[PATCH 03/42] KVM: selftests: Add framework to query KVM CPUID bits
From: Sean Christopherson
Date: Fri Jun 03 2022 - 21:21:21 EST
Add X86_FEATURE_* magic in the style of KVM-Unit-Tests' implementation,
where the CPUID function, index, output register, and output bit position
are embedded in the macro value. Add kvm_cpu_has() to query KVM's
supported CPUID and use it set_sregs_test, which is the most prolific
user of manual feature querying.
Opportunstically rename calc_cr4_feature_bits() to
calc_supported_cr4_feature_bits() to better capture how the CR4 bits are
chosen.
Link: https://lore.kernel.org/all/20210422005626.564163-1-ricarkol@xxxxxxxxxx
Suggested-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Suggested-by: Jim Mattson <jmattson@xxxxxxxxxx>
Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
---
.../selftests/kvm/include/x86_64/processor.h | 106 ++++++++++++++++--
.../selftests/kvm/lib/x86_64/processor.c | 22 ++++
.../selftests/kvm/x86_64/set_sregs_test.c | 28 ++---
3 files changed, 128 insertions(+), 28 deletions(-)
diff --git a/tools/testing/selftests/kvm/include/x86_64/processor.h b/tools/testing/selftests/kvm/include/x86_64/processor.h
index e47eba48744e..59ae869814b7 100644
--- a/tools/testing/selftests/kvm/include/x86_64/processor.h
+++ b/tools/testing/selftests/kvm/include/x86_64/processor.h
@@ -43,23 +43,96 @@
#define X86_CR4_SMAP (1ul << 21)
#define X86_CR4_PKE (1ul << 22)
+/* Note, these are ordered alphabetically to match kvm_cpuid_entry2. Eww. */
+enum cpuid_output_regs {
+ KVM_CPUID_EAX,
+ KVM_CPUID_EBX,
+ KVM_CPUID_ECX,
+ KVM_CPUID_EDX
+};
+
+/*
+ * Pack the information into a 64-bit value so that each X86_FEATURE_XXX can be
+ * passed by value with no overhead.
+ */
+struct kvm_x86_cpu_feature {
+ u32 function;
+ u16 index;
+ u8 reg;
+ u8 bit;
+};
+#define KVM_X86_CPU_FEATURE(fn, idx, gpr, __bit) \
+({ \
+ struct kvm_x86_cpu_feature feature = { \
+ .function = fn, \
+ .index = idx, \
+ .reg = KVM_CPUID_##gpr, \
+ .bit = __bit, \
+ }; \
+ \
+ feature; \
+})
+
+/*
+ * Basic Leafs, a.k.a. Intel defined
+ */
+#define X86_FEATURE_MWAIT KVM_X86_CPU_FEATURE(0x1, 0, ECX, 3)
+#define X86_FEATURE_VMX KVM_X86_CPU_FEATURE(0x1, 0, ECX, 5)
+#define X86_FEATURE_SMX KVM_X86_CPU_FEATURE(0x1, 0, ECX, 6)
+#define X86_FEATURE_PCID KVM_X86_CPU_FEATURE(0x1, 0, ECX, 17)
+#define X86_FEATURE_MOVBE KVM_X86_CPU_FEATURE(0x1, 0, ECX, 22)
+#define X86_FEATURE_TSC_DEADLINE_TIMER KVM_X86_CPU_FEATURE(0x1, 0, ECX, 24)
+#define X86_FEATURE_XSAVE KVM_X86_CPU_FEATURE(0x1, 0, ECX, 26)
+#define X86_FEATURE_OSXSAVE KVM_X86_CPU_FEATURE(0x1, 0, ECX, 27)
+#define X86_FEATURE_RDRAND KVM_X86_CPU_FEATURE(0x1, 0, ECX, 30)
+#define X86_FEATURE_MCE KVM_X86_CPU_FEATURE(0x1, 0, EDX, 7)
+#define X86_FEATURE_APIC KVM_X86_CPU_FEATURE(0x1, 0, EDX, 9)
+#define X86_FEATURE_CLFLUSH KVM_X86_CPU_FEATURE(0x1, 0, EDX, 19)
+#define X86_FEATURE_XMM KVM_X86_CPU_FEATURE(0x1, 0, EDX, 25)
+#define X86_FEATURE_XMM2 KVM_X86_CPU_FEATURE(0x1, 0, EDX, 26)
+#define X86_FEATURE_FSGSBASE KVM_X86_CPU_FEATURE(0x7, 0, EBX, 0)
+#define X86_FEATURE_TSC_ADJUST KVM_X86_CPU_FEATURE(0x7, 0, EBX, 1)
+#define X86_FEATURE_HLE KVM_X86_CPU_FEATURE(0x7, 0, EBX, 4)
+#define X86_FEATURE_SMEP KVM_X86_CPU_FEATURE(0x7, 0, EBX, 7)
+#define X86_FEATURE_INVPCID KVM_X86_CPU_FEATURE(0x7, 0, EBX, 10)
+#define X86_FEATURE_RTM KVM_X86_CPU_FEATURE(0x7, 0, EBX, 11)
+#define X86_FEATURE_SMAP KVM_X86_CPU_FEATURE(0x7, 0, EBX, 20)
