From patchwork Thu Sep 2 18:17:49 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Peter Gonda X-Patchwork-Id: 12472283 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=-26.3 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_AGENT_GIT,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 1B9BBC433F5 for ; Thu, 2 Sep 2021 18:18:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EC2B361051 for ; Thu, 2 Sep 2021 18:18:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1346965AbhIBSTG (ORCPT ); Thu, 2 Sep 2021 14:19:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45408 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1346926AbhIBSTC (ORCPT ); Thu, 2 Sep 2021 14:19:02 -0400 Received: from mail-qt1-x84a.google.com (mail-qt1-x84a.google.com [IPv6:2607:f8b0:4864:20::84a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4D95CC061757 for ; Thu, 2 Sep 2021 11:18:03 -0700 (PDT) Received: by mail-qt1-x84a.google.com with SMTP id c20-20020a05622a059400b002a0bb6f8d84so2565164qtb.15 for ; Thu, 02 Sep 2021 11:18:03 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=vi00j8i95gzlA2JogRJZOpEKy7t58Be6t0UyDx2Twqk=; b=FsTvb40Aj+T4ym0oiVLCWAsq5jfNDkcTytOs636elmul9FMTJv4kp2HcQsxIzYVrW+ 25WPhnvT6xyTqYFmU0pCL+PeZwUFDLcdltSQc7dud+C0cAOl0dYmxLqvSUok+xxZGLT2 naTrHubJFPMbPLFp/PiJ+cLz+dTEluC3zwAca+4fW2gWczn3sDFqq6/T4GrVvhAercAO nrhG2FrJIQ16x704qjfhY8+n3Zxp7arN0ensy3gllK+/8ZezdzWRY3bXCn0SzY4r3EET xQPNllwbwsYBzWnu9PsV3l9cRRcfCRCzbDiAYIL4GQ2uQyT25Qamlb0TWXsQj5zgg8J+ 2odg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=vi00j8i95gzlA2JogRJZOpEKy7t58Be6t0UyDx2Twqk=; b=YyZaWYsaewT7WK7wTd7LaFy0KnSZvEg3U3IukczQAFF3ZTMgubtkUmx2msR628V2aY KUsEDszsPxC8OWEd4gbK6QRLZobeveSO1Vk8v1peYRhSNT52SRu7FMDAgqfHcRhJZfEF RlJ0cS5i0Jz0BnU7QijsvUZ4xhQALATQgN9mSDGZ6VueHtU0bR1lW4DBan2E0BgxbgzE O01LzuPxOjyEFlLopMCy5b8sgLAwkYOfsGTy+c5105vAZ4gXvAvkB0Qov6QH/biIFZry 3PHBLai1OShTSfLJOZ6ouUwcOwrmWQefyDELvRZCWLs83O8H7O3TXX5wubxBIhr/7PfK oZgA== X-Gm-Message-State: AOAM531IPx/QHs7UfnzqPbVwMQ6W9Ofjk+ILifUMVwCHyay87FzLtM9w F0ngU1rETlZ9RaHacJIfbiZaMWTxROUsE9JQfRkAY0WE2cOtVdPWnCOqZncIgVKsStDPy1/HlMe ZYBgB3VtKlKsNl5zVEcdKKxEnKA/9TTJ1Qt76ZTdKaV2OXHxdxKCMyofCyQ== X-Google-Smtp-Source: ABdhPJwmXksaTZmuphP9pjyf9+v9VGtGSmw6GnSNPgp0UnKj7JA+2VkIMO6SK48I6OOwbVck8zNpVzKlZoE= X-Received: from pgonda1.kir.corp.google.com ([2620:15c:29:204:faf4:6e40:7b4e:999f]) (user=pgonda job=sendgmr) by 2002:a05:6214:b11:: with SMTP id u17mr4500603qvj.40.1630606682465; Thu, 02 Sep 2021 11:18:02 -0700 (PDT) Date: Thu, 2 Sep 2021 11:17:49 -0700 In-Reply-To: <20210902181751.252227-1-pgonda@google.com> Message-Id: <20210902181751.252227-2-pgonda@google.com> Mime-Version: 1.0 References: <20210902181751.252227-1-pgonda@google.com> X-Mailer: git-send-email 2.33.0.153.gba50c8fa24-goog Subject: [PATCH 1/3 V7] KVM, SEV: Add support for SEV intra host migration From: Peter Gonda To: kvm@vger.kernel.org Cc: Peter Gonda , Sean Christopherson , Marc Orr , Paolo Bonzini , 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 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org For SEV to work with intra host migration, contents of the SEV info struct such as the ASID (used to index the encryption key in the AMD SP) and the list of memory regions need to be transferred to the target VM. This change adds a commands for a target VMM to get a source SEV VM's sev info. The target is expected to be initialized (sev_guest_init), but not launched state (sev_launch_start) when performing receive. Once the target has received, it will be in