From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id CBF10C433EF for ; Tue, 8 Mar 2022 16:43:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1348163AbiCHQoR (ORCPT ); Tue, 8 Mar 2022 11:44:17 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46472 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237545AbiCHQoM (ORCPT ); Tue, 8 Mar 2022 11:44:12 -0500 Received: from mail-ej1-x62b.google.com (mail-ej1-x62b.google.com [IPv6:2a00:1450:4864:20::62b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4057A24BDA; Tue, 8 Mar 2022 08:43:12 -0800 (PST) Received: by mail-ej1-x62b.google.com with SMTP id d10so40510097eje.10; Tue, 08 Mar 2022 08:43:12 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=sender:message-id:date:mime-version:user-agent:subject :content-language:to:cc:references:from:in-reply-to :content-transfer-encoding; bh=qCwmsr6oXjLssymqT/qnNYZlcUrE07F4Pfsz9zDexWY=; b=AsJ3ni/sXixNRzUwef/sZOye7j1wWGf96xnlH+VbPvzisqEpn6pZ5H6dZ72D/a4jWU KNw5mnRYWCF++dTjqZ/2wqL9H9PONtPzg1NpC4gp+jiFPudTFzyNOzbVxczx3x/Dipip CmtYUJJRefXGzQBgicVm5Fn4Gtuz21jAdsV9qhjmJXa1/Y519SJjwe3pwYbZ8GCJU6Bl 7jXM0rJjflCooB8sMKu0cSHvMlM71PqBMxtEnlcStaeU8eJp1jJXKpUPHoX/e438AYtX MuFSYvO5Ph1dCaKTm7ogdV7olUr+MgYh3PeEtwSV/Ed3WzJ0bMBy2/+GWe4S/Fj1LA4C dOcw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:sender:message-id:date:mime-version:user-agent :subject:content-language:to:cc:references:from:in-reply-to :content-transfer-encoding; bh=qCwmsr6oXjLssymqT/qnNYZlcUrE07F4Pfsz9zDexWY=; b=JI/C3ZhgFIhosxOLHhNXPJtInBbw70kcx0JiCoTHZCeGrAlzfhXRN4vukZXbQ6Bb4d e+xRqQ1xU4UhI2NRjdNa4Wx2+rMtZ8uF8R2sdT1kh4lbm5tbATLde0FJSKfkb9GtnrE0 5pA//lA3yxaDDBCS10NZ0JQfD4eI16Q5tBQSvn4jB9oaKgBUxLFq4q+UYeRctkjnM+ZL IPrU031oF9e5IL1wyMPVzu9kfXeS2JEK06ZfcR9T8guqfCWRNb8erK8QBwdHrFaRHKZr K0qA4xjwCjcnb2F+Tc3yMxhxhu/zzrczVJoaSp5hOIqcQxZb7+i3Wmx6ymfia6DzdiZe AfHQ== X-Gm-Message-State: AOAM531+P+0WcnQq4ZPTljsrpvWRDfVmtyxu1rPpLKQFPFl8bXgF8kMi y1i7MxiOlBBN1ufJbKXJQJ4= X-Google-Smtp-Source: ABdhPJwgvxEvidx9EZtknDVlSJ3dOKj3gRaE5pH3wsPsth2fTUjpxQdHXLLhuz+5Pbw6cDus3dw5aw== X-Received: by 2002:a17:907:9495:b0:6da:9602:3ec6 with SMTP id dm21-20020a170907949500b006da96023ec6mr14198272ejc.589.1646757790664; Tue, 08 Mar 2022 08:43:10 -0800 (PST) Received: from ?IPV6:2001:b07:6468:f312:c8dd:75d4:99ab:290a? ([2001:b07:6468:f312:c8dd:75d4:99ab:290a]) by smtp.googlemail.com with ESMTPSA id v4-20020a170906338400b006d5aca9fc80sm6027445eja.106.2022.03.08.08.43.09 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 08 Mar 2022 08:43:09 -0800 (PST) Sender: Paolo Bonzini Message-ID: <96ff1628-eeb2-4d12-f4eb-287dd8fc9948@redhat.com> Date: Tue, 8 Mar 2022 17:43:08 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.5.0 Subject: Re: [PATCH v2 01/25] KVM: x86/mmu: avoid indirect call for get_cr3 Content-Language: en-US To: Sean Christopherson Cc: linux-kernel@vger.kernel.org, kvm@vger.kernel.org, dmatlack@google.com References: <20220221162243.683208-1-pbonzini@redhat.com> <20220221162243.683208-2-pbonzini@redhat.com> <2652c27e-ce8c-eb40-1979-9fe732aa9085@redhat.com> From: Paolo Bonzini In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 3/8/22 17:32, Sean Christopherson wrote: > > Aha! An idea that would provide line of sight to avoiding retpoline in all cases > once we use static_call() for nested_ops, which I really want to do... Drop the > mmu hook entirely and replace it with: > > static inline kvm_mmu_get_guest_pgd(struct kvm_vcpu *vcpu) > { > if (!mmu_is_nested(vcpu)) > return kvm_read_cr3(vcpu); > else > return kvm_x86_ops.nested_ops->get_guest_pgd(vcpu); > } Makes sense, but I think you mean static inline unsigned long kvm_mmu_get_guest_pgd(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu) { if (unlikely(vcpu == &vcpu->arch.guest_mmu)) return kvm_x86_ops.nested_ops->get_guest_pgd(vcpu); else return kvm_read_cr3(vcpu); } ? Paolo