From patchwork Thu Aug 19 15:49:09 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Peter Gonda X-Patchwork-Id: 12447521 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 8CC4DC432BE for ; Thu, 19 Aug 2021 15:49:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 73F64610D2 for ; Thu, 19 Aug 2021 15:49:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240678AbhHSPty (ORCPT ); Thu, 19 Aug 2021 11:49:54 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34402 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240595AbhHSPtx (ORCPT ); Thu, 19 Aug 2021 11:49:53 -0400 Received: from mail-qk1-x749.google.com (mail-qk1-x749.google.com [IPv6:2607:f8b0:4864:20::749]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F0DF6C061756 for ; Thu, 19 Aug 2021 08:49:16 -0700 (PDT) Received: by mail-qk1-x749.google.com with SMTP id b9-20020a05620a1269b02903b8bd5c7d95so4440728qkl.12 for ; Thu, 19 Aug 2021 08:49:16 -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=kpAi5BpE2UqrqVFc2FVQVEyUeMMUS53OiFFU2vOoqEk=; b=VdqwCyP4SJqHiSiijdbTjo7svJT0EFHCLAADJXEthSGpVIWXQ/LUfU6ss47Ebrw4P2 HkfrM1gL4kaoDpobcha8INt2qf4xwiSoPEfCIdti3fqmh2qqpdxJrI5eDvL9RrOyNQFQ y+DkPz1I3Mcz5wK2uymIHbvKerhDtEPr9LB14VgIcm4o9PnAPD+Ci+XIHG9NxO7g7XYh 67dtEDuc9lqzs6az8qJrMORQmPfwmnm535x9xiLiEyKUJlUDpCNklcftPHSUcMyXU7vT pOfphDOnDwwGsqjzdtNhkiCRKLNDH5ATg59d4GAXK3ERz3g42L9gNwbzAyc7ajx40gUB GpJg== 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=kpAi5BpE2UqrqVFc2FVQVEyUeMMUS53OiFFU2vOoqEk=; b=T2H4QjdWf9dPcAeHbxASWyTS5rnLP68dOwcGbofAnw7bkcgpQYUHMf2q3B4BL71Q5E HjndPJTEb3cnTpDnNZnJLOJanQASJBMowJeVHyerMgBIJ8nT9YRXY75BDiES2SqTSbEg 9v3IteRKZZDlRMq4cqWRjUuz1M26EYe7/6fs2c6gAtBj8+uTVRpJnSpukoi2lw8HEwBH d5QP+dj/PV/vvoHBQu5cUnP9DxAJ5YCDOh1ASJXisJ7qQwO/4lVVMlZiLDw2+ntrCDDa e0fSacOWG1fyYyVTH71LxgMvgUDcKGYB3KVm+FxepkWHHn8s2NW6Yc2WdX7UjNlN+EI2 Qutg== X-Gm-Message-State: AOAM530iW6ykvE+QVvJ8JFNYvgKW7hm3qg+xXdAdLnnmAvhR4m70LskD L6no2pI1dIuFQOCusLOpeJL3CP9LUJCvuc7NYRWC5hfmdadGFFv6zhVMpf2zuWcrqOKAOB/nR8V 2ioLnfHWjFQu/9ye02HxqF3/nRPIZ8ThTSTESa2pPFpGftDkW/NHfUXrbXg== X-Google-Smtp-Source: ABdhPJzp2mJtjS2j2Pmfg4RyQLs5U25DzJDf1RbZ80hQtP/cyuwXFD0qKOjzGf45hhcUozvGPHdyTniNRjc= X-Received: from pgonda1.kir.corp.google.com ([2620:15c:29:204:6cf4:9d41:7258:8536]) (user=pgonda job=sendgmr) by 2002:a05:6214:324:: with SMTP id j4mr15236233qvu.22.1629388156040; Thu, 19 Aug 2021 08:49:16 -0700 (PDT) Date: Thu, 19 Aug 2021 08:49:09 -0700 In-Reply-To: <20210819154910.1064090-1-pgonda@google.com> Message-Id: <20210819154910.1064090-2-pgonda@google.com> Mime-Version: 1.0 References: <20210819154910.1064090-1-pgonda@google.com> X-Mailer: git-send-email 2.33.0.rc1.237.g0d66db33f3-goog Subject: [PATCH 1/2 V4] 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 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 | 108 ++++++++++++++++++++++++++++++++ arch/x86/kvm/svm/svm.c | 1 + arch/x86/kvm/svm/svm.h | 3 + arch/x86/kvm/x86.c | 5 ++ include/uapi/linux/kvm.h | 1 + 7 files changed, 134 insertions(+) diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst index 86d7ad3a126c..9dc56778b421 100644 --- a/Documentation/virt/kvm/api.rst +++ b/Documentation/virt/kvm/api.rst @@ -6701,6 +6701,21 @@ 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 20daaf67a5bf..fd3a118c9e40 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -1448,6 +1448,7 @@ 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 75e0b21ad07c..2d98b56b6f8c 100644 --- a/arch/x86/kvm/svm/sev.c +++ b/arch/x86/kvm/svm/sev.c @@ -1501,6 +1501,114 @@ 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; + int ret; + + /* + * Bail if this VM is already involved in a migration to avoid deadlock + * between two VMs trying to migrate to/from each other. + */ + spin_lock(&sev->migration_lock); + if (sev->migration_in_progress) + ret = -EBUSY; + else { + /* + * Otherwise indicate VM is migrating and take the KVM lock. + */ + sev->migration_in_progress = true; + mutex_lock(&kvm->lock); + ret = 0; + } + spin_unlock(&sev->migration_lock); + + return ret; +} + +static void svm_unlock_after_migration(struct kvm *kvm) +{ + struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info; + + mutex_unlock(&kvm->lock); + WRITE_ONCE(sev->migration_in_progress, false); +} + +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; + 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 7b58e445a967..8b5bcab48937 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -4627,6 +4627,7 @@ 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..3576a12700d7 100644 --- a/arch/x86/kvm/svm/svm.h +++ b/arch/x86/kvm/svm/svm.h @@ -80,6 +80,8 @@ 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 */ + spinlock_t migration_lock; + bool migration_in_progress; }; struct kvm_svm { @@ -552,6 +554,7 @@ 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 fdc0c18339fb..ea3100134e35 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -5655,6 +5655,11 @@ 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