Add a macro to precisely handle CPUID features that AMD duplicated from
CPUID.0x1.EDX into CPUID.0x8000_0001.EDX. This will allow adding an
assert that all features passed to kvm_cpu_cap_init() match the word being
processed, e.g. to prevent passing a feature from CPUID 0x7 to CPUID 0x1.
Because the kernel simply reuses the X86_FEATURE_* definitions from
CPUID.0x1.EDX, KVM's use of the aliased features would result in false
positives from such an assert.
No functional change intended.
Signed-off-by: Sean Christopherson <sea...@google.com>
---
arch/x86/kvm/cpuid.c | 47 +++++++++++++++++++++++++++-----------------
1 file changed, 29 insertions(+), 18 deletions(-)
diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index 9219e164c810..ddff0c7c78b9 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -648,6 +648,16 @@ static __always_inline void kvm_cpu_cap_init(enum
cpuid_leafs leaf, u32 mask)
(IS_ENABLED(CONFIG_X86_64) ? F(name) : 0); \
})
+/*
+ * Aliased Features - For features in 0x8000_0001.EDX that are duplicates of
+ * identical 0x1.EDX features, and thus are aliased from 0x1 to 0x8000_0001.
+ */
+#define ALIASED_1_EDX_F(name)
\
+({
\
+ BUILD_BUG_ON(__feature_leaf(X86_FEATURE_##name) != CPUID_1_EDX);
\
+ feature_bit(name);
\
+})
+
void kvm_set_cpu_caps(void)
{
memset(kvm_cpu_caps, 0, sizeof(kvm_cpu_caps));
@@ -892,30 +902,30 @@ void kvm_set_cpu_caps(void)
);
kvm_cpu_cap_init(CPUID_8000_0001_EDX,
- F(FPU) |
- F(VME) |
- F(DE) |
- F(PSE) |
- F(TSC) |
- F(MSR) |
- F(PAE) |
- F(MCE) |
- F(CX8) |
- F(APIC) |
+ ALIASED_1_EDX_F(FPU) |
+ ALIASED_1_EDX_F(VME) |
+ ALIASED_1_EDX_F(DE) |
+ ALIASED_1_EDX_F(PSE) |
+ ALIASED_1_EDX_F(TSC) |
+ ALIASED_1_EDX_F(MSR) |
+ ALIASED_1_EDX_F(PAE) |
+ ALIASED_1_EDX_F(MCE) |
+ ALIASED_1_EDX_F(CX8) |
+ ALIASED_1_EDX_F(APIC) |
0 /* Reserved */ |
F(SYSCALL) |
- F(MTRR) |
- F(PGE) |
- F(MCA) |
- F(CMOV) |
- F(PAT) |
- F(PSE36) |
+ ALIASED_1_EDX_F(MTRR) |
+ ALIASED_1_EDX_F(PGE) |
+ ALIASED_1_EDX_F(MCA) |
+ ALIASED_1_EDX_F(CMOV) |
+ ALIASED_1_EDX_F(PAT) |
+ ALIASED_1_EDX_F(PSE36) |
0 /* Reserved */ |
F(NX) |
0 /* Reserved */ |
F(MMXEXT) |
- F(MMX) |
- F(FXSR) |
+ ALIASED_1_EDX_F(MMX) |
+ ALIASED_1_EDX_F(FXSR) |
F(FXSR_OPT) |
X86_64_F(GBPAGES) |
F(RDTSCP) |
@@ -1055,6 +1065,7 @@ EXPORT_SYMBOL_GPL(kvm_set_cpu_caps);
#undef F
#undef SF
#undef X86_64_F
+#undef ALIASED_1_EDX_F
struct kvm_cpuid_array {
struct kvm_cpuid_entry2 *entries;
--
2.47.0.338.g60cca15819-goog
