[PATCH 1/1] x86/kvm/svm: Implement support for PSFD

From: Ramakrishna Saripalli
Date: Wed Apr 07 2021 - 15:45:50 EST


From: Ramakrishna Saripalli <rk.saripalli@xxxxxxx>

Expose Predictive Store Forwarding capability to guests.
Guests enable or disable PSF via SPEC_CTRL MSR.

Signed-off-by: Ramakrishna Saripalli <rk.saripalli@xxxxxxx>
---
arch/x86/kvm/cpuid.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index 6bd2f8b830e4..9c4af0fef6d7 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -448,6 +448,8 @@ void kvm_set_cpu_caps(void)
kvm_cpu_cap_set(X86_FEATURE_INTEL_STIBP);
if (boot_cpu_has(X86_FEATURE_AMD_SSBD))
kvm_cpu_cap_set(X86_FEATURE_SPEC_CTRL_SSBD);
+ if (boot_cpu_has(X86_FEATURE_AMD_PSFD))
+ kvm_cpu_cap_set(X86_FEATURE_AMD_PSFD);

kvm_cpu_cap_mask(CPUID_7_1_EAX,
F(AVX_VNNI) | F(AVX512_BF16)
@@ -482,7 +484,7 @@ void kvm_set_cpu_caps(void)
kvm_cpu_cap_mask(CPUID_8000_0008_EBX,
F(CLZERO) | F(XSAVEERPTR) |
F(WBNOINVD) | F(AMD_IBPB) | F(AMD_IBRS) | F(AMD_SSBD) | F(VIRT_SSBD) |
- F(AMD_SSB_NO) | F(AMD_STIBP) | F(AMD_STIBP_ALWAYS_ON)
+ F(AMD_SSB_NO) | F(AMD_STIBP) | F(AMD_STIBP_ALWAYS_ON) | F(AMD_PSFD)
);

/*
--
2.25.1