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-rw-r--r--tools/testing/selftests/kvm/x86_64/state_test.c154
1 files changed, 125 insertions, 29 deletions
diff --git a/tools/testing/selftests/kvm/x86_64/state_test.c b/tools/testing/selftests/kvm/x86_64/state_test.c
index f6c8b9042f8a..88b58aab7207 100644
--- a/tools/testing/selftests/kvm/x86_64/state_test.c
+++ b/tools/testing/selftests/kvm/x86_64/state_test.c
@@ -20,7 +20,6 @@
#include "vmx.h"
#include "svm_util.h"
-#define VCPU_ID 5
#define L2_GUEST_STACK_SIZE 256
void svm_l2_guest_code(void)
@@ -140,10 +139,87 @@ static void vmx_l1_guest_code(struct vmx_pages *vmx_pages)
static void __attribute__((__flatten__)) guest_code(void *arg)
{
GUEST_SYNC(1);
+
+ if (this_cpu_has(X86_FEATURE_XSAVE)) {
+ uint64_t supported_xcr0 = this_cpu_supported_xcr0();
+ uint8_t buffer[4096];
+
+ memset(buffer, 0xcc, sizeof(buffer));
+
+ set_cr4(get_cr4() | X86_CR4_OSXSAVE);
+ GUEST_ASSERT(this_cpu_has(X86_FEATURE_OSXSAVE));
+
+ xsetbv(0, xgetbv(0) | supported_xcr0);
+
+ /*
+ * Modify state for all supported xfeatures to take them out of
+ * their "init" state, i.e. to make them show up in XSTATE_BV.
+ *
+ * Note off-by-default features, e.g. AMX, are out of scope for
+ * this particular testcase as they have a different ABI.
+ */
+ GUEST_ASSERT(supported_xcr0 & XFEATURE_MASK_FP);
+ asm volatile ("fincstp");
+
+ GUEST_ASSERT(supported_xcr0 & XFEATURE_MASK_SSE);
+ asm volatile ("vmovdqu %0, %%xmm0" :: "m" (buffer));
+
+ if (supported_xcr0 & XFEATURE_MASK_YMM)
+ asm volatile ("vmovdqu %0, %%ymm0" :: "m" (buffer));
+
+ if (supported_xcr0 & XFEATURE_MASK_AVX512) {
+ asm volatile ("kmovq %0, %%k1" :: "r" (-1ull));
+ asm volatile ("vmovupd %0, %%zmm0" :: "m" (buffer));
+ asm volatile ("vmovupd %0, %%zmm16" :: "m" (buffer));
+ }
+
+ if (this_cpu_has(X86_FEATURE_MPX)) {
+ uint64_t bounds[2] = { 10, 0xffffffffull };
+ uint64_t output[2] = { };
+
+ GUEST_ASSERT(supported_xcr0 & XFEATURE_MASK_BNDREGS);
+ GUEST_ASSERT(supported_xcr0 & XFEATURE_MASK_BNDCSR);
+
+ /*
+ * Don't bother trying to get BNDCSR into the INUSE
+ * state. MSR_IA32_BNDCFGS doesn't count as it isn't
+ * managed via XSAVE/XRSTOR, and BNDCFGU can only be
+ * modified by XRSTOR. Stuffing XSTATE_BV in the host
+ * is simpler than doing XRSTOR here in the guest.
+ *
+ * However, temporarily enable MPX in BNDCFGS so that
+ * BNDMOV actually loads BND1. If MPX isn't *fully*
+ * enabled, all MPX instructions are treated as NOPs.
+ *
+ * Hand encode "bndmov (%rax),%bnd1" as support for MPX
+ * mnemonics/registers has been removed from gcc and
+ * clang (and was never fully supported by clang).
+ */
+ wrmsr(MSR_IA32_BNDCFGS, BIT_ULL(0));
+ asm volatile (".byte 0x66,0x0f,0x1a,0x08" :: "a" (bounds));
+ /*
+ * Hand encode "bndmov %bnd1, (%rax)" to sanity check
+ * that BND1 actually got loaded.
