Commit 8c53183d authored by Paolo Bonzini's avatar Paolo Bonzini
Browse files

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



Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
Message-ID: <20240404121327.3107131-18-pbonzini@redhat.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 4c180a57

tools/testing/selftests/kvm/x86_64/sev_smoke_test.c

+89 −0
Original line number Diff line number Diff line
@@ -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;