linux-kernel - [PATCH 3/5] KVM: VMX: RTIT_CTL_BRANCH_EN has no dependency on other CPUID bit

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Date:   Tue, 24 Aug 2021 19:07:41 +0800
From:   Xiaoyao Li <xiaoyao.li@...el.com>
To:     Paolo Bonzini <pbonzini@...hat.com>
Cc:     Xiaoyao Li <xiaoyao.li@...el.com>,
        Sean Christopherson <seanjc@...gle.com>,
        Vitaly Kuznetsov <vkuznets@...hat.com>,
        Wanpeng Li <wanpengli@...cent.com>,
        Jim Mattson <jmattson@...gle.com>,
        Joerg Roedel <joro@...tes.org>, kvm@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: [PATCH 3/5] KVM: VMX: RTIT_CTL_BRANCH_EN has no dependency on other CPUID bit

Per Intel SDM, RTIT_CTL_BRANCH_EN bit has no dependency on any CPUID
leaf 0x14.

Signed-off-by: Xiaoyao Li <xiaoyao.li@...el.com>
---
 arch/x86/kvm/vmx/vmx.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 7ed96c460661..4a70a6d2f442 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -7116,7 +7116,8 @@ static void update_intel_pt_cfg(struct kvm_vcpu *vcpu)
 
 	/* Initialize and clear the no dependency bits */
 	vmx->pt_desc.ctl_bitmask = ~(RTIT_CTL_TRACEEN | RTIT_CTL_OS |
-			RTIT_CTL_USR | RTIT_CTL_TSC_EN | RTIT_CTL_DISRETC);
+			RTIT_CTL_USR | RTIT_CTL_TSC_EN | RTIT_CTL_DISRETC |
+			RTIT_CTL_BRANCH_EN);
 
 	/*
 	 * If CPUID.(EAX=14H,ECX=0):EBX[0]=1 CR3Filter can be set otherwise
@@ -7134,12 +7135,11 @@ static void update_intel_pt_cfg(struct kvm_vcpu *vcpu)
 				RTIT_CTL_CYC_THRESH | RTIT_CTL_PSB_FREQ);
 
 	/*
-	 * If CPUID.(EAX=14H,ECX=0):EBX[3]=1 MTCEn BranchEn and
-	 * MTCFreq can be set
+	 * If CPUID.(EAX=14H,ECX=0):EBX[3]=1 MTCEn and MTCFreq can be set
 	 */
 	if (intel_pt_validate_cap(vmx->pt_desc.caps, PT_CAP_mtc))
 		vmx->pt_desc.ctl_bitmask &= ~(RTIT_CTL_MTC_EN |
-				RTIT_CTL_BRANCH_EN | RTIT_CTL_MTC_RANGE);
+					      RTIT_CTL_MTC_RANGE);
 
 	/* If CPUID.(EAX=14H,ECX=0):EBX[4]=1 FUPonPTW and PTWEn can be set */
 	if (intel_pt_validate_cap(vmx->pt_desc.caps, PT_CAP_ptwrite))
-- 
2.27.0