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([2001:b07:6468:f312:c8dd:75d4:99ab:290a]) by smtp.gmail.com with ESMTPSA id q18sm19326723wmc.7.2021.10.25.08.57.40 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 25 Oct 2021 08:57:41 -0700 (PDT) Message-ID: Date: Mon, 25 Oct 2021 17:57:39 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.1.0 Subject: Re: [PATCH v2 37/43] KVM: SVM: Unconditionally mark AVIC as running on vCPU load (with APICv) Content-Language: en-US To: Sean Christopherson Cc: Marc Zyngier , Huacai Chen , Aleksandar Markovic , Paul Mackerras , Anup Patel , Paul Walmsley , Palmer Dabbelt , Albert Ou , Christian Borntraeger , Janosch Frank , James Morse , Alexandru Elisei , Suzuki K Poulose , Atish Patra , David Hildenbrand , Cornelia Huck , Claudio Imbrenda , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, linux-mips@vger.kernel.org, kvm@vger.kernel.org, kvm-ppc@vger.kernel.org, kvm-riscv@lists.infradead.org, linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, David Matlack , Oliver Upton , Jing Zhang References: <20211009021236.4122790-1-seanjc@google.com> <20211009021236.4122790-38-seanjc@google.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 25/10/21 17:48, Sean Christopherson wrote: > On Mon, Oct 25, 2021, Paolo Bonzini wrote: >> On 09/10/21 04:12, Sean Christopherson wrote: >>> + /* TODO: Document why the unblocking path checks for updates. */ >> >> Is that a riddle or what? :) > > Yes? I haven't been able to figure out why the unblocking path explicitly > checks and handles an APICv update. > Challenge accepted. In the original code, it was because without it avic_vcpu_load would do nothing, and nothing would update the IS_RUNNING flag. It shouldn't be necessary anymore since commit df7e4827c549 ("KVM: SVM: call avic_vcpu_load/avic_vcpu_put when enabling/disabling AVIC", 2021-08-20), where svm_refresh_apicv_exec_ctrl takes care of the avic_vcpu_load on the next VMRUN. Paolo 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6D28DC433F5 for ; Mon, 25 Oct 2021 15:57:57 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 310FB60EBD for ; Mon, 25 Oct 2021 15:57:57 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 310FB60EBD Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:Content-Type: Content-Transfer-Encoding:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:From:References:Cc:To:Subject: MIME-Version:Date:Message-ID:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=Ulez+sOAvzHi1OPCZoqr5qANZIbdhw8w735QvSTMR+E=; b=yEZyYmki5JAFXL FPa5uPouAzP3DX+jplOMAwf+pT57pvbd00eezgq5VPsdszoMdcPUAyXHeaj5JL2zVlPaKx57IixpU SON0bBAOULtoDdusx35RRPXasQrhsUq/Cph0NQr3cA+h3UK6kEr+pABQF3SZyP/nTRZigGfDnG44f gJ5MTNrwI4MkHvCK/aJ+gyUf19YSFTtJp2Hx02T21lhcxZiILuzb9MvaDo2qi+tiMaysw0oKgXPd5 a6jRfP8c9yaXiwWqnL1BOjFnXxbemJIhh/OpGACyLg+KRwhgPrfhlz1j0hxUYhEBx2cTPWDMoRO1y yXfjiwSryqso55+1469Q==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1mf2M9-00GwVN-69; Mon, 25 Oct 2021 15:57:49 +0000 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1mf2M6-00GwU6-FV for linux-riscv@lists.infradead.org; Mon, 25 Oct 2021 15:57:47 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1635177465; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=MCI+8dQa/U6UbsL5gbfoLfO4WAaUcQYsMls2gbgANLc=; b=d5fBTafVsle7rlJGdQNqsXio/F72LOo2tQDiG5d8pnwkxANT5JCfW5IUfmH6YSz68+2OF2 