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=-13.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_IN_DEF_DKIM_WL autolearn=no 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 041C4C433DB for ; Sat, 23 Jan 2021 00:30:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C9B4323AF8 for ; Sat, 23 Jan 2021 00:30:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726506AbhAWAaT (ORCPT ); Fri, 22 Jan 2021 19:30:19 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40770 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726287AbhAWAaH (ORCPT ); Fri, 22 Jan 2021 19:30:07 -0500 Received: from mail-pl1-x629.google.com (mail-pl1-x629.google.com [IPv6:2607:f8b0:4864:20::629]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4E91EC06174A for ; Fri, 22 Jan 2021 16:29:27 -0800 (PST) Received: by mail-pl1-x629.google.com with SMTP id 31so4202645plb.10 for ; Fri, 22 Jan 2021 16:29:27 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=JYV4rqk7TIJOls4aIYOUfgRgv+FJ3Bybe0z5zvt0O7Q=; b=El3nUfopMydRnCl9GOyvd5cxCak0al5FXcbT6BiVzxoyts5vmsuAa4eUFOTzbUIlp6 GVZzkro3xnR49VaHW3drFk4t+/eTDBPxIjl2nOT+xZuAUlCe/B3SHZcdpSaqwXDL6ykg 7mG55vp4pb0wuZPlFnuhZswUdQMi/EAN2WTlOT52gAcWuhs18ENKphCjt8ZjDAR92x23 pkT/xCeFIoZKW074PTlX7eKG4SfBVFwwAFKg7sgZRJa/Q3rtMD6P3FbVGkvlrD2iC3Pf ZEkBHjaSvF+Ql1/7LKzJAkGxyd6jjZNx4EYGtkRUs9dRdm8Kk70rZ8oHGX5INX0JbOLb PsyQ== 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=JYV4rqk7TIJOls4aIYOUfgRgv+FJ3Bybe0z5zvt0O7Q=; b=DyWPho7aYMARbykTfCBENQsIa5p4xm1+Sk8+vzkWSSWTLgHbcmzQyLk6cKM0xsKV7I UwncLAodzuKrwV20+aChnO8oJVI0RpOzgkegUA57uEKMbEcLH1F3erkOZbnFIDDWlydS fH2Fe4s+FwbFJ37kIZVU1BH3JyY5LBmdHKjr9wkqLVt3d538XP1fIUk10zHyGa1APx+Z 3Bl3LbpPi3Ln2Mw7hnueokneUEl/wBgaYDqGBh3Hqr7STZAbcc+2igypfA+SxCYHFvF5 Gz7IZS6FOQ/XC31SR0TkqxnuYDerdHuEV0gc02Kx5Nh+scPFoyIGr6ld+sEqosrhpVKS OF5g== X-Gm-Message-State: AOAM532XTmY7jAVC6ZXouJL6jwxbzh6kjFlBpu4ldzXvaZV0CUSYlgSZ +la9tSHHj4zjwx9k7RioOPBNaA== X-Google-Smtp-Source: ABdhPJyoONkEm2J9ITe4V6jvZN8X3b2s30ELlnoOthsB+837AdhIk2k9C1PL1ntyue/tv/K7/zZibA== X-Received: by 2002:a17:90b:313:: with SMTP id ay19mr2089571pjb.184.1611361766735; Fri, 22 Jan 2021 16:29:26 -0800 (PST) Received: from google.com ([2620:15c:f:10:1ea0:b8ff:fe73:50f5]) by smtp.gmail.com with ESMTPSA id x125sm9323072pgb.35.2021.01.22.16.29.25 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 22 Jan 2021 16:29:26 -0800 (PST) Date: Fri, 22 Jan 2021 16:29:19 -0800 From: Sean Christopherson To: Tom Lendacky Cc: Paolo Bonzini , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Brijesh Singh Subject: Re: [PATCH 3/3] KVM: SVM: Sync GPRs to the GHCB only after VMGEXIT Message-ID: References: <20210122235049.3107620-1-seanjc@google.com> <20210122235049.3107620-4-seanjc@google.com> <0d8e9d63-1fe9-af08-dae9-edd80083e940@amd.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <0d8e9d63-1fe9-af08-dae9-edd80083e940@amd.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jan 22, 2021, Tom Lendacky wrote: > On 1/22/21 5:50 PM, Sean Christopherson wrote: > > Sync GPRs to the GHCB on VMRUN only if a sync is needed, i.e. if the > > previous exit was a VMGEXIT and the guest is expecting some data back. > > > > The start of sev_es_sync_to_ghcb() checks if the GHCB has been mapped, which > only occurs on VMGEXIT, and exits early if not. And sev_es_sync_from_ghcb() > is only called if the GHCB has been successfully mapped. The only thing in > between is sev_es_validate_vmgexit(), which will terminate the VM on error. > So I don't think this patch is needed. Ah, nice! Yep, this can be dropped. Thanks!