linux-kernel - [PATCH 04/23] KVM: x86: Add IBPB

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Message-ID: <79d5f5914fb42c2c62418ffbcd78f138645ded21.1692919072.git.jpoimboe@kernel.org>
Date:   Fri, 25 Aug 2023 00:01:35 -0700
From:   Josh Poimboeuf <jpoimboe@...nel.org>
To:     x86@...nel.org
Cc:     linux-kernel@...r.kernel.org, Borislav Petkov <bp@...en8.de>,
        Peter Zijlstra <peterz@...radead.org>,
        Babu Moger <babu.moger@....com>,
        Paolo Bonzini <pbonzini@...hat.com>,
        Sean Christopherson <seanjc@...gle.com>, David.Kaplan@....com,
        Andrew Cooper <andrew.cooper3@...rix.com>,
        Nikolay Borisov <nik.borisov@...e.com>,
        gregkh@...uxfoundation.org, Thomas Gleixner <tglx@...utronix.de>
Subject: [PATCH 04/23] KVM: x86: Add IBPB_BRTYPE support

Add support for the IBPB_BRTYPE CPUID flag, which indicates that IBPB
includes branch type prediction flushing.

Signed-off-by: Josh Poimboeuf <jpoimboe@...nel.org>
---
 arch/x86/kvm/cpuid.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index d3432687c9e6..c65f3ff1c79d 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -729,8 +729,8 @@ void kvm_set_cpu_caps(void)
 		F(NULL_SEL_CLR_BASE) | F(AUTOIBRS) | 0 /* PrefetchCtlMsr */
 	);
 
-	if (cpu_feature_enabled(X86_FEATURE_SRSO_NO))
-		kvm_cpu_cap_set(X86_FEATURE_SRSO_NO);
+	kvm_cpu_cap_check_and_set(X86_FEATURE_IBPB_BRTYPE);
+	kvm_cpu_cap_check_and_set(X86_FEATURE_SRSO_NO);
 
 	kvm_cpu_cap_init_kvm_defined(CPUID_8000_0022_EAX,
 		F(PERFMON_V2)
-- 
2.41.0