linux-kernel - [PATCH 07/10] KVM: VMX: Clean up vmx_flush_tlb

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20200220204356.8837-8-sean.j.christopherson@intel.com>
Date:   Thu, 20 Feb 2020 12:43:53 -0800
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 07/10] 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.

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 5372a93e1727..906e9d9aa09e 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -2824,15 +2824,11 @@ 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