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authorPawan Gupta2024-03-11 12:29:43 -0700
committerDave Hansen2024-03-11 13:13:50 -0700
commit2a0180129d726a4b953232175857d442651b55a0 (patch)
tree5ea4ad5ba07c2966d49d4c00d4c2ca0798b37214 /arch/x86
parent8076fcde016c9c0e0660543e67bff86cb48a7c9c (diff)
KVM/x86: Export RFDS_NO and RFDS_CLEAR to guests
Mitigation for RFDS requires RFDS_CLEAR capability which is enumerated by MSR_IA32_ARCH_CAPABILITIES bit 27. If the host has it set, export it to guests so that they can deploy the mitigation. RFDS_NO indicates that the system is not vulnerable to RFDS, export it to guests so that they don't deploy the mitigation unnecessarily. When the host is not affected by X86_BUG_RFDS, but has RFDS_NO=0, synthesize RFDS_NO to the guest. Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Diffstat (limited to 'arch/x86')
-rw-r--r--arch/x86/kvm/x86.c5
1 files changed, 4 insertions, 1 deletions
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 48a61d283406..68fdf3ba031a 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -1623,7 +1623,8 @@ static bool kvm_is_immutable_feature_msr(u32 msr)
ARCH_CAP_SKIP_VMENTRY_L1DFLUSH | ARCH_CAP_SSB_NO | ARCH_CAP_MDS_NO | \
ARCH_CAP_PSCHANGE_MC_NO | ARCH_CAP_TSX_CTRL_MSR | ARCH_CAP_TAA_NO | \
ARCH_CAP_SBDR_SSDP_NO | ARCH_CAP_FBSDP_NO | ARCH_CAP_PSDP_NO | \
- ARCH_CAP_FB_CLEAR | ARCH_CAP_RRSBA | ARCH_CAP_PBRSB_NO | ARCH_CAP_GDS_NO)
+ ARCH_CAP_FB_CLEAR | ARCH_CAP_RRSBA | ARCH_CAP_PBRSB_NO | ARCH_CAP_GDS_NO | \
+ ARCH_CAP_RFDS_NO | ARCH_CAP_RFDS_CLEAR)
static u64 kvm_get_arch_capabilities(void)
{
@@ -1655,6 +1656,8 @@ static u64 kvm_get_arch_capabilities(void)
data |= ARCH_CAP_SSB_NO;
if (!boot_cpu_has_bug(X86_BUG_MDS))
data |= ARCH_CAP_MDS_NO;
+ if (!boot_cpu_has_bug(X86_BUG_RFDS))
+ data |= ARCH_CAP_RFDS_NO;
if (!boot_cpu_has(X86_FEATURE_RTM)) {
/*