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 Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 93395C04FFE for ; Tue, 23 Apr 2024 15:20:39 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1rzHnT-0006Hb-VA; Tue, 23 Apr 2024 11:11:04 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1rzHnC-0004k8-Ik for qemu-devel@nongnu.org; Tue, 23 Apr 2024 11:10:46 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1rzHn7-0000HG-TN for qemu-devel@nongnu.org; Tue, 23 Apr 2024 11:10:44 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1713885036; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=Pk99K/zTrVRxPz+P8bURNxdcIAFJCpNOuMmTg+GIdgo=; b=dyN9ZqINAUfPQS6DUj6IyuzxWODhlCdipKIM45rQm1ZosgM100pRKCYYoaB3FM4enx7qNw SpsFKFuiAs2jP12vmSGLuhBNWj3sFOfyES6l3bWqvB3Rs/appN/EKobOQvJIeJnzpuP7vg Xu0bongCXOHrV9bMS4kqNkRsDq7eaQo= Received: from mimecast-mx02.redhat.com (mx-ext.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-446-S0GDEyXgO_S0i4n7xsOe1Q-1; Tue, 23 Apr 2024 11:10:34 -0400 X-MC-Unique: S0GDEyXgO_S0i4n7xsOe1Q-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.rdu2.redhat.com [10.11.54.4]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 1551829AC013; Tue, 23 Apr 2024 15:10:34 +0000 (UTC) Received: from avogadro.lan (unknown [10.39.192.70]) by smtp.corp.redhat.com (Postfix) with ESMTP id 80C6820128F3; Tue, 23 Apr 2024 15:10:33 +0000 (UTC) From: Paolo Bonzini To: qemu-devel@nongnu.org Cc: =?UTF-8?q?Philippe=20Mathieu-Daud=C3=A9?= Subject: [PULL 40/63] KVM: track whether guest state is encrypted Date: Tue, 23 Apr 2024 17:09:28 +0200 Message-ID: <20240423150951.41600-41-pbonzini@redhat.com> In-Reply-To: <20240423150951.41600-1-pbonzini@redhat.com> References: <20240423150951.41600-1-pbonzini@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.4 Received-SPF: pass client-ip=170.10.133.124; envelope-from=pbonzini@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -27 X-Spam_score: -2.8 X-Spam_bar: -- X-Spam_report: (-2.8 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.67, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org So far, KVM has allowed KVM_GET/SET_* ioctls to execute even if the guest state is encrypted, in which case they do nothing. For the new API using VM types, instead, the ioctls will fail which is a safer and more robust approach. The new API will be the only one available for SEV-SNP and TDX, but it is also usable for SEV and SEV-ES. In preparation for that, require architecture-specific KVM code to communicate the point at which guest state is protected (which must be after kvm_cpu_synchronize_post_init(), though that might change in the future in order to suppor migration). >From that point, skip reading registers so that cpu->vcpu_dirty is never true: if it ever becomes true, kvm_arch_put_registers() will fail miserably. Reviewed-by: Philippe Mathieu-Daudé Signed-off-by: Paolo Bonzini --- include/sysemu/kvm.h | 2 ++ include/sysemu/kvm_int.h | 1 + accel/kvm/kvm-all.c | 17 ++++++++++++++--- target/i386/sev.c | 1 + 4 files changed, 18 insertions(+), 3 deletions(-) diff --git a/include/sysemu/kvm.h b/include/sysemu/kvm.h index 2cba899270c..14b1ddb3be1 100644 --- a/include/sysemu/kvm.h +++ b/include/sysemu/kvm.h @@ -539,6 +539,8 @@ bool kvm_dirty_ring_enabled(void); uint32_t kvm_dirty_ring_size(void); +void kvm_mark_guest_state_protected(void); + /** * kvm_hwpoisoned_mem - indicate if there is any hwpoisoned page * reported for the VM. diff --git a/include/sysemu/kvm_int.h b/include/sysemu/kvm_int.h index 94488d2c1a2..227b61fec3d 100644 --- a/include/sysemu/kvm_int.h +++ b/include/sysemu/kvm_int.h @@ -87,6 +87,7 @@ struct KVMState bool kernel_irqchip_required; OnOffAuto kernel_irqchip_split; bool sync_mmu; + bool guest_state_protected; uint64_t manual_dirty_log_protect; /* The man page (and posix) say ioctl numbers are signed int, but * they're not. Linux, glibc and *BSD all treat ioctl numbers as diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c index d58916e33ae..d6ebadbf386 100644 --- a/accel/kvm/kvm-all.c +++ b/accel/kvm/kvm-all.c @@ -2703,7 +2703,7 @@ bool kvm_cpu_check_are_resettable(void) static void do_kvm_cpu_synchronize_state(CPUState *cpu, run_on_cpu_data arg) { - if (!cpu->vcpu_dirty) { + if (!cpu->vcpu_dirty && !kvm_state->guest_state_protected) { int ret = kvm_arch_get_registers(cpu); if (ret) { error_report("Failed to get registers: %s", strerror(-ret)); @@ -2717,7 +2717,7 @@ static void do_kvm_cpu_synchronize_state(CPUState *cpu, run_on_cpu_data arg) void kvm_cpu_synchronize_state(CPUState *cpu) { - if (!cpu->vcpu_dirty) { + if (!cpu->vcpu_dirty && !kvm_state->guest_state_protected) { run_on_cpu(cpu, do_kvm_cpu_synchronize_state, RUN_ON_CPU_NULL); } } @@ -2752,7 +2752,13 @@ static void do_kvm_cpu_synchronize_post_init(CPUState *cpu, run_on_cpu_data arg) void kvm_cpu_synchronize_post_init(CPUState *cpu) { - run_on_cpu(cpu, do_kvm_cpu_synchronize_post_init, RUN_ON_CPU_NULL); + if (!kvm_state->guest_state_protected) { + /* + * This runs before the machine_init_done notifiers, and is the last + * opportunity to synchronize the state of confidential guests. + */ + run_on_cpu(cpu, do_kvm_cpu_synchronize_post_init, RUN_ON_CPU_NULL); + } } static void do_kvm_cpu_synchronize_pre_loadvm(CPUState *cpu, run_on_cpu_data arg) @@ -4099,3 +4105,8 @@ void query_stats_schemas_cb(StatsSchemaList **result, Error **errp) query_stats_schema_vcpu(first_cpu, &stats_args); } } + +void kvm_mark_guest_state_protected(void) +{ + kvm_state->guest_state_protected = true; +} diff --git a/target/i386/sev.c b/target/i386/sev.c index b8f79d34d19..c49a8fd55eb 100644 --- a/target/i386/sev.c +++ b/target/i386/sev.c @@ -755,6 +755,7 @@ sev_launch_get_measure(Notifier *notifier, void *unused) if (ret) { exit(1); } + kvm_mark_guest_state_protected(); } /* query the measurement blob length */ -- 2.44.0