linux-kernel - [PATCH v3 15/37] KVM: VMX: Clean up vmx_flush_tlb

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Message-Id: <20200320212833.3507-16-sean.j.christopherson@intel.com>
Date:   Fri, 20 Mar 2020 14:28:11 -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, Ben Gardon <bgardon@...gle.com>,
        Junaid Shahid <junaids@...gle.com>,
        Liran Alon <liran.alon@...cle.com>,
        Boris Ostrovsky <boris.ostrovsky@...cle.com>,
        John Haxby <john.haxby@...cle.com>,
        Miaohe Lin <linmiaohe@...wei.com>,
        Tom Lendacky <thomas.lendacky@....com>
Subject: [PATCH v3 15/37] KVM: VMX: Clean up vmx_flush_tlb_gva()

Refactor vmx_flush_tlb_gva() to remove a superfluous local variable and
clean up its comment, which is oddly located below the code it is
commenting.

No functional change intended.

Reviewed-by: Vitaly Kuznetsov <vkuznets@...hat.com>
Reviewed-by: Paolo Bonzini <pbonzini@...hat.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@...el.com>
---
 arch/x86/kvm/vmx/vmx.c | 10 +++-------
 1 file changed, 3 insertions(+), 7 deletions(-)

diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 57c1cee58d18..43c0d4706f9a 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -2851,15 +2851,11 @@ static void exit_lmode(struct kvm_vcpu *vcpu)
 
 static void vmx_flush_tlb_gva(struct kvm_vcpu *vcpu, gva_t addr)
 {
-	int vpid = to_vmx(vcpu)->vpid;
-
-	vpid_sync_vcpu_addr(vpid, addr);
-
 	/*
-	 * If VPIDs are not supported or enabled, then the above is a no-op.
-	 * But we don't really need a TLB flush in that case anyway, because
-	 * each VM entry/exit includes an implicit flush when VPID is 0.
+	 * vpid_sync_vcpu_addr() is a nop if vmx->vpid==0, see the comment in
+	 * vmx_flush_tlb_guest() for an explanation of why this is ok.
 	 */
+	vpid_sync_vcpu_addr(to_vmx(vcpu)->vpid, addr);
 }
 
 static void vmx_flush_tlb_guest(struct kvm_vcpu *vcpu)
-- 
2.24.1