x86/cpufeatures: Add detection of L1D cache flush support.

336996-Speculative-Execution-Side-Channel-Mitigations.pdf defines a new MSR (IA32_FLUSH_CMD) which is detected by CPUID.7.EDX[28]=1 bit being set. This new MSR "gives software a way to invalidate structures with finer granularity than other architectual methods like WBINVD." A copy of this document is available at https://bugzilla.kernel.org/show_bug.cgi?id=199511 Signed-off-by: Konrad Rzeszutek Wilk <[email protected]> Signed-off-by: Thomas Gleixner <[email protected]>
adn770 · Jun 21, 2018 · 11e34e6 · 11e34e6
1 parent 1a7ed1b
commit 11e34e6
Showing 1 changed file with 1 addition and 0 deletions.
diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h
@@ -342,6 +342,7 @@
 #define X86_FEATURE_PCONFIG		(18*32+18) /* Intel PCONFIG */
 #define X86_FEATURE_SPEC_CTRL		(18*32+26) /* "" Speculation Control (IBRS + IBPB) */
 #define X86_FEATURE_INTEL_STIBP		(18*32+27) /* "" Single Thread Indirect Branch Predictors */
+#define X86_FEATURE_FLUSH_L1D		(18*32+28) /* Flush L1D cache */
 #define X86_FEATURE_ARCH_CAPABILITIES	(18*32+29) /* IA32_ARCH_CAPABILITIES MSR (Intel) */
 #define X86_FEATURE_SPEC_CTRL_SSBD	(18*32+31) /* "" Speculative Store Bypass Disable */