linux-kernel - [tip: x86/cpu] x86/cpu, kvm: Add the NO_NESTED_DATA

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Message-ID: <167472794735.4906.7514311983673336382.tip-bot2@tip-bot2>
Date:   Thu, 26 Jan 2023 10:12:27 -0000
From:   "tip-bot2 for Kim Phillips" <tip-bot2@...utronix.de>
To:     linux-tip-commits@...r.kernel.org
Cc:     Kim Phillips <kim.phillips@....com>,
        "Borislav Petkov (AMD)" <bp@...en8.de>,
        Sean Christopherson <seanjc@...gle.com>, x86@...nel.org,
        linux-kernel@...r.kernel.org
Subject: [tip: x86/cpu] x86/cpu, kvm: Add the NO_NESTED_DATA_BP feature

The following commit has been merged into the x86/cpu branch of tip:

Commit-ID:     a9dc9ec5a1fafc3d2fe7a7b594eefaeaccf89a6b
Gitweb:        https://git.kernel.org/tip/a9dc9ec5a1fafc3d2fe7a7b594eefaeaccf89a6b
Author:        Kim Phillips <kim.phillips@....com>
AuthorDate:    Tue, 24 Jan 2023 10:33:14 -06:00
Committer:     Borislav Petkov (AMD) <bp@...en8.de>
CommitterDate: Wed, 25 Jan 2023 12:36:34 +01:00

x86/cpu, kvm: Add the NO_NESTED_DATA_BP feature

The "Processor ignores nested data breakpoints" feature was being
open-coded for KVM.  Add the feature to its newly introduced CPUID leaf
0x80000021 EAX proper.

Signed-off-by: Kim Phillips <kim.phillips@....com>
Signed-off-by: Borislav Petkov (AMD) <bp@...en8.de>
Acked-by: Sean Christopherson <seanjc@...gle.com>
Link: https://lore.kernel.org/r/20230124163319.2277355-4-kim.phillips@amd.com
---
 arch/x86/include/asm/cpufeatures.h | 3 +++
 arch/x86/kvm/cpuid.c               | 2 +-
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h
index b890058..1b2d40a 100644
--- a/arch/x86/include/asm/cpufeatures.h
+++ b/arch/x86/include/asm/cpufeatures.h
@@ -427,6 +427,9 @@
 #define X86_FEATURE_V_TSC_AUX		(19*32+ 9) /* "" Virtual TSC_AUX */
 #define X86_FEATURE_SME_COHERENT	(19*32+10) /* "" AMD hardware-enforced cache coherency */
 
+/* AMD-defined Extended Feature 2 EAX, CPUID level 0x80000021 (EAX), word 20 */
+#define X86_FEATURE_NO_NESTED_DATA_BP	(20*32+ 0) /* "" No Nested Data Breakpoints */
+
 /*
  * BUG word(s)
  */
diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index f3edc35..aa3a6dc 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -742,7 +742,7 @@ void kvm_set_cpu_caps(void)
 		F(SME_COHERENT));
 
 	kvm_cpu_cap_mask(CPUID_8000_0021_EAX,
-		BIT(0) /* NO_NESTED_DATA_BP */ |
+		F(NO_NESTED_DATA_BP) |
 		BIT(2) /* LFENCE Always serializing */ | 0 /* SmmPgCfgLock */ |
 		BIT(6) /* NULL_SEL_CLR_BASE */ | 0 /* PrefetchCtlMsr */
 	);