[PATCH 7/7] KVM: selftests: Extend set_sregs test to cover EFER
From: Yosry Ahmed
Date: Tue Jun 30 2026 - 19:49:59 EST
Extend the set_sregs test to cover various bits in EFER. Update
TEST_INVALID_CR_BIT() to operate on EFER as well as CRx (and rename it
accordingly). Add test cases to check that EFER bits are disallowed
without the relevant CPUID enablement.
Assisted-by: Gemini:unknown-version
Signed-off-by: Yosry Ahmed <yosry@xxxxxxxxxx>
---
.../selftests/kvm/include/x86/processor.h | 2 +
.../selftests/kvm/x86/set_sregs_test.c | 83 ++++++++++++++-----
2 files changed, 64 insertions(+), 21 deletions(-)
diff --git a/tools/testing/selftests/kvm/include/x86/processor.h b/tools/testing/selftests/kvm/include/x86/processor.h
index 7d3a27bc0d842..b161174ece453 100644
--- a/tools/testing/selftests/kvm/include/x86/processor.h
+++ b/tools/testing/selftests/kvm/include/x86/processor.h
@@ -208,6 +208,7 @@ struct kvm_x86_cpu_feature {
#define X86_FEATURE_PERFCTR_NB KVM_X86_CPU_FEATURE(0x80000001, 0, ECX, 24)
#define X86_FEATURE_PERFCTR_LLC KVM_X86_CPU_FEATURE(0x80000001, 0, ECX, 28)
#define X86_FEATURE_NX KVM_X86_CPU_FEATURE(0x80000001, 0, EDX, 20)
+#define X86_FEATURE_FXSR_OPT KVM_X86_CPU_FEATURE(0x80000001, 0, EDX, 25)
#define X86_FEATURE_GBPAGES KVM_X86_CPU_FEATURE(0x80000001, 0, EDX, 26)
#define X86_FEATURE_RDTSCP KVM_X86_CPU_FEATURE(0x80000001, 0, EDX, 27)
#define X86_FEATURE_LM KVM_X86_CPU_FEATURE(0x80000001, 0, EDX, 29)
@@ -226,6 +227,7 @@ struct kvm_x86_cpu_feature {
#define X86_FEATURE_SEV KVM_X86_CPU_FEATURE(0x8000001F, 0, EAX, 1)
#define X86_FEATURE_SEV_ES KVM_X86_CPU_FEATURE(0x8000001F, 0, EAX, 3)
#define X86_FEATURE_SEV_SNP KVM_X86_CPU_FEATURE(0x8000001F, 0, EAX, 4)
+#define X86_FEATURE_AUTOIBRS KVM_X86_CPU_FEATURE(0x80000021, 0, EAX, 8)
#define X86_FEATURE_GP_ON_USER_CPUID KVM_X86_CPU_FEATURE(0x80000021, 0, EAX, 17)
#define X86_FEATURE_PERFMON_V2 KVM_X86_CPU_FEATURE(0x80000022, 0, EAX, 0)
#define X86_FEATURE_LBR_PMC_FREEZE KVM_X86_CPU_FEATURE(0x80000022, 0, EAX, 2)
diff --git a/tools/testing/selftests/kvm/x86/set_sregs_test.c b/tools/testing/selftests/kvm/x86/set_sregs_test.c
index 8e654cc9ab168..562afab378d11 100644
--- a/tools/testing/selftests/kvm/x86/set_sregs_test.c
+++ b/tools/testing/selftests/kvm/x86/set_sregs_test.c
@@ -21,20 +21,20 @@
#include "kvm_util.h"
#include "processor.h"
-#define TEST_INVALID_CR_BIT(vcpu, cr, orig, bit) \
+#define TEST_INVALID_SREG_BIT(vcpu, reg, orig, bit) \
do { \
struct kvm_sregs new; \
int rc; \
\
/* Skip the sub-test, the feature/bit is supported. */ \
- if (orig.cr & bit) \
+ if (orig.reg & bit) \
break; \
\
- memcpy(&new, &orig, sizeof(sregs)); \
- new.cr |= bit; \
+ memcpy(&new, &orig, sizeof(new)); \
+ new.reg |= bit; \
\
rc = _vcpu_sregs_set(vcpu, &new); \
- TEST_ASSERT(rc, "KVM allowed invalid " #cr " bit (0x%lx)", bit); \
+ TEST_ASSERT(rc, "KVM allowed invalid " #reg " bit (0x%llx)", (unsigned long long)bit); \
\
/* Sanity check that KVM didn't change anything. */ \
vcpu_sregs_get(vcpu, &new); \
@@ -46,6 +46,8 @@ do { \
X86_CR4_MCE | X86_CR4_PGE | X86_CR4_PCE | \
X86_CR4_OSFXSR | X86_CR4_OSXMMEXCPT)
+#define KVM_ALWAYS_ALLOWED_EFER EFER_SCE
+
static u64 calc_supported_cr4_feature_bits(void)
{
u64 cr4 = KVM_ALWAYS_ALLOWED_CR4;
@@ -74,6 +76,24 @@ static u64 calc_supported_cr4_feature_bits(void)
return cr4;
}
+static u64 calc_supported_efer_feature_bits(void)
+{