lAqa8X9kupvqCKBQnpBdImbNZ51Ze4GOgRx9pIDgn+blDJGJf+IJq2SdetOZO6PUGA7yLL C/y2qcIGdg5S5spV4/4PRPahunXd4rs= Received: from mail-wm1-f72.google.com (mail-wm1-f72.google.com [209.85.128.72]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-324-LPN-gly-O7i24YpzkyTusA-1; Mon, 25 Oct 2021 11:57:44 -0400 X-MC-Unique: LPN-gly-O7i24YpzkyTusA-1 Received: by mail-wm1-f72.google.com with SMTP id f63-20020a1c3842000000b0032a621260deso3666738wma.8 for ; Mon, 25 Oct 2021 08:57:43 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:message-id:date:mime-version:user-agent:subject :content-language:to:cc:references:from:in-reply-to :content-transfer-encoding; bh=MCI+8dQa/U6UbsL5gbfoLfO4WAaUcQYsMls2gbgANLc=; b=FbJpkDuUMT3v2JlrGi2i1HZJOHMl1BLFq/fXeuyD13dH1fwYHxF0rPQAFmT/r7kls0 zlyK7ewUFmtBzzmho2b5M9BDQ/C7K5lFQcOUhfj3dCF7NlW6LhY80AIDNST3pZ0xLo48 to6Fypb1F6TBxxKU8kdDLBpR4G88JX4RCsszDw6FtxfM8SGA3D5QgpMGNSn6bovK7ygD IgUrkpFcRtVaNrzJ5Yrvy+WQ7nNWsZEpLnK1gREfv7cue9hBPkEfRuWB0TEQFRMnDoQ+ mTrj4LXzLkJkliGd+8WVE0bdQAo+QAEPLFR5BXKe0tYFQKFStbCdc6oo1WcjP/5sSzH/ 0RNg== X-Gm-Message-State: AOAM530cCvjKEHdDX8TYJQqgKKOuRWk0xfb/ogMS+ddnzgJKwHbjObYv aUxKsiH429duXmDzUbvbWb1F32OmuysWSuONM39DNzDpsoeDTb1atobOlJw8Jc/I4xc2wv8CY/d 4m92aoNDU81BI90U4nOGcMvibVn79 X-Received: by 2002:a1c:ac86:: with SMTP id v128mr20601935wme.3.1635177462565; Mon, 25 Oct 2021 08:57:42 -0700 (PDT) X-Google-Smtp-Source: ABdhPJxTyw0n0fr/6Esub1t61IkuBW8xshfxOi+C+/6mJQnqMkQEum3VdKMAAqawVcu+H74+uWZwJg== X-Received: by 2002:a1c:ac86:: with SMTP id v128mr20601909wme.3.1635177462345; Mon, 25 Oct 2021 08:57:42 -0700 (PDT) Received: from ?IPV6:2001:b07:6468:f312:c8dd:75d4:99ab:290a? ([2001:b07:6468:f312:c8dd:75d4:99ab:290a]) by smtp.gmail.com with ESMTPSA id q18sm19326723wmc.7.2021.10.25.08.57.40 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 25 Oct 2021 08:57:41 -0700 (PDT) Message-ID: Date: Mon, 25 Oct 2021 17:57:39 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.1.0 Subject: Re: [PATCH v2 37/43] KVM: SVM: Unconditionally mark AVIC as running on vCPU load (with APICv) To: Sean Christopherson Cc: Marc Zyngier , Huacai Chen , Aleksandar Markovic , Paul Mackerras , Anup Patel , Paul Walmsley , Palmer Dabbelt , Albert Ou , Christian Borntraeger , Janosch Frank , James Morse , Alexandru Elisei , Suzuki K Poulose , Atish Patra , David Hildenbrand , Cornelia Huck , Claudio Imbrenda , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, linux-mips@vger.kernel.org, kvm@vger.kernel.org, kvm-ppc@vger.kernel.org, kvm-riscv@lists.infradead.org, linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, David Matlack , Oliver Upton , Jing Zhang References: <20211009021236.4122790-1-seanjc@google.com> <20211009021236.4122790-38-seanjc@google.com> From: Paolo Bonzini In-Reply-To: Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=pbonzini@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Language: en-US X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20211025_085746_682231_04A6BCA9 X-CRM114-Status: UNSURE ( 9.62 ) X-CRM114-Notice: Please train this message. X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org On 25/10/21 17:48, Sean Christopherson wrote: > On