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, USER_IN_DEF_DKIM_WL 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 2115AC4338F for ; Mon, 23 Aug 2021 16:39:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EAF23613DB for ; Mon, 23 Aug 2021 16:39:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230012AbhHWQjp (ORCPT ); Mon, 23 Aug 2021 12:39:45 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60194 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229632AbhHWQjo (ORCPT ); Mon, 23 Aug 2021 12:39:44 -0400 Received: from mail-lf1-x135.google.com (mail-lf1-x135.google.com [IPv6:2a00:1450:4864:20::135]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7F315C061575 for ; Mon, 23 Aug 2021 09:39:01 -0700 (PDT) Received: by mail-lf1-x135.google.com with SMTP id x27so39138515lfu.5 for ; Mon, 23 Aug 2021 09:39:01 -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=4p2SIjyr2T61r4gZ8TD43E2Uao8Waio9LnB3jyHODUE=; b=jvMPqPT6uKJeW+TjsUoIAtOe4uD6JvIFWw3aYKHJLLvdWLQPAWGYqpxVwopbcHIjgM O6V7IujoRlGqtRVeBXn8ykGLYnneWPaQSH5pk1L0nADq9hsJGcz7f2Ivnk4AJxWYSjtE LjL2Ob+lLVl0Rz4CzPoWzW3bq+is3uJJP3R3yi1aWV0izj4WtQ3SWOosmOFOJ5SSbYKV Htj/2MhbX9bUqjAcj1m5/zWoRWqIXZWHzbX9B/PmE6MyVHzJFte4y8EtchKz2XRTLxx9 Ho36w7rWf2fWeVrCMqHivcTQaGV3JC+dii1iuhyh2mC41OSUrhK0FM2antxIE49+FugA q86g== 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=4p2SIjyr2T61r4gZ8TD43E2Uao8Waio9LnB3jyHODUE=; b=Mb/PivHnnl4JH7e+6BBarrsPb5IRNov+W5+XT8pit4PNGt3zp7JPeC7Nn+rGWFRxmd +Kwcm5KXHhEIp6c4+GiHhQPWG8ywxSD6zrck3CNQ9N5nxbO3nUybetvwTDqP7Es68Vp4 dnx5eQKzTkmMHg8cz/uMeGQuCFjW8qVTeioqzXUerpU3LxBZa5BNWgeFD4CzzSVYpJvP 5RbiPH+opyvQGz7kZ09bBDGkoT2FL5glNI2/JwrWy69Ja5yuIhFyZVKUAzh/iLt6kBph jLhOI657s6qTBJbeE2AnV5QYW07IKqfvSjI/TftVZ+GvA4yxyVPl6UCGxwrmX3MrIqAM bpeQ== X-Gm-Message-State: AOAM530dWrxw91p0HhmmHFmzeuKyuLGiLJ6g50n+Wgjw6nO+7zolo5lC mNPeOSBkF+dLw5WKaDIlCp6tA1R74yZjzcVc09hKTA== X-Google-Smtp-Source: ABdhPJyjeHZmn5XGtrA0Q39V8wqH4+TOaO48osNYH5mbq8eiDnxY2tLi3q94bzKmYyHvMsclCPc1WIwWdULikunSLx0= X-Received: by 2002:a05:6512:3b0c:: with SMTP id f12mr5840024lfv.423.1629736739515; Mon, 23 Aug 2021 09:38:59 -0700 (PDT) MIME-Version: 1.0 References: <20210819154910.1064090-1-pgonda@google.com> <20210819154910.1064090-3-pgonda@google.com> In-Reply-To: From: Peter Gonda Date: Mon, 23 Aug 2021 10:38:48 -0600 Message-ID: Subject: Re: [PATCH 2/2 V4] KVM, SEV: Add support for SEV-ES intra host migration To: Marc Orr 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: kvm@vger.kernel.org On Fri, Aug 20, 2021 at 3:01 PM Marc Orr wrote: > > 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. Cleared in the next version and added a comment. We don't want to leave references for the source VM to edit the VMSA or GHCB after the migration. > > > + 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. Fixed thanks. > > > 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