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 45B6FC433EF for ; Thu, 7 Apr 2022 16:16:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244986AbiDGQSI (ORCPT ); Thu, 7 Apr 2022 12:18:08 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57158 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1345702AbiDGQRl (ORCPT ); Thu, 7 Apr 2022 12:17:41 -0400 Received: from mail-pj1-x102d.google.com (mail-pj1-x102d.google.com [IPv6:2607:f8b0:4864:20::102d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A5205D0816 for ; Thu, 7 Apr 2022 09:15:40 -0700 (PDT) Received: by mail-pj1-x102d.google.com with SMTP id e8-20020a17090a118800b001cb13402ea2so2251816pja.0 for ; Thu, 07 Apr 2022 09:15:40 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=pjmFekv8jDwjPEFoUA7K+aTQqc3Lv+ZZUAGbkfR0nhI=; b=REXPQfxvAcns+qRUBa9udhfUz0fCCn+7TO+QFD3ATUcXTx2Phkp/eVe23ASEjcWXQV QCWUG/TN5909B7ITNddW45R2t5Nn0L+HnPDKPIAE3TUvrTe5ALH9E9uCBu4wPVENnyH4 I4+BTTaYUn07QJvrBv/XnCbWfOc3DDPUx5d4JMCCWsjCQ24YHLivS+aulwih+wIp+p9u 3E6wGA6ouQzwZoH1JuHVWifo6VTDovIKz/hOCbFL2BjA2R0lADQVaflz5XofhNWQAGnt 6a3OMKtKv8JeWvf8pr1wp8lAbHgf06ChlK+lTBHq3gYvaVUXkSr03+NcDP3LuuGPgkHp y0jg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=pjmFekv8jDwjPEFoUA7K+aTQqc3Lv+ZZUAGbkfR0nhI=; b=tMTdcOMV5T7tvKSXs5/vEmNpwdKk5z49IpljwLoaUD09ZPSIMotPrG5ymPQRe2f6qP X55I2BFK/5FiCsw7MrI3J+RMXbfy0eyXQm8KcHYXDLCqHD9JjujolmoUEmoG/DQcNR8C sxneJrbGz+TZ9F5Iex1l5QH7zJ8EtffK/hmLewV7cGdUVu6XsvFnz3OZf/6110/RbIIz seBOhEtmmVgQfldEtoKY6oyz4s/byghNihpidbPkoEbJlW1BYa/vme8kZu1sdmhlwDnx 4yW/wW/NmB4NbsN3CV6MwEo3w8ND4Fnr2cnr6rR3Is20KoSS1La66gMy50d4fah4x5k1 3drw== X-Gm-Message-State: AOAM532PeGLmOsU6YZc9GZneDgkBWi/mmQ+d8f9qWeaZfYOI0UmPlb3H FETS/RLfK9IDxYREfRP2kRxPzQ== X-Google-Smtp-Source: ABdhPJyyrQ71dJva+gEqAi8WgQYtWeT60fGgpZLIS3NYZpUvh4J8u8RD/czp1XiotgUuR8s75Zz2zQ== X-Received: by 2002:a17:902:d4c1:b0:153:d493:3f1 with SMTP id o1-20020a170902d4c100b00153d49303f1mr14704352plg.102.1649348139813; Thu, 07 Apr 2022 09:15:39 -0700 (PDT) Received: from google.com (157.214.185.35.bc.googleusercontent.com. [35.185.214.157]) by smtp.gmail.com with ESMTPSA id h21-20020a056a001a5500b004fb71896e49sm22593891pfv.25.2022.04.07.09.15.39 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 07 Apr 2022 09:15:39 -0700 (PDT) Date: Thu, 7 Apr 2022 16:15:35 +0000 From: Sean Christopherson To: Vitaly Kuznetsov Cc: kvm@vger.kernel.org, Paolo Bonzini , Wanpeng Li , Jim Mattson , Naresh Kamboju , Maxim Levitsky , linux-kernel@vger.kernel.org Subject: Re: [PATCH] KVM: x86: hyper-v: Avoid writing to TSC page without an active vCPU Message-ID: References: <20220407154754.939923-1-vkuznets@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220407154754.939923-1-vkuznets@redhat.com> Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Thu, Apr 07, 2022, Vitaly Kuznetsov wrote: > diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h > index 676705ad1e23..3460bcd75bf2 100644 > --- a/arch/x86/include/asm/kvm_host.h > +++ b/arch/x86/include/asm/kvm_host.h > @@ -979,10 +979,10 @@ enum hv_tsc_page_status { > HV_TSC_PAGE_GUEST_CHANGED, > /* TSC page MSR was written by KVM userspace, update pending */ > HV_TSC_PAGE_HOST_CHANGED, > + /* TSC page needs to be updated due to internal KVM changes */ > + HV_TSC_PAGE_KVM_CHANGED, Why add KVM_CHANGED? I don't see any reason to differentiate between userspace and KVM, and using KVM_CHANGED for the kvm_vm_ioctl_set_clock() case is wrong as that is very much a userspace initiated update, not a KVM update. > /* TSC page was properly set up and is currently active */ > HV_TSC_PAGE_SET, > - /* TSC page is currently being updated and therefore is inactive */ > - HV_TSC_PAGE_UPDATING, > /* TSC page was set up with an inaccessible GPA */ > HV_TSC_PAGE_BROKEN, > };