selftests: kvm: add test for transferring FPU state into VMSA

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <20240404121327.3107131-18-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/tools/testing/selftests/kvm/x86_64/sev_smoke_test.c b/tools/testing/selftests/kvm/x86_64/sev_smoke_test.c
index 234c80dd344df9d1d354cae8c17ac04ed6989aa8..7c70c0da4fb7456087a4502b4e19c4442cd795f6 100644 (file)
--- a/tools/testing/selftests/kvm/x86_64/sev_smoke_test.c
+++ b/tools/testing/selftests/kvm/x86_64/sev_smoke_test.c
@@ -4,6 +4,7 @@
 #include <stdlib.h>
 #include <string.h>
 #include <sys/ioctl.h>
+#include <math.h>
 
 #include "test_util.h"
 #include "kvm_util.h"
@@ -13,6 +14,8 @@
 #include "sev.h"
 
 
+#define XFEATURE_MASK_X87_AVX (XFEATURE_MASK_FP | XFEATURE_MASK_SSE | XFEATURE_MASK_YMM)
+
 static void guest_sev_es_code(void)
 {
        /* TODO: Check CPUID after GHCB-based hypercall support is added. */
@@ -35,6 +38,86 @@ static void guest_sev_code(void)
        GUEST_DONE();
 }
 
+/* Stash state passed via VMSA before any compiled code runs.  */
+extern void guest_code_xsave(void);
+asm("guest_code_xsave:\n"
+    "mov $-1, %eax\n"
+    "mov $-1, %edx\n"
+    "xsave (%rdi)\n"
+    "jmp guest_sev_es_code");
+
+static void compare_xsave(u8 *from_host, u8 *from_guest)
+{
+       int i;
+       bool bad = false;
+       for (i = 0; i < 4095; i++) {
+               if (from_host[i] != from_guest[i]) {
+                       printf("mismatch at %02hhx | %02hhx %02hhx\n", i, from_host[i], from_guest[i]);
+                       bad = true;
+               }
+       }
+
+       if (bad)
+               abort();
+}
+
+static void test_sync_vmsa(uint32_t policy)
+{
+       struct kvm_vcpu *vcpu;
+       struct kvm_vm *vm;
+       vm_vaddr_t gva;
+       void *hva;
+
+       double x87val = M_PI;
+       struct kvm_xsave __attribute__((aligned(64))) xsave = { 0 };
+       struct kvm_sregs sregs;
+       struct kvm_xcrs xcrs = {
+               .nr_xcrs = 1,
+               .xcrs[0].xcr = 0,
+               .xcrs[0].value = XFEATURE_MASK_X87_AVX,
+       };
+
+       vm = vm_sev_create_with_one_vcpu(KVM_X86_SEV_ES_VM, guest_code_xsave, &vcpu);
+       gva = vm_vaddr_alloc_shared(vm, PAGE_SIZE, KVM_UTIL_MIN_VADDR,
+                                   MEM_REGION_TEST_DATA);
+       hva = addr_gva2hva(vm, gva);
+
+       vcpu_args_set(vcpu, 1, gva);
+
+       vcpu_sregs_get(vcpu, &sregs);
+       sregs.cr4 |= X86_CR4_OSFXSR | X86_CR4_OSXSAVE;
+       vcpu_sregs_set(vcpu, &sregs);
+
+       vcpu_xcrs_set(vcpu, &xcrs);
+       asm("fninit\n"
+           "vpcmpeqb %%ymm4, %%ymm4, %%ymm4\n"
+           "fldl %3\n"
+           "xsave (%2)\n"
+           "fstp %%st\n"
+           : "=m"(xsave)
+           : "A"(XFEATURE_MASK_X87_AVX), "r"(&xsave), "m" (x87val)
+           : "ymm4", "st", "st(1)", "st(2)", "st(3)", "st(4)", "st(5)", "st(6)", "st(7)");
+       vcpu_xsave_set(vcpu, &xsave);
+
+       vm_sev_launch(vm, SEV_POLICY_ES | policy, NULL);
+
+       /* This page is shared, so make it decrypted.  */
+       memset(hva, 0, 4096);
+
+       vcpu_run(vcpu);
+
+       TEST_ASSERT(vcpu->run->exit_reason == KVM_EXIT_SYSTEM_EVENT,
+                   "Wanted SYSTEM_EVENT, got %s",
+                   exit_reason_str(vcpu->run->exit_reason));
+       TEST_ASSERT_EQ(vcpu->run->system_event.type, KVM_SYSTEM_EVENT_SEV_TERM);
+       TEST_ASSERT_EQ(vcpu->run->system_event.ndata, 1);
+       TEST_ASSERT_EQ(vcpu->run->system_event.data[0], GHCB_MSR_TERM_REQ);
+
+       compare_xsave((u8 *)&xsave, (u8 *)hva);
+
+       kvm_vm_free(vm);
+}
+
 static void test_sev(void *guest_code, uint64_t policy)
 {
        struct kvm_vcpu *vcpu;
@@ -87,6 +170,12 @@ int main(int argc, char *argv[])
        if (kvm_cpu_has(X86_FEATURE_SEV_ES)) {
                test_sev(guest_sev_es_code, SEV_POLICY_ES | SEV_POLICY_NO_DBG);
                test_sev(guest_sev_es_code, SEV_POLICY_ES);
+
+               if (kvm_has_cap(KVM_CAP_XCRS) &&
+                   (xgetbv(0) & XFEATURE_MASK_X87_AVX) == XFEATURE_MASK_X87_AVX) {
+                       test_sync_vmsa(0);
+                       test_sync_vmsa(SEV_POLICY_NO_DBG);
+               }
        }
 
        return 0;