+ u64 efer = KVM_ALWAYS_ALLOWED_EFER;
+
+ if (kvm_cpu_has(X86_FEATURE_LM))
+ efer |= (EFER_LME | EFER_LMA);
+ if (kvm_cpu_has(X86_FEATURE_NX))
+ efer |= EFER_NX;
+ if (kvm_cpu_has(X86_FEATURE_SVM))
+ efer |= EFER_SVME;
+ if (kvm_cpu_has(X86_FEATURE_FXSR_OPT))
+ efer |= EFER_FFXSR;
+ if (kvm_cpu_has(X86_FEATURE_AUTOIBRS))
+ efer |= EFER_AUTOIBRS;
+
+ return efer;
+}
+
static void test_cr_bits(struct kvm_vcpu *vcpu, u64 cr4)
{
struct kvm_sregs sregs;
@@ -96,26 +116,45 @@ static void test_cr_bits(struct kvm_vcpu *vcpu, u64 cr4)
(sregs.cr4 & X86_CR4_PKE) ? "set" : "clear");
vcpu_sregs_get(vcpu, &sregs);
- TEST_ASSERT(sregs.cr4 == cr4, "sregs.CR4 (0x%llx) != CR4 (0x%lx)",
- sregs.cr4, cr4);
-
- TEST_INVALID_CR_BIT(vcpu, cr4, sregs, X86_CR4_UMIP);
- TEST_INVALID_CR_BIT(vcpu, cr4, sregs, X86_CR4_LA57);
- TEST_INVALID_CR_BIT(vcpu, cr4, sregs, X86_CR4_VMXE);
- TEST_INVALID_CR_BIT(vcpu, cr4, sregs, X86_CR4_SMXE);
- TEST_INVALID_CR_BIT(vcpu, cr4, sregs, X86_CR4_FSGSBASE);
- TEST_INVALID_CR_BIT(vcpu, cr4, sregs, X86_CR4_PCIDE);
- TEST_INVALID_CR_BIT(vcpu, cr4, sregs, X86_CR4_OSXSAVE);
- TEST_INVALID_CR_BIT(vcpu, cr4, sregs, X86_CR4_SMEP);
- TEST_INVALID_CR_BIT(vcpu, cr4, sregs, X86_CR4_SMAP);
- TEST_INVALID_CR_BIT(vcpu, cr4, sregs, X86_CR4_PKE);
+ TEST_ASSERT_EQ(sregs.cr4, cr4);
+
+ TEST_INVALID_SREG_BIT(vcpu, cr4, sregs, X86_CR4_UMIP);
+ TEST_INVALID_SREG_BIT(vcpu, cr4, sregs, X86_CR4_LA57);
+ TEST_INVALID_SREG_BIT(vcpu, cr4, sregs, X86_CR4_VMXE);
+ TEST_INVALID_SREG_BIT(vcpu, cr4, sregs, X86_CR4_SMXE);
+ TEST_INVALID_SREG_BIT(vcpu, cr4, sregs, X86_CR4_FSGSBASE);
+ TEST_INVALID_SREG_BIT(vcpu, cr4, sregs, X86_CR4_PCIDE);
+ TEST_INVALID_SREG_BIT(vcpu, cr4, sregs, X86_CR4_OSXSAVE);
+ TEST_INVALID_SREG_BIT(vcpu, cr4, sregs, X86_CR4_SMEP);
+ TEST_INVALID_SREG_BIT(vcpu, cr4, sregs, X86_CR4_SMAP);
+ TEST_INVALID_SREG_BIT(vcpu, cr4, sregs, X86_CR4_PKE);
for (i = 32; i < 64; i++)
- TEST_INVALID_CR_BIT(vcpu, cr0, sregs, BIT(i));
+ TEST_INVALID_SREG_BIT(vcpu, cr0, sregs, BIT(i));
/* NW without CD is illegal, as is PG without PE. */
- TEST_INVALID_CR_BIT(vcpu, cr0, sregs, X86_CR0_NW);
- TEST_INVALID_CR_BIT(vcpu, cr0, sregs, X86_CR0_PG);
+ TEST_INVALID_SREG_BIT(vcpu, cr0, sregs, X86_CR0_NW);
+ TEST_INVALID_SREG_BIT(vcpu, cr0, sregs, X86_CR0_PG);
+}
+
+static void test_efer_bits(struct kvm_vcpu *vcpu, u64 efer)
+{
+ struct kvm_sregs sregs;
+ int rc;
+
+ vcpu_sregs_get(vcpu, &sregs);
+ sregs.efer |= efer;
+ rc = _vcpu_sregs_set(vcpu, &sregs);
+ TEST_ASSERT(!rc, "Failed to set supported EFER bits (0x%llx)", sregs.efer);
+
+ vcpu_sregs_get(vcpu, &sregs);
+ TEST_ASSERT_EQ(sregs.efer, efer);
+
+ TEST_INVALID_SREG_BIT(vcpu, efer, sregs, EFER_LME);
+ TEST_INVALID_SREG_BIT(vcpu, efer, sregs, EFER_NX);
+ TEST_INVALID_SREG_BIT(vcpu, efer, sregs, EFER_SVME);
+ TEST_INVALID_SREG_BIT(vcpu, efer, sregs, EFER_FFXSR);
+ TEST_INVALID_SREG_BIT(vcpu, efer, sregs, EFER_AUTOIBRS);
}
int main(int argc, char *argv[])
@@ -132,6 +171,7 @@ int main(int argc, char *argv[])
*/
vm = vm_create_barebones();
vcpu = __vm_vcpu_add(vm, 0);
+ test_efer_bits(vcpu, KVM_ALWAYS_ALLOWED_EFER);
test_cr_bits(vcpu, KVM_ALWAYS_ALLOWED_CR4);
kvm_vm_free(vm);
@@ -151,6 +191,7 @@ int main(int argc, char *argv[])
sregs.apic_base);
test_cr_bits(vcpu, calc_supported_cr4_feature_bits());
+ test_efer_bits(vcpu, calc_supported_efer_feature_bits());
kvm_vm_free(vm);
--
2.55.0.rc0.799.gd6f94ed593-goog