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 16A00C433F5 for ; Fri, 11 Mar 2022 02:45:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1345755AbiCKCqj (ORCPT ); Thu, 10 Mar 2022 21:46:39 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60100 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1345695AbiCKCqh (ORCPT ); Thu, 10 Mar 2022 21:46:37 -0500 Received: from mail-pj1-x1034.google.com (mail-pj1-x1034.google.com [IPv6:2607:f8b0:4864:20::1034]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 926CA1A6171 for ; Thu, 10 Mar 2022 18:45:35 -0800 (PST) Received: by mail-pj1-x1034.google.com with SMTP id m11-20020a17090a7f8b00b001beef6143a8so6945980pjl.4 for ; Thu, 10 Mar 2022 18:45:35 -0800 (PST) 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=47i1jj48gdh3ugZzKcCuj8iKYQMqov+4VOJuq+ofx1c=; b=EwsUUWwZsnckxs2a4ZBw8a9ZffO4o4ww26MBKNDANGiNO/8noFSkJHVfuhyqhy8B9p nkdYIVNy0ZeeYNaq6/8qCbC73vC+7gT4s54Si/VYAwu2ccJOTzFZLv/1+RDvHD7Jj+JO Ghg5aguK+r4EFNoq+afjB8BGxdwZYevnaXojB3+Ei4UbsMnM0xjAkSbGH3KaaVENaUxK +atuZ5iPE6xfqgYHjOZxBqODlc1/a52i6vibGuuzNSJh0ae5b3NCyoFc/urowJ/Vk0Sb xTaCBBJL9wd6HpZ+2eW2mWyGEPZjY4AjV7U7yTQJUcbjlZHlJghWHx1ahg9GEv+E+zNk Zb+Q== 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=47i1jj48gdh3ugZzKcCuj8iKYQMqov+4VOJuq+ofx1c=; b=pgoi0DjsP3VNBuLzEni17s7g7XtjGY9Yh7tFspUU8Wvrd9GFG8U849nEcTWvI6A01v 4NOUOXoh+s1WOMUdyd3Be8kMfKXDhvH/Zy5602MvXUSz/wbyui4utFnxKOZoaoH7h71A O6IQNVVn5dGEN+PkVbJC1oZ4qkRcU3faXqU13E0ICdbRqARiyBAzk8rgtkD0Gg7yw7VF IJcCdXMOn39uz8+tkWIqGbQUuFYbLu5gh6vmv6e/AjBJ0ZhqH6R2+bi6Fi4mDrpGiVRy AIy7BNue1LpPE8OtjMexeqoCtgBMkgTKLT3wLR8a6lh5hV7NP12OWpzuI3GOVkBA0Nig FDvg== X-Gm-Message-State: AOAM532SthwqWVxK4idFDVaIGx2I2oTTALRqIcUNAei7JI9W9pScgSZy 0f/Rkj2CEs9D7TZllyIEvKR8BA== X-Google-Smtp-Source: ABdhPJxflJ3gDTpRwiLKqo8WKXUUCVF0L/GEoBXyngNxZCllT97T7WemfWcoM3I53cQCENyD2VayNQ== X-Received: by 2002:a17:90a:cce:b0:1bf:6387:30d9 with SMTP id 14-20020a17090a0cce00b001bf638730d9mr19593474pjt.196.1646966734760; Thu, 10 Mar 2022 18:45:34 -0800 (PST) Received: from google.com (157.214.185.35.bc.googleusercontent.com. [35.185.214.157]) by smtp.gmail.com with ESMTPSA id g1-20020aa796a1000000b004f788397831sm693790pfk.217.2022.03.10.18.45.33 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 10 Mar 2022 18:45:34 -0800 (PST) Date: Fri, 11 Mar 2022 02:45:30 +0000 From: Sean Christopherson To: Chenyi Qiang Cc: Paolo Bonzini , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , Xiaoyao Li , kvm@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v4 1/3] KVM: X86: Extend KVM_SET_VCPU_EVENTS to inject a SHUTDOWN event Message-ID: References: <20220310084001.10235-1-chenyi.qiang@intel.com> <20220310084001.10235-2-chenyi.qiang@intel.com> <5f2012f7-80ba-c034-a098-cede4184a125@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5f2012f7-80ba-c034-a098-cede4184a125@intel.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Mar 11, 2022, Chenyi Qiang wrote: > > On 3/11/2022 1:43 AM, Sean Christopherson wrote: > > On Thu, Mar 10, 2022, Chenyi Qiang wrote: > > > @@ -4976,6 +4977,9 @@ static int kvm_vcpu_ioctl_x86_set_vcpu_events(struct kvm_vcpu *vcpu, > > > } > > > } > > > + if (events->flags & KVM_VCPUEVENT_SHUTDOWN) > > > + kvm_make_request(KVM_REQ_TRIPLE_FAULT, vcpu); > > > > Huh. I think we need to make this bidirection and add it to get_vcpu_events() > > as well, and treat it as a bug fix. In direct triple fault cases, i.e. hardware > > detected and morphed to VM-Exit, KVM will never lose the triple fault. But for > > triple faults sythesized by KVM, e.g. the RSM path or nested_vmx_abort(), if KVM > > exits to userspace before the request is serviced, userspace could migrate the > > VM and lose the triple fault. > > Good catch. Then the name of this definition is not quit fit now. How about > changing to KVM_VCPUEVENT_SYTHESIZED_TRIPLE_FAULT? I don't think the SYNTHESIZED part is necessary. KVM doesn't make that distinction for other events/exceptions, and whose to say that KVM won't end up with a case where a "real" triple fault needs to be migrated. I do have a slight preference for KVM_VCPUEVENT_TRIPLE_FAULT or KVM_VCPUEVENT_SHUTDOWN, but it's a very slight preference.