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=-23.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_IN_DEF_DKIM_WL autolearn=unavailable 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 D0928C432BE for ; Fri, 20 Aug 2021 21:01:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A902D60F45 for ; Fri, 20 Aug 2021 21:01:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239023AbhHTVBv (ORCPT ); Fri, 20 Aug 2021 17:01:51 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41424 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230282AbhHTVBs (ORCPT ); Fri, 20 Aug 2021 17:01:48 -0400 Received: from mail-qk1-x72f.google.com (mail-qk1-x72f.google.com [IPv6:2607:f8b0:4864:20::72f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0CFD1C061756 for ; Fri, 20 Aug 2021 14:01:10 -0700 (PDT) Received: by mail-qk1-x72f.google.com with SMTP id c10so9693159qko.11 for ; Fri, 20 Aug 2021 14:01:09 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=hFKLnnqi/Dpw7z7KzTGlV1/db6RzMAc6Y8UjXQLOhbQ=; b=tPH6w/D/mrob2wDKf+lpRu/LME/iVMMs0JKKxfzabgzD2zxn+xgFRLaQ+qwr3x7LlQ Lge5mhpT3wm29E8Y1MxpZRo171kRIxi3OCtpLkvqukQinmGoKWKrYxJdOm+sAd4oAT3W pOUx9B1X60E+y60laBmKZ7HlJJY0DQmlDxU68uG1bnT5+Wm+Js7uH1/tQ9anQuToNGSI 8Ub9cxNlYK2pzK/1n4N9Rj/LMGm7RQnbqIfvb0QFnFNlewYdvRTbAa3x2mJNSTdmFRsm ks2ItbfuyEaLUfbEi0YfFjoYTrTrCq9XLRRENZScd7PSPUWsxp65VxzT6CCjOyFGmsZK 7f0g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=hFKLnnqi/Dpw7z7KzTGlV1/db6RzMAc6Y8UjXQLOhbQ=; b=AVAPd9xidtMOBtrjcQ6BCn3y9jhjU86WrwDg05PWwn5AZKAYH6lK0kmDlcWaU3rU8u y1ChvXnD1ja/45N2TjRs2PdXImeFmGhwzoBJDs+X8Vxd54eRJHJJMeOpNnkH7QqHDA0C 1yD3gYLLaBx4xjAMh3IEMxWSC/dE7/lSNv3iPkzygs02dC7RIIcTuXBgX1OBp0jSdIP9 wQlbgNHD8TgcHX9Cr5RhCqD12aO47q/qnuiXW8ebNsi4bPCnmvTrjwGQesOgJ5iPtZ5I Docy82WNNnAEeGS5LOSem/v8j0djX8sRdsrGf0trD32cH3WGh7cS7Vy8tXX2nWzIQL8a sQSg== X-Gm-Message-State: AOAM530jKva85Wu0RqOQ7BP/n46vD8zfpfLtk+uB9e6teMrJuqFa5lgB vhY0NBFg4Waoa310kaI09E09XNNod8O61/7TRqJ1Hw== X-Google-Smtp-Source: ABdhPJwWnDBr7vwtUzWMyPt8C+NJaLfm4Oe/LTA5LuA5TmMpDI/Ii9Yncf/2/Q8qDG0GdVdi9qpPRlQEFlwCYbQq9VQ= X-Received: by 2002:a05:620a:204e:: with SMTP id d14mr10687840qka.147.1629493268884; Fri, 20 Aug 2021 14:01:08 -0700 (PDT) MIME-Version: 1.0 References: <20210819154910.1064090-1-pgonda@google.com> <20210819154910.1064090-3-pgonda@google.com> In-Reply-To: <20210819154910.1064090-3-pgonda@google.com> From: Marc Orr Date: Fri, 20 Aug 2021 14:00:57 -0700 Message-ID: Subject: Re: [PATCH 2/2 V4] KVM, SEV: Add support for SEV-ES intra host migration To: Peter Gonda Cc: kvm list , Paolo Bonzini , Sean Christopherson , David Rientjes , "Dr . David Alan Gilbert" , Brijesh Singh , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , Thomas Gleixner , Ingo Molnar , Borislav Petkov , "H. Peter Anvin" , linux-kernel@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Aug 19, 2021 at 8:49 AM Peter Gonda wrote: > > For SEV-ES to work with intra host migration the VMSAs, GHCB metadata, > and other SEV-ES info needs to be preserved along with the guest's > memory. > > Signed-off-by: Peter Gonda > Cc: Marc Orr > Cc: Paolo Bonzini > Cc: Sean Christopherson > Cc: David Rientjes > Cc: Dr. David Alan Gilbert > Cc: Brijesh Singh > Cc: Vitaly Kuznetsov > Cc: Wanpeng Li > Cc: Jim Mattson > Cc: Joerg Roedel > Cc: Thomas Gleixner > Cc: Ingo Molnar > Cc: Borislav Petkov > Cc: "H. Peter Anvin" > Cc: kvm@vger.kernel.org > Cc: linux-kernel@vger.kernel.org > --- > arch/x86/kvm/svm/sev.c | 58 +++++++++++++++++++++++++++++++++++++++--- > 1 file changed, 55 insertions(+), 3 deletions(-) > > diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c > index 2d98b56b6f8c..970d75c34e9a 100644 > --- a/arch/x86/kvm/svm/sev.c > +++ b/arch/x86/kvm/svm/sev.c > @@ -1554,6 +1554,53 @@ static void migrate_info_from(struct kvm_sev_info *dst, > list_replace_init(&src->regions_list, &dst->regions_list); > } > > +static int migrate_vmsa_from(struct kvm *dst, struct kvm *src) > +{ > + int i, num_vcpus; > + struct kvm_vcpu *dst_vcpu, *src_vcpu; > + struct vcpu_svm *dst_svm, *src_svm; > + > + num_vcpus = atomic_read(&dst->online_vcpus); > + if (num_vcpus != atomic_read(&src->online_vcpus)) { > + pr_warn_ratelimited( > + "Source and target VMs must have same number of vCPUs.\n"); > + return -EINVAL; > + } > + > + for (i = 0; i < num_vcpus; ++i) { > + src_vcpu = src->vcpus[i]; > + if (!src_vcpu->arch.guest_state_protected) { > + pr_warn_ratelimited( > + "Source ES VM vCPUs must have protected state.\n"); > + return -EINVAL; > + } > + } > + > + for (i = 0; i < num_vcpus; ++i) { > + src_vcpu = src->vcpus[i]; > + src_svm = to_svm(src_vcpu); > + dst_vcpu = dst->vcpus[i]; > + dst_svm = to_svm(dst_vcpu); > + > + dst_vcpu->vcpu_id = src_vcpu->vcpu_id; > + dst_svm->vmsa = src_svm->vmsa; > + src_svm->vmsa = NULL; > + dst_svm->ghcb = src_svm->ghcb; > + src_svm->ghcb = NULL; > + dst_svm->vmcb->control.ghcb_gpa = > + src_svm->vmcb->control.ghcb_gpa; Should we clear `src_svm->vmcb->control.ghcb_gpa`? (All the other fields in `srv_svm` that are copied are then cleared, except for this one.) Aside: Do we really need to clear all of the fields in `src_svm` after they're copied over? It might be worth adding a comment to explain why we're clearing them. It's not immediately obvious to me why we're doing that. > + dst_svm->ghcb_sa = src_svm->ghcb_sa; > + src_svm->ghcb_sa = NULL; > + dst_svm->ghcb_sa_len = src_svm->ghcb_sa_len; > + src_svm->ghcb_sa_len = 0; > + dst_svm->ghcb_sa_sync = src_svm->ghcb_sa_sync; > + src_svm->ghcb_sa_sync = false; > + dst_svm->ghcb_sa_free = src_svm->ghcb_sa_free; > + src_svm->ghcb_sa_free = false; > + } > + return 0; > +} > + > int svm_vm_migrate_from(struct kvm *kvm, unsigned int source_fd) > { > struct kvm_sev_info *dst_sev = &to_kvm_svm(kvm)->sev_info; > @@ -1565,7 +1612,7 @@ int svm_vm_migrate_from(struct kvm *kvm, unsigned int source_fd) > if (ret) > return ret; > > - if (!sev_guest(kvm) || sev_es_guest(kvm)) { > + if (!sev_guest(kvm)) { > ret = -EINVAL; > pr_warn_ratelimited("VM must be SEV enabled to migrate to.\n"); > goto out_unlock; > @@ -1589,15 +1636,20 @@ int svm_vm_migrate_from(struct kvm *kvm, unsigned int source_fd) > if (ret) > goto out_fput; > > - if (!sev_guest(source_kvm) || sev_es_guest(source_kvm)) { > + if (!sev_guest(source_kvm)) { > ret = -EINVAL; > pr_warn_ratelimited( > "Source VM must be SEV enabled to migrate from.\n"); > goto out_source; > } > > + if (sev_es_guest(kvm)) { > + ret = migrate_vmsa_from(kvm, source_kvm); > + if (ret) > + goto out_source; > + } > migrate_info_from(dst_sev, &to_kvm_svm(source_kvm)->sev_info); > - ret = 0; > + ret = 0; nit: looks like there's some space issue on this line. Since I believe this line was introduced in the previous patch, I wouldn't expect it to show up with a diff in patch #2. > out_source: > svm_unlock_after_migration(source_kvm); > -- > 2.33.0.rc1.237.g0d66db33f3-goog This patch looks good overall to me. Reviewed-by: Marc Orr