+#define X86_FEATURE_PCOMMIT KVM_X86_CPU_FEATURE(0x7, 0, EBX, 22)
+#define X86_FEATURE_CLFLUSHOPT KVM_X86_CPU_FEATURE(0x7, 0, EBX, 23)
+#define X86_FEATURE_CLWB KVM_X86_CPU_FEATURE(0x7, 0, EBX, 24)
+#define X86_FEATURE_UMIP KVM_X86_CPU_FEATURE(0x7, 0, ECX, 2)
+#define X86_FEATURE_PKU KVM_X86_CPU_FEATURE(0x7, 0, ECX, 3)
+#define X86_FEATURE_LA57 KVM_X86_CPU_FEATURE(0x7, 0, ECX, 16)
+#define X86_FEATURE_RDPID KVM_X86_CPU_FEATURE(0x7, 0, ECX, 22)
+#define X86_FEATURE_SHSTK KVM_X86_CPU_FEATURE(0x7, 0, ECX, 7)
+#define X86_FEATURE_IBT KVM_X86_CPU_FEATURE(0x7, 0, EDX, 20)
+#define X86_FEATURE_SPEC_CTRL KVM_X86_CPU_FEATURE(0x7, 0, EDX, 26)
+#define X86_FEATURE_ARCH_CAPABILITIES KVM_X86_CPU_FEATURE(0x7, 0, EDX, 29)
+#define X86_FEATURE_PKS KVM_X86_CPU_FEATURE(0x7, 0, ECX, 31)
+
+/*
+ * Extended Leafs, a.k.a. AMD defined
+ */
+#define X86_FEATURE_SVM KVM_X86_CPU_FEATURE(0x80000001, 0, ECX, 2)
+#define X86_FEATURE_NX KVM_X86_CPU_FEATURE(0x80000001, 0, EDX, 20)
+#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)
+#define X86_FEATURE_RDPRU KVM_X86_CPU_FEATURE(0x80000008, 0, EBX, 4)
+#define X86_FEATURE_AMD_IBPB KVM_X86_CPU_FEATURE(0x80000008, 0, EBX, 12)
+#define X86_FEATURE_NPT KVM_X86_CPU_FEATURE(0x8000000A, 0, EDX, 0)
+#define X86_FEATURE_LBRV KVM_X86_CPU_FEATURE(0x8000000A, 0, EDX, 1)
+#define X86_FEATURE_NRIPS KVM_X86_CPU_FEATURE(0x8000000A, 0, EDX, 3)
+#define X86_FEATURE_TSCRATEMSR KVM_X86_CPU_FEATURE(0x8000000A, 0, EDX, 4)
+#define X86_FEATURE_PAUSEFILTER KVM_X86_CPU_FEATURE(0x8000000A, 0, EDX, 10)
+#define X86_FEATURE_PFTHRESHOLD KVM_X86_CPU_FEATURE(0x8000000A, 0, EDX, 12)
+#define X86_FEATURE_VGIF KVM_X86_CPU_FEATURE(0x8000000A, 0, EDX, 16)
+
/* CPUID.1.ECX */
#define CPUID_VMX (1ul << 5)
-#define CPUID_SMX (1ul << 6)
-#define CPUID_PCID (1ul << 17)
#define CPUID_XSAVE (1ul << 26)
#define CPUID_OSXSAVE (1ul << 27)
-/* CPUID.7.EBX */
-#define CPUID_FSGSBASE (1ul << 0)
-#define CPUID_SMEP (1ul << 7)
-#define CPUID_SMAP (1ul << 20)
-
-/* CPUID.7.ECX */
-#define CPUID_UMIP (1ul << 2)
-#define CPUID_PKU (1ul << 3)
-#define CPUID_LA57 (1ul << 16)
-
/* CPUID.0x8000_0001.EDX */
#define CPUID_GBPAGES (1ul << 26)
@@ -488,6 +561,15 @@ static inline void vcpu_xcrs_set(struct kvm_vcpu *vcpu, struct kvm_xcrs *xcrs)
}
struct kvm_cpuid2 *kvm_get_supported_cpuid(void);
+
+bool kvm_cpuid_has(const struct kvm_cpuid2 *cpuid,
+ struct kvm_x86_cpu_feature feature);
+
+static inline bool kvm_cpu_has(struct kvm_x86_cpu_feature feature)
+{
+ return kvm_cpuid_has(kvm_get_supported_cpuid(), feature);
+}
+
struct kvm_cpuid2 *vcpu_get_cpuid(struct kvm_vcpu *vcpu);
static inline int __vcpu_set_cpuid(struct kvm_vcpu *vcpu,
diff --git a/tools/testing/selftests/kvm/lib/x86_64/processor.c b/tools/testing/selftests/kvm/lib/x86_64/processor.c
index ea246a87c446..e60afab6b88f 100644
--- a/tools/testing/selftests/kvm/lib/x86_64/processor.c
+++ b/tools/testing/selftests/kvm/lib/x86_64/processor.c
@@ -735,6 +735,28 @@ struct kvm_cpuid2 *kvm_get_supported_cpuid(void)
return cpuid;
}
+bool kvm_cpuid_has(const struct kvm_cpuid2 *cpuid,
+ struct kvm_x86_cpu_feature feature)
+{
+ const struct kvm_cpuid_entry2 *entry;
+ int i;
+
+ for (i = 0; i < cpuid->nent; i++) {
+ entry = &cpuid->entries[i];
+
+ /*
+ * The output registers in kvm_cpuid_entry2 are in alphabetical
+ * order, but kvm_x86_cpu_feature matches that mess, so yay
+ * pointer shenanigans!