Mon, Oct 25, 2021, Paolo Bonzini wrote: >> On 09/10/21 04:12, Sean Christopherson wrote: >>> + /* TODO: Document why the unblocking path checks for updates. */ >> >> Is that a riddle or what? :) > > Yes? I haven't been able to figure out why the unblocking path explicitly > checks and handles an APICv update. > Challenge accepted. In the original code, it was because without it avic_vcpu_load would do nothing, and nothing would update the IS_RUNNING flag. It shouldn't be necessary anymore since commit df7e4827c549 ("KVM: SVM: call avic_vcpu_load/avic_vcpu_put when enabling/disabling AVIC", 2021-08-20), where svm_refresh_apicv_exec_ctrl takes care of the avic_vcpu_load on the next VMRUN. Paolo _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 471D6C433F5 for ; Mon, 25 Oct 2021 15:57:50 +0000 (UTC) Received: from mm01.cs.columbia.edu (mm01.cs.columbia.edu [128.59.11.253]) by mail.kernel.org (Postfix) with ESMTP id AF80A60F6F for ; Mon, 25 Oct 2021 15:57:49 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org AF80A60F6F Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=lists.cs.columbia.edu Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 446FA4B08E; Mon, 25 Oct 2021 11:57:49 -0400 (EDT) X-Virus-Scanned: at lists.cs.columbia.edu Authentication-Results: mm01.cs.columbia.edu (amavisd-new); dkim=softfail (fail, message has been altered) header.i=@redhat.com Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id yaIlezAlARQw; Mon, 25 Oct 2021 11:57:47 -0400 (EDT) Received: from mm01.cs.columbia.edu (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id DBF404B0DF; Mon, 25 Oct 2021 11:57:47 -0400 (EDT) Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id E98FA4B08E for ; Mon, 25 Oct 2021 11:57:46 -0400 (EDT) X-Virus-Scanned: at lists.cs.columbia.edu Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id gaKHF6g9FplX for ; Mon, 25 Oct 2021 11:57:45 -0400 (EDT) Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 6973A4ACC9 for ; Mon, 25 Oct 2021 11:57:45 -0400 (EDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1635177465; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=MCI+8dQa/U6UbsL5gbfoLfO4WAaUcQYsMls2gbgANLc=; b=d5fBTafVsle7rlJGdQNqsXio/F72LOo2tQDiG5d8pnwkxANT5JCfW5IUfmH6YSz68+2OF2 lAqa8X9kupvqCKBQnpBdImbNZ51Ze4GOgRx9pIDgn+blDJGJf+IJq2SdetOZO6PUGA7yLL C/y2qcIGdg5S5spV4/4PRPahunXd4rs= Received: from mail-wm1-f71.google.com (mail-wm1-f71.google.com [209.85.128.71]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-562-ADF35c9PNGGyvNDOz0HFOQ-1; Mon, 25 Oct 2021 11:57:43 -0400 X-MC-Unique: ADF35c9PNGGyvNDOz0HFOQ-1 Received: by mail-wm1-f71.google.com with SMTP id s3-20020a1ca903000000b0032326edebe1so3685399wme.2 for ; Mon, 25 Oct 2021 08:57:43 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:message-id:date:mime-version:user-agent:subject :content-language:to:cc:references:from:in-reply-to :content-transfer-encoding; bh=MCI+8dQa/U6UbsL5gbfoLfO4WAaUcQYsMls2gbgANLc=; b=SNPvdbITLxZB5o5AH6qJkNPJ9ArDpg4eVLgqJne9jcPEiRICs/lwjwd40vfYTIsng6 wQLz59KDG8fMgX4jCg0jrW9Kz9Y6vn1I1yCvYVV/o2cqv66XDOkyPRIpROZ4vsd9c0af WnDibPhdPSX+e5FTXNEnKAkPo9M+eGK8GPNW4FQkmP+F8bUEVGLZpwEnZ8TWI1SQGZ7I MMLAx2pZKfVD9jgU+tuMocNRs3tWarF6p0IV9n8OeYCbtr75R/xCF8XYpCyKMcm/CFQ/ ynepXKT51T7AX83R5t35HhJIz1YgysTLL6bBEVGWot8sgqjdeNSpn3ejvzBS8w42yk7j