linux-kernel - [PATCH v3 1/5] KVM: VMX: Use precomputed MAXPHYADDR for RTIT base MSR check

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Date:   Thu, 24 Sep 2020 12:42:46 -0700
From:   Sean Christopherson <sean.j.christopherson@...el.com>
To:     Paolo Bonzini <pbonzini@...hat.com>
Cc:     Sean Christopherson <sean.j.christopherson@...el.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 v3 1/5] KVM: VMX: Use precomputed MAXPHYADDR for RTIT base MSR check

Use cpuid_maxphyaddr() instead of cpuid_query_maxphyaddr() for the
RTIT base MSR check.  There is no reason to recompute MAXPHYADDR as the
precomputed version is synchronized with CPUID updates, and
MSR_IA32_RTIT_OUTPUT_BASE is not written between stuffing CPUID and
refreshing vcpu->arch.maxphyaddr.

Signed-off-by: Sean Christopherson <sean.j.christopherson@...el.com>
---
 arch/x86/kvm/vmx/vmx.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 6f9a0c6d5dc5..be82da055fc4 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -147,7 +147,7 @@ module_param_named(preemption_timer, enable_preemption_timer, bool, S_IRUGO);
 	RTIT_STATUS_BYTECNT))
 
 #define MSR_IA32_RTIT_OUTPUT_BASE_MASK \
-	(~((1UL << cpuid_query_maxphyaddr(vcpu)) - 1) | 0x7f)
+	(~((1UL << cpuid_maxphyaddr(vcpu)) - 1) | 0x7f)
 
 /*
  * These 2 parameters are used to config the controls for Pause-Loop Exiting:
-- 
2.28.0