a launched state and will not need to perform the typical SEV launch commands. Signed-off-by: Peter Gonda Suggested-by: Sean Christopherson Reviewed-by: Marc Orr 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 --- Documentation/virt/kvm/api.rst | 15 +++++ arch/x86/include/asm/kvm_host.h | 1 + arch/x86/kvm/svm/sev.c | 101 ++++++++++++++++++++++++++++++++ arch/x86/kvm/svm/svm.c | 1 + arch/x86/kvm/svm/svm.h | 2 + arch/x86/kvm/x86.c | 5 ++ include/uapi/linux/kvm.h | 1 + 7 files changed, 126 insertions(+) diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst index 4ea1bb28297b..e8cecc024649 100644 --- a/Documentation/virt/kvm/api.rst +++ b/Documentation/virt/kvm/api.rst @@ -6702,6 +6702,21 @@ MAP_SHARED mmap will result in an -EINVAL return. When enabled the VMM may make use of the ``KVM_ARM_MTE_COPY_TAGS`` ioctl to perform a bulk copy of tags to/from the guest. +7.29 KVM_CAP_VM_MIGRATE_ENC_CONTEXT_FROM +------------------------------------- + +Architectures: x86 SEV enabled +Type: vm +Parameters: args[0] is the fd of the source vm +Returns: 0 on success + +This capability enables userspace to migrate the encryption context from the vm +indicated by the fd to the vm this is called on. + +This is intended to support intra-host migration of VMs between userspace VMMs. +in-guest workloads scheduled by the host. This allows for upgrading the VMM +process without interrupting the guest. + 8. Other capabilities. ====================== diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 09b256db394a..f06d87a85654 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -1456,6 +1456,7 @@ struct kvm_x86_ops { int (*mem_enc_reg_region)(struct kvm *kvm, struct kvm_enc_region *argp); int (*mem_enc_unreg_region)(struct kvm *kvm, struct kvm_enc_region *argp); int (*vm_copy_enc_context_from)(struct kvm *kvm, unsigned int source_fd); + int (*vm_migrate_enc_context_from)(struct kvm *kvm, unsigned int source_fd); int (*get_msr_feature)(struct kvm_msr_entry *entry); diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c index 46eb1ba62d3d..8db666a362d4 100644 --- a/arch/x86/kvm/svm/sev.c +++ b/arch/x86/kvm/svm/sev.c @@ -1501,6 +1501,107 @@ static int sev_receive_finish(struct kvm *kvm, struct kvm_sev_cmd *argp) return sev_issue_cmd(kvm, SEV_CMD_RECEIVE_FINISH, &data, &argp->error); } +static int svm_sev_lock_for_migration(struct kvm *kvm) +{ + struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info; + + /* + * Bail if this VM is already involved in a migration to avoid deadlock + * between two VMs trying to migrate to/from each other. + */ + if (atomic_cmpxchg_acquire(&sev->migration_in_progress, 0, 1)) + return -EBUSY; + + mutex_lock(&kvm->lock); + + return 0; +} + +static void svm_unlock_after_migration(struct kvm *kvm) +{ + struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info; + + mutex_unlock(&kvm->lock); + atomic_set_release(&sev->migration_in_progress, 0); +} + +static void migrate_info_from(struct kvm_sev_info *dst, + struct kvm_sev_info *src) +{ + sev_asid_free(dst); + + dst->asid = src->asid; + dst->misc_cg = src->misc_cg; + dst->handle = src->handle; + dst->pages_locked = src->pages_locked; + + src->asid = 0; + src->active = false; + src->handle = 0; + src->pages_locked = 0; + src->misc_cg = NULL; + + INIT_LIST_HEAD(&dst->regions_list); + list_replace_init(&src->regions_list, &dst->regions_list); +} + +int svm_vm_migrate_from(struct kvm *kvm, unsigned int source_fd) +{ + struct kvm_sev_info *dst_sev = &to_kvm_svm(kvm)->sev_info; + struct file *source_kvm_file; + struct kvm *source_kvm; + int ret; + + ret = svm_sev_lock_for_migration(kvm); + if (ret) + return ret; + + if (!sev_guest(kvm) || sev_es_guest(kvm)) { + ret = -EINVAL; + pr_warn_ratelimited("VM must be SEV enabled to migrate to.