XqHg== X-Gm-Message-State: AOAM530O6lf7tEnvEqWNfZOnGNPENpVpoEijvVIwtTouq8fnWylyXEYx 1BnDX08WHvuVvkfk61yyngZ3OXyRj+M6XSpfGiXuVCXxEvJTNohzHuLkw2vd+7Xpw+9PJtcO7D/ uJDICBvVfoDf66cLj/Zbe2lgp X-Received: by 2002:a1c:ac86:: with SMTP id v128mr20601944wme.3.1635177462567; Mon, 25 Oct 2021 08:57:42 -0700 (PDT) X-Google-Smtp-Source: ABdhPJxTyw0n0fr/6Esub1t61IkuBW8xshfxOi+C+/6mJQnqMkQEum3VdKMAAqawVcu+H74+uWZwJg== X-Received: by 2002:a1c:ac86:: with SMTP id v128mr20601909wme.3.1635177462345; Mon, 25 Oct 2021 08:57:42 -0700 (PDT) Received: from ?IPV6:2001:b07:6468:f312:c8dd:75d4:99ab:290a? ([2001:b07:6468:f312:c8dd:75d4:99ab:290a]) by smtp.gmail.com with ESMTPSA id q18sm19326723wmc.7.2021.10.25.08.57.40 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 25 Oct 2021 08:57:41 -0700 (PDT) Message-ID: Date: Mon, 25 Oct 2021 17:57:39 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.1.0 Subject: Re: [PATCH v2 37/43] KVM: SVM: Unconditionally mark AVIC as running on vCPU load (with APICv) To: Sean Christopherson References: <20211009021236.4122790-1-seanjc@google.com> <20211009021236.4122790-38-seanjc@google.com> From: Paolo Bonzini In-Reply-To: Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=pbonzini@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Language: en-US Cc: Cornelia Huck , Wanpeng Li , kvm@vger.kernel.org, David Hildenbrand , linux-kernel@vger.kernel.org, Paul Mackerras , Atish Patra , linux-riscv@lists.infradead.org, Claudio Imbrenda , kvmarm@lists.cs.columbia.edu, Janosch Frank , Marc Zyngier , Joerg Roedel , Huacai Chen , Christian Borntraeger , Aleksandar Markovic , Albert Ou , kvm-ppc@vger.kernel.org, Paul Walmsley , David Matlack , linux-arm-kernel@lists.infradead.org, Jim Mattson , Anup Patel , linux-mips@vger.kernel.org, Palmer Dabbelt , kvm-riscv@lists.infradead.org, Vitaly Kuznetsov X-BeenThere: kvmarm@lists.cs.columbia.edu X-Mailman-Version: 2.1.14 Precedence: list List-Id: Where KVM/ARM decisions are made List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu On 25/10/21 17:48, Sean Christopherson wrote: > On Mon, Oct 25, 2021, Paolo Bonzini wrote: >> On 09/10/21 04:12, Sean Christopherson wrote: >>> + /* TODO: Document why the unblocking path checks for updates. */ >> >> Is that a riddle or what? :) > > Yes? I haven't been able to figure out why the unblocking path explicitly > checks and handles an APICv update. > Challenge accepted. In the original code, it was because without it avic_vcpu_load would do nothing, and nothing would update the IS_RUNNING flag. It shouldn't be necessary anymore since commit df7e4827c549 ("KVM: SVM: call avic_vcpu_load/avic_vcpu_put when enabling/disabling AVIC", 2021-08-20), where svm_refresh_apicv_exec_ctrl takes care of the avic_vcpu_load on the next VMRUN. Paolo _______________________________________________ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7A372C433EF for ; Mon, 25 Oct 2021 15:59:07 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 49BF060C49 for ; Mon, 25 Oct 2021 15:59:07 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 49BF060C49 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:Content-Type: Content-Transfer-Encoding:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:From:References:Cc:To:Subject: