
227 
228 	return 0;
229 }
230