\n"); + goto out_unlock; + } + + if (!list_empty(&dst_sev->regions_list)) { + ret = -EINVAL; + pr_warn_ratelimited( + "VM must not have encrypted regions to migrate to.\n"); + goto out_unlock; + } + + source_kvm_file = fget(source_fd); + if (!file_is_kvm(source_kvm_file)) { + ret = -EBADF; + pr_warn_ratelimited( + "Source VM must be SEV enabled to migrate from.\n"); + goto out_fput; + } + + source_kvm = source_kvm_file->private_data; + ret = svm_sev_lock_for_migration(source_kvm); + if (ret) + goto out_fput; + + if (!sev_guest(source_kvm) || sev_es_guest(source_kvm)) { + ret = -EINVAL; + pr_warn_ratelimited( + "Source VM must be SEV enabled to migrate from.\n"); + goto out_source; + } + + migrate_info_from(dst_sev, &to_kvm_svm(source_kvm)->sev_info); + ret = 0; + +out_source: + svm_unlock_after_migration(source_kvm); +out_fput: + if (source_kvm_file) + fput(source_kvm_file); +out_unlock: + svm_unlock_after_migration(kvm); + return ret; +} + int svm_mem_enc_op(struct kvm *kvm, void __user *argp) { struct kvm_sev_cmd sev_cmd; diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index 1a70e11f0487..88dd76dd966f 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -4625,6 +4625,7 @@ static struct kvm_x86_ops svm_x86_ops __initdata = { .mem_enc_unreg_region = svm_unregister_enc_region, .vm_copy_enc_context_from = svm_vm_copy_asid_from, + .vm_migrate_enc_context_from = svm_vm_migrate_from, .can_emulate_instruction = svm_can_emulate_instruction, diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h index 524d943f3efc..67bfb43301e1 100644 --- a/arch/x86/kvm/svm/svm.h +++ b/arch/x86/kvm/svm/svm.h @@ -80,6 +80,7 @@ struct kvm_sev_info { u64 ap_jump_table; /* SEV-ES AP Jump Table address */ struct kvm *enc_context_owner; /* Owner of copied encryption context */ struct misc_cg *misc_cg; /* For misc cgroup accounting */ + atomic_t migration_in_progress; }; struct kvm_svm { @@ -552,6 +553,7 @@ int svm_register_enc_region(struct kvm *kvm, int svm_unregister_enc_region(struct kvm *kvm, struct kvm_enc_region *range); int svm_vm_copy_asid_from(struct kvm *kvm, unsigned int source_fd); +int svm_vm_migrate_from(struct kvm *kvm, unsigned int source_fd); void pre_sev_run(struct vcpu_svm *svm, int cpu); void __init sev_set_cpu_caps(void); void __init sev_hardware_setup(void); diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 86539c1686fa..c461867d37aa 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -5654,6 +5654,11 @@ int kvm_vm_ioctl_enable_cap(struct kvm *kvm, if (kvm_x86_ops.vm_copy_enc_context_from) r = kvm_x86_ops.vm_copy_enc_context_from(kvm, cap->args[0]); return r; + case KVM_CAP_VM_MIGRATE_ENC_CONTEXT_FROM: + r = -EINVAL; + if (kvm_x86_ops.vm_migrate_enc_context_from) + r = kvm_x86_ops.vm_migrate_enc_context_from(kvm, cap->args[0]); + return r; case KVM_CAP_EXIT_HYPERCALL: if (cap->args[0] & ~KVM_EXIT_HYPERCALL_VALID_MASK) { r = -EINVAL; diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index a067410ebea5..49660204cdb9 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -1112,6 +1112,7 @@ struct kvm_ppc_resize_hpt { #define KVM_CAP_BINARY_STATS_FD 203 #define KVM_CAP_EXIT_ON_EMULATION_FAILURE 204 #define KVM_CAP_ARM_MTE 205 +#define KVM_CAP_VM_MIGRATE_ENC_CONTEXT_FROM 206 #ifdef KVM_CAP_IRQ_ROUTING