MIME-Version:Date:Message-ID:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=G0DYopPwsYOMBswW/q5TiynmphiBhd8fzJ6HHN6OvT4=; b=I31oJNZ8gIPMRc FxBYDDIjG6pxQ0Rc0i1Fe+vY24XPINoxzMp1GkzBHPlZgXw6riGpdo3yzCXcBtQotgSEvW2Yyto3q CF7Pn/Hv5HmRAnM20sY90sj/XMdBjXLFGoQFOaGP1UUmsRYRZOhoc4bPkIzsPUsrcILXgh2hG6uaX m07qWsawvCv81qck0tZuuA0+VtcPH7wA/kKHU55yvGD4ZHODWVR9Zzs7y+3iz2lxh31lhF4qezETA lpGxJwO7jXbPyew9I+EXxHeACqEfegGb1EO6ZOxkkwNRjhkertaaVdGgpLqDtmHOWxi6OxFBTHLvm jdyT2+/moTTNv0bN+tGg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1mf2MC-00GwW5-29; Mon, 25 Oct 2021 15:57:52 +0000 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1mf2M8-00GwUl-1q for linux-arm-kernel@lists.infradead.org; Mon, 25 Oct 2021 15:57:49 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1635177467; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=MCI+8dQa/U6UbsL5gbfoLfO4WAaUcQYsMls2gbgANLc=; b=OmLBQk2beG56tGmWj5yadmLP7AT00DqcEevbe2wRSZyWima0tMHOqTIHZsr+8sv/8rDvKV di119IgwTizVgj8FQj8oyQTsMLHcx7rQjAbM7l2M0PNBuCUpu53vDbRgqBJlbZLo1GSZvZ KivoyAsQv37qjzo8G1LPq78ilXmvm28= Received: from mail-wm1-f72.google.com (mail-wm1-f72.google.com [209.85.128.72]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-324-tAT4rQSGMUmlv8UGYZNW2A-1; Mon, 25 Oct 2021 11:57:43 -0400 X-MC-Unique: tAT4rQSGMUmlv8UGYZNW2A-1 Received: by mail-wm1-f72.google.com with SMTP id c18-20020a1c9a12000000b0032caecbbe54so1890023wme.3 for ; Mon, 25 Oct 2021 08:57:43 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:message-id:date:mime-version:user-agent:subject :content-language:to:cc:references:from:in-reply-to :content-transfer-encoding; bh=MCI+8dQa/U6UbsL5gbfoLfO4WAaUcQYsMls2gbgANLc=; b=KxmUBUc5ZcKoURBATFfHl58DNjdPQ2HVy45rvWEDfJUKyXthlKytfNHBtHbuW3W+12 zqkDKkxpaVYq8PW6DcOIaAoaJ6PhvxprNlAgNVD/hR7yolI4uA3b8RAT/Ts00QDp6hz0 BT4DRJ/5DKKb6RpYHj/JL3NcBzOPl/B6BbrUxbENUhohawfLBsHkAhfwd3PYkvT8ZGjW wTeaiWgON/s6EkmSnr2x1daEsA1HOHNvOTF2wBVMfYi1+Mab+WFHsDWmtAL6POirFfza jNpIF4sFf1Fq8ASLyBZewCn8IjfiQt4CNwginQOgguBfS5bOj/kMug7/Y94ey3UYzd7e kIog== X-Gm-Message-State: AOAM533mZg+WodtGswUgOt9InBQNOsAV0eaYHcmSlz86E1DdUE77t4+M kLhoJaJQJjzGyaDc6YEDj5ktnWhWXY289UDTBfV2/5QWt394vvjEGt+k6bMetYBY4s+5zw/SO0u VZQRYvcnUMGky2RY4F4Ty4uTTFNTBq7oTtH0= X-Received: by 2002:a1c:ac86:: with SMTP id v128mr20601940wme.3.1635177462566; Mon, 25 Oct 2021 08:57:42 -0700 (PDT) X-Google-Smtp-Source: ABdhPJxTyw0n0fr/6Esub1t61IkuBW8xshfxOi+C+/6mJQnqMkQEum3VdKMAAqawVcu+H74+uWZwJg== X-Received: by 2002:a1c:ac86:: with SMTP id v128mr20601909wme.3.1635177462345; Mon, 25 Oct 2021 08:57:42 -0700 (PDT) Received: from ?IPV6:2001:b07:6468:f312:c8dd:75d4:99ab:290a? ([2001:b07:6468:f312:c8dd:75d4:99ab:290a]) by smtp.gmail.com with ESMTPSA id q18sm19326723wmc.7.2021.10.25.08.57.40 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 25 Oct 2021 08:57:41 -0700 (PDT) Message-ID: Date: Mon, 25 Oct 2021 17:57:39 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.1.0 Subject: Re: [PATCH v2 37/43] KVM: SVM: Unconditionally mark AVIC as running on vCPU load (with APICv) To: Sean Christopherson Cc: Marc Zyngier , Huacai Chen , Aleksandar Markovic , Paul Mackerras , Anup Patel , Paul Walmsley , Palmer Dabbelt , Albert Ou , Christian Borntraeger , Janosch Frank , James Morse , Alexandru