Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751616AbdHRMg7 (ORCPT ); Fri, 18 Aug 2017 08:36:59 -0400 Received: from mx1.redhat.com ([209.132.183.28]:54626 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750913AbdHRMg5 (ORCPT ); Fri, 18 Aug 2017 08:36:57 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com AD88A15552 Authentication-Results: ext-mx05.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx05.extmail.prod.ext.phx2.redhat.com; spf=fail smtp.mailfrom=rkrcmar@redhat.com Date: Fri, 18 Aug 2017 14:36:50 +0200 From: Radim =?utf-8?B?S3LEjW3DocWZ?= To: David Hildenbrand Cc: Paolo Bonzini , linux-kernel@vger.kernel.org, kvm@vger.kernel.org, wanpeng.li@hotmail.com, Brijesh Singh Subject: Re: [PATCH 2/3] KVM: x86: Avoid guest page table walk when gpa_available is set Message-ID: <20170818123649.GB20100@flask> References: <1502987818-24065-1-git-send-email-pbonzini@redhat.com> <1502987818-24065-3-git-send-email-pbonzini@redhat.com> <97f78603-3007-2418-653a-58a0d33a0523@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <97f78603-3007-2418-653a-58a0d33a0523@redhat.com> X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.29]); Fri, 18 Aug 2017 12:36:57 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1078 Lines: 31 2017-08-18 09:57+0200, David Hildenbrand: > > > +++ b/arch/x86/kvm/x86.c > > @@ -4657,25 +4657,18 @@ static int emulator_read_write_onepage(unsigned long addr, void *val, > > */ > > if (vcpu->arch.gpa_available && > > emulator_can_use_gpa(ctxt) && > > - vcpu_is_mmio_gpa(vcpu, addr, exception->address, write) && > > - (addr & ~PAGE_MASK) == (exception->address & ~PAGE_MASK)) { > > - gpa = exception->address; > > - goto mmio; > > + (addr & ~PAGE_MASK) == (vcpu->arch.gpa_val & ~PAGE_MASK)) { > > + gpa = vcpu->arch.gpa_val; > > + ret = vcpu_is_mmio_gpa(vcpu, addr, gpa, write); > > + } else { > > + ret = vcpu_mmio_gva_to_gpa(vcpu, addr, &gpa, exception, write); > > } > > > > - ret = vcpu_mmio_gva_to_gpa(vcpu, addr, &gpa, exception, write); > > - > > if (ret < 0) > > return X86EMUL_PROPAGATE_FAULT; > > just wondering if it makes sense to move this into the else branch (as > it logically only belongs to vcpu_mmio_gva_to_gpa) It does, I took the liberty to change that. > Reviewed-by: David Hildenbrand Thanks.