+ */
+ if (entry->function == feature.function &&
+ entry->index == feature.index)
+ return (&entry->eax)[feature.reg] & BIT(feature.bit);
+ }
+
+ return false;
+}
+
uint64_t kvm_get_feature_msr(uint64_t msr_index)
{
struct {
diff --git a/tools/testing/selftests/kvm/x86_64/set_sregs_test.c b/tools/testing/selftests/kvm/x86_64/set_sregs_test.c
index dd344439ad33..2bb08bf2125d 100644
--- a/tools/testing/selftests/kvm/x86_64/set_sregs_test.c
+++ b/tools/testing/selftests/kvm/x86_64/set_sregs_test.c
@@ -43,36 +43,32 @@ static void test_cr4_feature_bit(struct kvm_vcpu *vcpu, struct kvm_sregs *orig,
TEST_ASSERT(!memcmp(&sregs, orig, sizeof(sregs)), "KVM modified sregs");
}
-static uint64_t calc_cr4_feature_bits(struct kvm_vm *vm)
+static uint64_t calc_supported_cr4_feature_bits(void)
{
- struct kvm_cpuid_entry2 *cpuid_1, *cpuid_7;
uint64_t cr4;
- cpuid_1 = kvm_get_supported_cpuid_entry(1);
- cpuid_7 = kvm_get_supported_cpuid_entry(7);
-
cr4 = X86_CR4_VME | X86_CR4_PVI | X86_CR4_TSD | X86_CR4_DE |
X86_CR4_PSE | X86_CR4_PAE | X86_CR4_MCE | X86_CR4_PGE |
X86_CR4_PCE | X86_CR4_OSFXSR | X86_CR4_OSXMMEXCPT;
- if (cpuid_7->ecx & CPUID_UMIP)
+ if (kvm_cpu_has(X86_FEATURE_UMIP))
cr4 |= X86_CR4_UMIP;
- if (cpuid_7->ecx & CPUID_LA57)
+ if (kvm_cpu_has(X86_FEATURE_LA57))
cr4 |= X86_CR4_LA57;
- if (cpuid_1->ecx & CPUID_VMX)
+ if (kvm_cpu_has(X86_FEATURE_VMX))
cr4 |= X86_CR4_VMXE;
- if (cpuid_1->ecx & CPUID_SMX)
+ if (kvm_cpu_has(X86_FEATURE_SMX))
cr4 |= X86_CR4_SMXE;
- if (cpuid_7->ebx & CPUID_FSGSBASE)
+ if (kvm_cpu_has(X86_FEATURE_FSGSBASE))
cr4 |= X86_CR4_FSGSBASE;
- if (cpuid_1->ecx & CPUID_PCID)
+ if (kvm_cpu_has(X86_FEATURE_PCID))
cr4 |= X86_CR4_PCIDE;
- if (cpuid_1->ecx & CPUID_XSAVE)
+ if (kvm_cpu_has(X86_FEATURE_XSAVE))
cr4 |= X86_CR4_OSXSAVE;
- if (cpuid_7->ebx & CPUID_SMEP)
+ if (kvm_cpu_has(X86_FEATURE_SMEP))
cr4 |= X86_CR4_SMEP;
- if (cpuid_7->ebx & CPUID_SMAP)
+ if (kvm_cpu_has(X86_FEATURE_SMAP))
cr4 |= X86_CR4_SMAP;
- if (cpuid_7->ecx & CPUID_PKU)
+ if (kvm_cpu_has(X86_FEATURE_PKU))
cr4 |= X86_CR4_PKE;
return cr4;
@@ -99,7 +95,7 @@ int main(int argc, char *argv[])
vcpu_sregs_get(vcpu, &sregs);
- sregs.cr4 |= calc_cr4_feature_bits(vm);
+ sregs.cr4 |= calc_supported_cr4_feature_bits();
cr4 = sregs.cr4;
rc = _vcpu_sregs_set(vcpu, &sregs);
--
2.36.1.255.ge46751e96f-goog