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=-18.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,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 8DD6DC11F66 for ; Tue, 13 Jul 2021 20:13:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 764A06128E for ; Tue, 13 Jul 2021 20:13:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234997AbhGMUQE (ORCPT ); Tue, 13 Jul 2021 16:16:04 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38474 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234394AbhGMUQD (ORCPT ); Tue, 13 Jul 2021 16:16:03 -0400 Received: from mail-lj1-x22b.google.com (mail-lj1-x22b.google.com [IPv6:2a00:1450:4864:20::22b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5C956C0613DD for ; Tue, 13 Jul 2021 13:13:12 -0700 (PDT) Received: by mail-lj1-x22b.google.com with SMTP id r16so31851048ljk.9 for ; Tue, 13 Jul 2021 13:13:12 -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=euiefEzk8mTeEXe4b+xrYgYoRjWy4AZgIK0NfHWQQzY=; b=f3/XcZVE2NMeiY6ih5O52kTDCfLHjzpuTfJBCpCgGZamAJrHdECI2vw1aPCvj85xPW GPLJD9mFbQyPfKWlUL3z1d2IiBEfeuvFNrPcl5wfRwg6EWlrdaLa4v9wZ9GOmJ4VxWVI n68Gqak1aavAXeg2LaGOp4LZjxSUCNY2rIBUO+1hhyq9jP/kYmzSj76eTWuh+2j1jFSz /fmZWjXUzVH6tZdgLyA0XG78IhPkV2PefuU0PmnFa3Uk5Q0e6Qaeo5XusHH+xealSh8a /DTI3MYAzeKRMimRNk+JNxEcRKDgSqrFqSINEGR3Jq1Vn7W+mAcudwgOEW3mbrmhc5R8 RblQ== 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=euiefEzk8mTeEXe4b+xrYgYoRjWy4AZgIK0NfHWQQzY=; b=fLrjwcsUv7ab16UKxX7hOGXiEDIVgwuOBzf2QAa+YLG6MSHNN9xKl16uMCmj53OIua wJqr4Z+GzKng3kBYUFRaL+5PfUrJE+dEITU/YvekhqrDhMkLrQdMsvd3nv6pVtD5CjA0 XWU/oUMcPxerKs1kmMfWcDpKJlHv0T0Wo/b5FHpJW5TPU6MnNUnldK0BNh3kXqSacOBQ SNQlrP4uoRY9Mja2MWcDN47VMIiHQmcFCd8yb4oRK4yud12jKPLYToTYHgCufJNLWgLj 5sufVHKByRwxljw2omdU4OE/ReYPYVpWNR/YqfwIA5iyJBoyVOJ7g7LAKgVqM7qRczGq 979A== X-Gm-Message-State: AOAM531LqbjuJXQSklCpFDEnF9s8wvycUs19h0FQEB52+4HG0aU87Ikz 2c52CsAlJicvUwDB3GO49NoS9GLmg3Pzm+5oN0H+mg== X-Google-Smtp-Source: ABdhPJyNecPrGapneKA1aOeM7OZOTvb3YKLrvCDt7UITwo7dlhUBX/NySFVBTXbe1XxtZKoE87yfxNJFq+FbvmNiPjE= X-Received: by 2002:a2e:8110:: with SMTP id d16mr5731777ljg.42.1626207190335; Tue, 13 Jul 2021 13:13:10 -0700 (PDT) MIME-Version: 1.0 References: <20210621163118.1040170-1-pgonda@google.com> <20210621163118.1040170-3-pgonda@google.com> <3f4a1b67-f426-5101-1e07-9f948e529d34@amd.com> In-Reply-To: <3f4a1b67-f426-5101-1e07-9f948e529d34@amd.com> From: Peter Gonda Date: Tue, 13 Jul 2021 14:12:58 -0600 Message-ID: Subject: Re: [PATCH 2/3] KVM, SEV: Add support for SEV local migration To: Brijesh Singh Cc: kvm list , Lars Bull , Paolo Bonzini , Sean Christopherson , David Rientjes , "Dr . David Alan Gilbert" , 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 Thanks for reviewing Brijesh! Seanjc@ said he would comment so I'll lump your suggestions and his into the V2. On Mon, Jul 12, 2021 at 3:09 PM Brijesh Singh wrote: > > > > On 6/21/21 11:31 AM, Peter Gonda wrote: > > > + if (!sev_guest(kvm)) > > + return -ENOTTY; > > + > > + if (sev->es_active) > > + return -EPERM; > > + > > + if (sev->info_token != 0) > > + return -EEXIST; > > + > > + if (copy_from_user(¶ms, (void __user *)(uintptr_t)argp->data, > > + sizeof(params))) > > + return -EFAULT; > > + > > + entry = kzalloc(sizeof(*entry), GFP_KERNEL); > > + if (!entry) > > + return -ENOMEM; > > + > > + entry->asid = sev->asid; > > + entry->handle = sev->handle; > > + entry->pages_locked = sev->pages_locked; > > + entry->misc_cg = sev->misc_cg; > > + > > + INIT_LIST_HEAD(&entry->regions_list); > > + list_replace_init(&sev->regions_list, &entry->regions_list); > > I believe the entry->regions_list will be NULL if the command is called > before the memory regions are registered. The quesiton is, do you need > to check whether for a valid sev->handle (i.e, LAUNCH_START is done)? Makes sense to add a check for LAUNCH_START by checking sev->handle, I'll add that in V2. Would it also make sense to add similar checks to ioctls like launch update, measure, and finish? If so I can send a separate patch to add those checks. > > > > + > > /* Userspace wants to query session length. */ > > static int > > __sev_send_start_query_session_length(struct kvm *kvm, struct kvm_sev_cmd *argp, > > @@ -1513,6 +1711,18 @@ int svm_mem_enc_op(struct kvm *kvm, void __user *argp) > > goto out; > > } > > > > + /* > > + * If this VM has started exporting its SEV contents to another VM, > > + * it's not allowed to do any more SEV operations that may modify the > > + * SEV state. > > + */ > > + if (to_kvm_svm(kvm)->sev_info.info_token && > > + sev_cmd.id != KVM_SEV_DBG_ENCRYPT && > > + sev_cmd.id != KVM_SEV_DBG_DECRYPT) { > > + r = -EPERM; > > + goto out; > > + } > > Maybe move this check in a function so that it can later extended for > SEV-SNP (cmd ids for the debug is different). > > Something like: > > static bool is_local_mig_active(struct kvm *) > { > .... > } Will do! > > Once the migration range hypercall is merged, we also need to preserve > any metadata memory maintained by KVM for the unencrypted ranges. OK. Any suggestions on how to manage these impending conflicts. Are those almost ready and I should build these patches on top of those or what would you suggest? > > -Brijesh