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 X-Spam-Level: X-Spam-Status: No, score=-9.0 required=3.0 tests=BAYES_00,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id BCF44C4338F for ; Tue, 27 Jul 2021 17:51:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A326C60F57 for ; Tue, 27 Jul 2021 17:51:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229607AbhG0Rvg (ORCPT ); Tue, 27 Jul 2021 13:51:36 -0400 Received: from mail-wm1-f49.google.com ([209.85.128.49]:34305 "EHLO mail-wm1-f49.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229593AbhG0Rvg (ORCPT ); Tue, 27 Jul 2021 13:51:36 -0400 Received: by mail-wm1-f49.google.com with SMTP id l4-20020a05600c1d04b02902506f89ad2dso2389220wms.1; Tue, 27 Jul 2021 10:51:34 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=LwYScmPim6tE/MDgrbNvahN0e/2bkCVHKdvM2oDO2hU=; b=MtrhHyH1EXKfrApBmzExmtJ81J/XnuL7XiVCbcmvQKkxG+hXLKeZCmEfNXGbpWjY62 rX13lbYIsJ/+Vp4+lD3YnCoytkiz5++QgdO+fDn6ZGS1+kIuDLeXuiNl/IKOyg9N95uf SVFif8+8w+kXY8FGi+ldJGBX/CFY38eq6OxTKW+1PkVtzYqhLO5WD+qx+VMcMLC4wiif AH9neasCeL8+g+0ajfeGUCBXy5aAgSJeREzCcpD3EWxxdevIgqSwRMVBP0dSP4FQn7oH fYJWzZn5H/nH92iR/BIOKOCREACoR7ect04U+4QEKzLd4XWDXYhkT++jEwMxLnIyB0c7 3aDQ== X-Gm-Message-State: AOAM531zNZGoisjifNMTs2SH0cvfMU2nLGYTxVgKFB3dppdtTMB3ZUGo Bdxv3EC3fS5ttfEZIFz7YP4= X-Google-Smtp-Source: ABdhPJy+SrPjL/YKIxWhTGnciEmNbBdAW4RbjazaOxiclSAaBLaCvL9GcuSp5o4NuE7F0px1tOP/ug== X-Received: by 2002:a05:600c:4308:: with SMTP id p8mr5485552wme.45.1627408294068; Tue, 27 Jul 2021 10:51:34 -0700 (PDT) Received: from liuwe-devbox-debian-v2 ([51.145.34.42]) by smtp.gmail.com with ESMTPSA id q22sm3675211wmc.16.2021.07.27.10.51.33 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 27 Jul 2021 10:51:33 -0700 (PDT) Date: Tue, 27 Jul 2021 17:51:31 +0000 From: Wei Liu To: Praveen Kumar Cc: linux-hyperv@vger.kernel.org, linux-kernel@vger.kernel.org, kys@microsoft.com, haiyangz@microsoft.com, sthemmin@microsoft.com, wei.liu@kernel.org, decui@microsoft.com, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, x86@kernel.org, hpa@zytor.com, viremana@linux.microsoft.com, sunilmut@microsoft.com, nunodasneves@linux.microsoft.com Subject: Re: [PATCH v3] hyperv: root partition faults writing to VP ASSIST MSR PAGE Message-ID: <20210727175131.364fxm667marijdk@liuwe-devbox-debian-v2> References: <20210727104044.28078-1-kumarpraveen@linux.microsoft.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210727104044.28078-1-kumarpraveen@linux.microsoft.com> Precedence: bulk List-ID: X-Mailing-List: linux-hyperv@vger.kernel.org On Tue, Jul 27, 2021 at 04:10:44PM +0530, Praveen Kumar wrote: [...] > > @@ -170,9 +185,21 @@ static int hv_cpu_die(unsigned int cpu) > > hv_common_cpu_die(cpu); > > - if (hv_vp_assist_page && hv_vp_assist_page[cpu]) > + if (hv_vp_assist_page && hv_vp_assist_page[cpu]) { > wrmsrl(HV_X64_MSR_VP_ASSIST_PAGE, 0); > The content of the MSR should be preserved; otherwise you hit the same fault for root kernel. Wei.