+ */
+ asm volatile (".byte 0x66,0x0f,0x1b,0x08" :: "a" (output));
+ wrmsr(MSR_IA32_BNDCFGS, 0);
+
+ GUEST_ASSERT_EQ(bounds[0], output[0]);
+ GUEST_ASSERT_EQ(bounds[1], output[1]);
+ }
+ if (this_cpu_has(X86_FEATURE_PKU)) {
+ GUEST_ASSERT(supported_xcr0 & XFEATURE_MASK_PKRU);
+ set_cr4(get_cr4() | X86_CR4_PKE);
+ GUEST_ASSERT(this_cpu_has(X86_FEATURE_OSPKE));
+
+ wrpkru(-1u);
+ }
+ }
+
GUEST_SYNC(2);
if (arg) {
- if (cpu_has_svm())
+ if (this_cpu_has(X86_FEATURE_SVM))
svm_l1_guest_code(arg);
else
vmx_l1_guest_code(arg);
@@ -154,45 +230,40 @@ static void __attribute__((__flatten__)) guest_code(void *arg)
int main(int argc, char *argv[])
{
+ uint64_t *xstate_bv, saved_xstate_bv;
vm_vaddr_t nested_gva = 0;
-
+ struct kvm_cpuid2 empty_cpuid = {};
struct kvm_regs regs1, regs2;
+ struct kvm_vcpu *vcpu, *vcpuN;
struct kvm_vm *vm;
- struct kvm_run *run;
struct kvm_x86_state *state;
struct ucall uc;
int stage;
/* Create VM */
- vm = vm_create_default(VCPU_ID, 0, guest_code);
- vcpu_set_cpuid(vm, VCPU_ID, kvm_get_supported_cpuid());
- run = vcpu_state(vm, VCPU_ID);
+ vm = vm_create_with_one_vcpu(&vcpu, guest_code);
- vcpu_regs_get(vm, VCPU_ID, &regs1);
+ vcpu_regs_get(vcpu, &regs1);
- if (kvm_check_cap(KVM_CAP_NESTED_STATE)) {
- if (nested_svm_supported())
+ if (kvm_has_cap(KVM_CAP_NESTED_STATE)) {
+ if (kvm_cpu_has(X86_FEATURE_SVM))
vcpu_alloc_svm(vm, &nested_gva);
- else if (nested_vmx_supported())
+ else if (kvm_cpu_has(X86_FEATURE_VMX))
vcpu_alloc_vmx(vm, &nested_gva);
}
if (!nested_gva)
pr_info("will skip nested state checks\n");
- vcpu_args_set(vm, VCPU_ID, 1, nested_gva);
+ vcpu_args_set(vcpu, 1, nested_gva);
for (stage = 1;; stage++) {
- _vcpu_run(vm, VCPU_ID);
- TEST_ASSERT(run->exit_reason == KVM_EXIT_IO,
- "Stage %d: unexpected exit reason: %u (%s),\n",
- stage, run->exit_reason,
- exit_reason_str(run->exit_reason));
+ vcpu_run(vcpu);
+ TEST_ASSERT_KVM_EXIT_REASON(vcpu, KVM_EXIT_IO);
- switch (get_ucall(vm, VCPU_ID, &uc)) {
+ switch (get_ucall(vcpu, &uc)) {
case UCALL_ABORT:
- TEST_FAIL("%s at %s:%ld", (const char *)uc.args[0],
- __FILE__, uc.args[1]);
+ REPORT_GUEST_ASSERT(uc);
/* NOT REACHED */
case UCALL_SYNC:
break;
@@ -207,22 +278,47 @@ int main(int argc, char *argv[])
uc.args[1] == stage, "Stage %d: Unexpected register values vmexit, got %lx",
stage, (ulong)uc.args[1]);
- state = vcpu_save_state(vm, VCPU_ID);
+ state = vcpu_save_state(vcpu);
memset(&regs1, 0, sizeof(regs1));
- vcpu_regs_get(vm, VCPU_ID, &regs1);
+ vcpu_regs_get(vcpu, &regs1);
kvm_vm_release(vm);
/* Restore state in a new VM. */
- kvm_vm_restart(vm, O_RDWR);
- vm_vcpu_add(vm, VCPU_ID);
- vcpu_set_cpuid(vm, VCPU_ID, kvm_get_supported_cpuid());
- vcpu_load_state(vm, VCPU_ID, state);
- run = vcpu_state(vm, VCPU_ID);
- free(state);
+ vcpu = vm_recreate_with_one_vcpu(vm);
+ vcpu_load_state(vcpu, state);
+
+ /*
+ * Restore XSAVE state in a dummy vCPU, first without doing
+ * KVM_SET_CPUID2, and then with an empty guest CPUID. Except
+ * for off-by-default xfeatures, e.g. AMX, KVM is supposed to
+ * allow KVM_SET_XSAVE regardless of guest CPUID. Manually
+ * load only XSAVE state, MSRs in particular have a much more
+ * convoluted ABI.
+ *
+ * Load two versions of XSAVE state: one with the actual guest
+ * XSAVE state, and one with all supported features forced "on"
+ * in xstate_bv, e.g. to ensure that KVM allows loading all
+ * supported features, even if something goes awry in saving
+ * the original snapshot.
+ */
+ xstate_bv = (void *)&((uint8_t *)state->xsave->region)[512];
+ saved_xstate_bv = *xstate_bv;
+
+ vcpuN = __vm_vcpu_add(vm, vcpu->id + 1);
+ vcpu_xsave_set(vcpuN, state->xsave);
+ *xstate_bv = kvm_cpu_supported_xcr0();
+ vcpu_xsave_set(vcpuN, state->xsave);
+
+ vcpu_init_cpuid(vcpuN, &empty_cpuid);
+ vcpu_xsave_set(vcpuN, state->xsave);
+ *xstate_bv = saved_xstate_bv;
+ vcpu_xsave_set(vcpuN, state->xsave);
+
+ kvm_x86_state_cleanup(state);
memset(&regs2, 0, sizeof(regs2));
- vcpu_regs_get(vm, VCPU_ID, &regs2);
+ vcpu_regs_get(vcpu, &regs2);
TEST_ASSERT(!memcmp(&regs1, &regs2, sizeof(regs2)),
"Unexpected register values after vcpu_load_state; rdi: %lx rsi: %lx",
(ulong) regs2.rdi, (ulong) regs2.rsi);
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.