xref: /linux/tools/testing/selftests/kvm/x86/sev_smoke_test.c (revision 11e8c7e9471cf8e6ae6ec7324a3174191cd965e3)
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 
guest_sev_test_msr(uint32_t msr)16 static void guest_sev_test_msr(uint32_t msr)
17 {
18 	uint64_t val = rdmsr(msr);
19 
20 	wrmsr(msr, val);
21 	GUEST_ASSERT(val == rdmsr(msr));
22 }
23 
24 #define guest_sev_test_reg(reg)			\
25 do {						\
26 	uint64_t val = get_##reg();		\
27 						\
28 	set_##reg(val);				\
29 	GUEST_ASSERT(val == get_##reg());	\
30 } while (0)
31 
guest_sev_test_regs(void)32 static void guest_sev_test_regs(void)
33 {
34 	guest_sev_test_msr(MSR_EFER);
35 	guest_sev_test_reg(cr0);
36 	guest_sev_test_reg(cr3);
37 	guest_sev_test_reg(cr4);
38 	guest_sev_test_reg(cr8);
39 }
40 
41 #define XFEATURE_MASK_X87_AVX (XFEATURE_MASK_FP | XFEATURE_MASK_SSE | XFEATURE_MASK_YMM)
42 
guest_snp_code(void)43 static void guest_snp_code(void)
44 {
45 	uint64_t sev_msr = rdmsr(MSR_AMD64_SEV);
46 
47 	GUEST_ASSERT(sev_msr & MSR_AMD64_SEV_ENABLED);
48 	GUEST_ASSERT(sev_msr & MSR_AMD64_SEV_ES_ENABLED);
49 	GUEST_ASSERT(sev_msr & MSR_AMD64_SEV_SNP_ENABLED);
50 
51 	guest_sev_test_regs();
52 
53 	wrmsr(MSR_AMD64_SEV_ES_GHCB, GHCB_MSR_TERM_REQ);
54 	vmgexit();
55 }
56 
guest_sev_es_code(void)57 static void guest_sev_es_code(void)
58 {
59 	/* TODO: Check CPUID after GHCB-based hypercall support is added. */
60 	GUEST_ASSERT(rdmsr(MSR_AMD64_SEV) & MSR_AMD64_SEV_ENABLED);
61 	GUEST_ASSERT(rdmsr(MSR_AMD64_SEV) & MSR_AMD64_SEV_ES_ENABLED);
62 
63 	guest_sev_test_regs();
64 
65 	/*
66 	 * TODO: Add GHCB and ucall support for SEV-ES guests.  For now, simply
67 	 * force "termination" to signal "done" via the GHCB MSR protocol.
68 	 */
69 	wrmsr(MSR_AMD64_SEV_ES_GHCB, GHCB_MSR_TERM_REQ);
70 	vmgexit();
71 }
72 
guest_sev_code(void)73 static void guest_sev_code(void)
74 {
75 	GUEST_ASSERT(this_cpu_has(X86_FEATURE_SEV));
76 	GUEST_ASSERT(rdmsr(MSR_AMD64_SEV) & MSR_AMD64_SEV_ENABLED);
77 
78 	guest_sev_test_regs();
79 
80 	GUEST_DONE();
81 }
82 
83 /* Stash state passed via VMSA before any compiled code runs.  */
84 extern void guest_code_xsave(void);
85 asm("guest_code_xsave:\n"
86     "mov $" __stringify(XFEATURE_MASK_X87_AVX) ", %eax\n"
87     "xor %edx, %edx\n"
88     "xsave (%rdi)\n"
89     "jmp guest_sev_es_code");
90 
compare_xsave(u8 * from_host,u8 * from_guest)91 static void compare_xsave(u8 *from_host, u8 *from_guest)
92 {
93 	int i;
94 	bool bad = false;
95 	for (i = 0; i < 4095; i++) {
96 		if (from_host[i] != from_guest[i]) {
97 			printf("mismatch at %u | %02hhx %02hhx\n",
98 			       i, from_host[i], from_guest[i]);
99 			bad = true;
100 		}
101 	}
102 
103 	if (bad)
104 		abort();
105 }
106 
test_sync_vmsa(uint32_t type,uint64_t policy)107 static void test_sync_vmsa(uint32_t type, uint64_t policy)
108 {
109 	struct kvm_vcpu *vcpu;
110 	struct kvm_vm *vm;
111 	vm_vaddr_t gva;
112 	void *hva;
113 
114 	double x87val = M_PI;
115 	struct kvm_xsave __attribute__((aligned(64))) xsave = { 0 };
116 
117 	vm = vm_sev_create_with_one_vcpu(type, guest_code_xsave, &vcpu);
118 	gva = vm_vaddr_alloc_shared(vm, PAGE_SIZE, KVM_UTIL_MIN_VADDR,
119 				    MEM_REGION_TEST_DATA);
120 	hva = addr_gva2hva(vm, gva);
121 
122 	vcpu_args_set(vcpu, 1, gva);
123 
124 	asm("fninit\n"
125 	    "vpcmpeqb %%ymm4, %%ymm4, %%ymm4\n"
126 	    "fldl %3\n"
127 	    "xsave (%2)\n"
128 	    "fstp %%st\n"
129 	    : "=m"(xsave)
130 	    : "A"(XFEATURE_MASK_X87_AVX), "r"(&xsave), "m" (x87val)
131 	    : "ymm4", "st", "st(1)", "st(2)", "st(3)", "st(4)", "st(5)", "st(6)", "st(7)");
132 	vcpu_xsave_set(vcpu, &xsave);
133 
134 	vm_sev_launch(vm, policy, NULL);
135 
136 	/* This page is shared, so make it decrypted.  */
137 	memset(hva, 0, PAGE_SIZE);
