From e47d86083c66525b89c7fc66cdd64d5937725563 Mon Sep 17 00:00:00 2001 From: Josh Poimboeuf Date: Fri, 25 Aug 2023 00:01:36 -0700 Subject: KVM: x86: Add SBPB support Add support for the AMD Selective Branch Predictor Barrier (SBPB) by advertising the CPUID bit and handling PRED_CMD writes accordingly. Note, like SRSO_NO and IBPB_BRTYPE before it, advertise support for SBPB even if it's not enumerated by in the raw CPUID. Some CPUs that gained support via a uCode patch don't report SBPB via CPUID (the kernel forces the flag). Signed-off-by: Josh Poimboeuf Link: https://lore.kernel.org/r/a4ab1e7fe50096d50fde33e739ed2da40b41ea6a.1692919072.git.jpoimboe@kernel.org Co-developed-by: Sean Christopherson Signed-off-by: Sean Christopherson --- arch/x86/kvm/cpuid.c | 1 + 1 file changed, 1 insertion(+) (limited to 'arch/x86/kvm/cpuid.c') diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index 8f26a929d510..552dc4f3899b 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -764,6 +764,7 @@ void kvm_set_cpu_caps(void) F(NULL_SEL_CLR_BASE) | F(AUTOIBRS) | 0 /* PrefetchCtlMsr */ ); + kvm_cpu_cap_check_and_set(X86_FEATURE_SBPB); kvm_cpu_cap_check_and_set(X86_FEATURE_IBPB_BRTYPE); kvm_cpu_cap_check_and_set(X86_FEATURE_SRSO_NO); -- cgit