[PATCH 22/23] x86/cpufeatures: Add the Virtual SPEC_CTRL feature

From: Paolo Bonzini
Date: Tue Mar 02 2021 - 17:38:33 EST


From: Babu Moger <babu.moger@xxxxxxx>

Newer AMD processors have a feature to virtualize the use of the
SPEC_CTRL MSR. Presence of this feature is indicated via CPUID
function 0x8000000A_EDX[20]: GuestSpecCtrl. When present, the
SPEC_CTRL MSR is automatically virtualized.

Signed-off-by: Babu Moger <babu.moger@xxxxxxx>
Acked-by: Borislav Petkov <bp@xxxxxxx>
Message-Id: <161188100272.28787.4097272856384825024.stgit@bmoger-ubuntu>
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
---
arch/x86/include/asm/cpufeatures.h | 1 +
1 file changed, 1 insertion(+)

diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h
index f1957b3c8e4e..9ac7ad4d8239 100644
--- a/arch/x86/include/asm/cpufeatures.h
+++ b/arch/x86/include/asm/cpufeatures.h
@@ -338,6 +338,7 @@
#define X86_FEATURE_AVIC (15*32+13) /* Virtual Interrupt Controller */
#define X86_FEATURE_V_VMSAVE_VMLOAD (15*32+15) /* Virtual VMSAVE VMLOAD */
#define X86_FEATURE_VGIF (15*32+16) /* Virtual GIF */
+#define X86_FEATURE_V_SPEC_CTRL (15*32+20) /* Virtual SPEC_CTRL */
#define X86_FEATURE_SVME_ADDR_CHK (15*32+28) /* "" SVME addr check */

/* Intel-defined CPU features, CPUID level 0x00000007:0 (ECX), word 16 */
--
2.26.2