Elisei , Suzuki K Poulose , Atish Patra , David Hildenbrand , Cornelia Huck , Claudio Imbrenda , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, linux-mips@vger.kernel.org, kvm@vger.kernel.org, kvm-ppc@vger.kernel.org, kvm-riscv@lists.infradead.org, linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, David Matlack , Oliver Upton , Jing Zhang References: <20211009021236.4122790-1-seanjc@google.com> <20211009021236.4122790-38-seanjc@google.com> From: Paolo Bonzini In-Reply-To: Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=pbonzini@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Language: en-US X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20211025_085748_178754_99541DE9 X-CRM114-Status: GOOD ( 11.14 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 25/10/21 17:48, Sean Christopherson wrote: > On Mon, Oct 25, 2021, Paolo Bonzini wrote: >> On 09/10/21 04:12, Sean Christopherson wrote: >>> + /* TODO: Document why the unblocking path checks for updates. */ >> >> Is that a riddle or what? :) > > Yes? I haven't been able to figure out why the unblocking path explicitly > checks and handles an APICv update. > Challenge accepted. In the original code, it was because without it avic_vcpu_load would do nothing, and nothing would update the IS_RUNNING flag. It shouldn't be necessary anymore since commit df7e4827c549 ("KVM: SVM: call avic_vcpu_load/avic_vcpu_put when enabling/disabling AVIC", 2021-08-20), where svm_refresh_apicv_exec_ctrl takes care of the avic_vcpu_load on the next VMRUN. Paolo _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paolo Bonzini Date: Mon, 25 Oct 2021 15:57:39 +0000 Subject: Re: [PATCH v2 37/43] KVM: SVM: Unconditionally mark AVIC as running on vCPU load (with APICv) Message-Id: List-Id: References: <20211009021236.4122790-1-seanjc@google.com> <20211009021236.4122790-38-seanjc@google.com> In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Sean Christopherson Cc: Marc Zyngier , Huacai Chen , Aleksandar Markovic , Paul Mackerras , Anup Patel , Paul Walmsley , Palmer Dabbelt , Albert Ou , Christian Borntraeger , Janosch Frank , James Morse , Alexandru Elisei , Suzuki K Poulose , Atish Patra , David Hildenbrand , Cornelia Huck , Claudio Imbrenda , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, linux-mips@vger.kernel.org, kvm@vger.kernel.org, kvm-ppc@vger.kernel.org, kvm-riscv@lists.infradead.org, linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, David Matlack , Oliver Upton , Jing Zhang On 25/10/21 17:48, Sean Christopherson wrote: > On Mon, Oct 25, 2021, Paolo Bonzini wrote: >> On 09/10/21 04:12, Sean Christopherson wrote: >>> + /* TODO: Document why the unblocking path checks for updates. */ >> >> Is that a riddle or what? :) > > Yes? I haven't been able to figure out why the unblocking path explicitly > checks and handles an APICv update. > Challenge accepted. In the original code, it was because without it avic_vcpu_load would do nothing, and nothing would update the IS_RUNNING flag. It shouldn't be necessary anymore since commit df7e4827c549 ("KVM: SVM: call avic_vcpu_load/avic_vcpu_put when enabling/disabling AVIC", 2021-08-20), where svm_refresh_apicv_exec_ctrl takes care of the avic_vcpu_load on the next VMRUN. Paolo