[PATCH 4.9 05/31] KVM: x86: use Intel speculation bugs and features as derived in generic x86 code

Greg Kroah-Hartman
2019-11-15T06:22:38Z

From: Paolo Bonzini <pbonzini@redhat.com>

commit 0c54914d0c52a15db9954a76ce80fee32cf318f4 upstream.

Similar to AMD bits, set the Intel bits from the vendor-independent
feature and bug flags, because KVM_GET_SUPPORTED_CPUID does not care
about the vendor and they should be set on AMD processors as well.

Suggested-by: Jim Mattson <jmattson@google.com>
Reviewed-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
arch/x86/kvm/cpuid.c | 8 ++++++++
arch/x86/kvm/x86.c | 8 ++++++++
2 files changed, 16 insertions(+)

--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -466,8 +466,16 @@ static inline int __do_cpuid_ent(struct
/* PKU is not yet implemented for shadow paging. */
if (!tdp_enabled || !boot_cpu_has(X86_FEATURE_OSPKE))
entry->ecx &= ~F(PKU);
+
entry->edx &= kvm_cpuid_7_0_edx_x86_features;
cpuid_mask(&entry->edx, CPUID_7_EDX);
+ if (boot_cpu_has(X86_FEATURE_IBPB) &&
+ boot_cpu_has(X86_FEATURE_IBRS))
+ entry->edx |= F(SPEC_CTRL);
+ if (boot_cpu_has(X86_FEATURE_STIBP))
+ entry->edx |= F(INTEL_STIBP);
+ if (boot_cpu_has(X86_FEATURE_SSBD))
+ entry->edx |= F(SPEC_CTRL_SSBD);
/*
* We emulate ARCH_CAPABILITIES in software even
* if the host doesn't support it.
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -1043,8 +1043,16 @@ u64 kvm_get_arch_capabilities(void)
if (l1tf_vmx_mitigation != VMENTER_L1D_FLUSH_NEVER)
data |= ARCH_CAP_SKIP_VMENTRY_L1DFLUSH;

+ if (!boot_cpu_has_bug(X86_BUG_CPU_MELTDOWN))
+ data |= ARCH_CAP_RDCL_NO;
+ if (!boot_cpu_has_bug(X86_BUG_SPEC_STORE_BYPASS))
+ data |= ARCH_CAP_SSB_NO;
+ if (!boot_cpu_has_bug(X86_BUG_MDS))
+ data |= ARCH_CAP_MDS_NO;
+
return data;
}
+
EXPORT_SYMBOL_GPL(kvm_get_arch_capabilities);

static int kvm_get_msr_feature(struct kvm_msr_entry *msr)