Use boot_cpu_has() to check for NX support now that KVM requires
host_efer.NX=1 if NX is supported. Opportunistically avoid the guest
CPUID lookup in cpuid_fix_nx_cap() if NX is supported, which is by far
the common case.
Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
---
arch/x86/kvm/cpuid.c | 13 +++++--------
1 file changed, 5 insertions(+), 8 deletions(-)
diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index b4da665bb892..786f556302cd 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -208,16 +208,14 @@ static void kvm_vcpu_after_set_cpuid(struct kvm_vcpu *vcpu)
kvm_mmu_reset_context(vcpu);
}
-static int is_efer_nx(void)
-{
- return host_efer & EFER_NX;
-}
-
static void cpuid_fix_nx_cap(struct kvm_vcpu *vcpu)
{
int i;
struct kvm_cpuid_entry2 *e, *entry;
+ if (boot_cpu_has(X86_FEATURE_NX))
+ return;
+
entry = NULL;
for (i = 0; i < vcpu->arch.cpuid_nent; ++i) {
e = &vcpu->arch.cpuid_entries[i];
@@ -226,7 +224,7 @@ static void cpuid_fix_nx_cap(struct kvm_vcpu *vcpu)
break;
}
}
- if (entry && cpuid_entry_has(entry, X86_FEATURE_NX) && !is_efer_nx()) {
+ if (entry && cpuid_entry_has(entry, X86_FEATURE_NX)) {
cpuid_entry_clear(entry, X86_FEATURE_NX);
printk(KERN_INFO "kvm: guest NX capability removed\n");
}
@@ -401,7 +399,6 @@ static __always_inline void kvm_cpu_cap_mask(enum cpuid_leafs leaf, u32 mask)
void kvm_set_cpu_caps(void)
{
- unsigned int f_nx = is_efer_nx() ? F(NX) : 0;
#ifdef CONFIG_X86_64
unsigned int f_gbpages = F(GBPAGES);
unsigned int f_lm = F(LM);
@@ -515,7 +512,7 @@ void kvm_set_cpu_caps(void)
F(CX8) | F(APIC) | 0 /* Reserved */ | F(SYSCALL) |
F(MTRR) | F(PGE) | F(MCA) | F(CMOV) |
F(PAT) | F(PSE36) | 0 /* Reserved */ |
- f_nx | 0 /* Reserved */ | F(MMXEXT) | F(MMX) |
+ F(NX) | 0 /* Reserved */ | F(MMXEXT) | F(MMX) |
F(FXSR) | F(FXSR_OPT) | f_gbpages | F(RDTSCP) |
0 /* Reserved */ | f_lm | F(3DNOWEXT) | F(3DNOW)
);
--
2.32.0.272.g935e593368-goog