138 
139 	vcpu_run(vcpu);
140 
141 	TEST_ASSERT(vcpu->run->exit_reason == KVM_EXIT_SYSTEM_EVENT,
142 		    "Wanted SYSTEM_EVENT, got %s",
143 		    exit_reason_str(vcpu->run->exit_reason));
144 	TEST_ASSERT_EQ(vcpu->run->system_event.type, KVM_SYSTEM_EVENT_SEV_TERM);
145 	TEST_ASSERT_EQ(vcpu->run->system_event.ndata, 1);
146 	TEST_ASSERT_EQ(vcpu->run->system_event.data[0], GHCB_MSR_TERM_REQ);
147 
148 	compare_xsave((u8 *)&xsave, (u8 *)hva);
149 
150 	kvm_vm_free(vm);
151 }
152 
test_sev(void * guest_code,uint32_t type,uint64_t policy)153 static void test_sev(void *guest_code, uint32_t type, uint64_t policy)
154 {
155 	struct kvm_vcpu *vcpu;
156 	struct kvm_vm *vm;
157 	struct ucall uc;
158 
159 	vm = vm_sev_create_with_one_vcpu(type, guest_code, &vcpu);
160 
161 	/* TODO: Validate the measurement is as expected. */
162 	vm_sev_launch(vm, policy, NULL);
163 
164 	for (;;) {
165 		vcpu_run(vcpu);
166 
167 		if (is_sev_es_vm(vm)) {
168 			TEST_ASSERT(vcpu->run->exit_reason == KVM_EXIT_SYSTEM_EVENT,
169 				    "Wanted SYSTEM_EVENT, got %s",
170 				    exit_reason_str(vcpu->run->exit_reason));
171 			TEST_ASSERT_EQ(vcpu->run->system_event.type, KVM_SYSTEM_EVENT_SEV_TERM);
172 			TEST_ASSERT_EQ(vcpu->run->system_event.ndata, 1);
173 			TEST_ASSERT_EQ(vcpu->run->system_event.data[0], GHCB_MSR_TERM_REQ);
174 			break;
175 		}
176 
177 		switch (get_ucall(vcpu, &uc)) {
178 		case UCALL_SYNC:
179 			continue;
180 		case UCALL_DONE:
181 			return;
182 		case UCALL_ABORT:
183 			REPORT_GUEST_ASSERT(uc);
184 		default:
185 			TEST_FAIL("Unexpected exit: %s",
186 				  exit_reason_str(vcpu->run->exit_reason));
187 		}
188 	}
189 
190 	kvm_vm_free(vm);
191 }
192 
guest_shutdown_code(void)193 static void guest_shutdown_code(void)
194 {
195 	struct desc_ptr idt;
196 
197 	/* Clobber the IDT so that #UD is guaranteed to trigger SHUTDOWN. */
198 	memset(&idt, 0, sizeof(idt));
199 	set_idt(&idt);
200 
201 	__asm__ __volatile__("ud2");
202 }
203 
test_sev_shutdown(uint32_t type,uint64_t policy)204 static void test_sev_shutdown(uint32_t type, uint64_t policy)
205 {
206 	struct kvm_vcpu *vcpu;
207 	struct kvm_vm *vm;
208 
209 	vm = vm_sev_create_with_one_vcpu(type, guest_shutdown_code, &vcpu);
210 
211 	vm_sev_launch(vm, policy, NULL);
212 
213 	vcpu_run(vcpu);
214 	TEST_ASSERT(vcpu->run->exit_reason == KVM_EXIT_SHUTDOWN,
215 		    "Wanted SHUTDOWN, got %s",
216 		    exit_reason_str(vcpu->run->exit_reason));
217 
218 	kvm_vm_free(vm);
219 }
220 
test_sev_smoke(void * guest,uint32_t type,uint64_t policy)221 static void test_sev_smoke(void *guest, uint32_t type, uint64_t policy)
222 {
223 	const u64 xf_mask = XFEATURE_MASK_X87_AVX;
224 
225 	if (type == KVM_X86_SNP_VM)
226 		test_sev(guest, type, policy | SNP_POLICY_DBG);
227 	else
228 		test_sev(guest, type, policy | SEV_POLICY_NO_DBG);
229 	test_sev(guest, type, policy);
230 
231 	if (type == KVM_X86_SEV_VM)
232 		return;
233 
234 	test_sev_shutdown(type, policy);
235 
236 	if (kvm_has_cap(KVM_CAP_XCRS) &&
237 	    (xgetbv(0) & kvm_cpu_supported_xcr0() & xf_mask) == xf_mask) {
238 		test_sync_vmsa(type, policy);
239 		if (type == KVM_X86_SNP_VM)
240 			test_sync_vmsa(type, policy | SNP_POLICY_DBG);
241 		else
242 			test_sync_vmsa(type, policy | SEV_POLICY_NO_DBG);
243 	}
244 }
245 
main(int argc,char * argv[])246 int main(int argc, char *argv[])
247 {
248 	TEST_REQUIRE(kvm_cpu_has(X86_FEATURE_SEV));
249 
250 	test_sev_smoke(guest_sev_code, KVM_X86_SEV_VM, 0);
251 
252 	if (kvm_cpu_has(X86_FEATURE_SEV_ES))
253 		test_sev_smoke(guest_sev_es_code, KVM_X86_SEV_ES_VM, SEV_POLICY_ES);
254 
255 	if (kvm_cpu_has(X86_FEATURE_SEV_SNP))
256 		test_sev_smoke(guest_snp_code, KVM_X86_SNP_VM, snp_default_policy());
257 
258 	return 0;
259 }
260