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=-15.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_2 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 46A81C433E0 for ; Wed, 3 Feb 2021 16:17:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F3CCA64E42 for ; Wed, 3 Feb 2021 16:17:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234700AbhBCQRR (ORCPT ); Wed, 3 Feb 2021 11:17:17 -0500 Received: from 8.mo51.mail-out.ovh.net ([46.105.45.231]:51479 "EHLO 8.mo51.mail-out.ovh.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235011AbhBCQQo (ORCPT ); Wed, 3 Feb 2021 11:16:44 -0500 Received: from mxplan5.mail.ovh.net (unknown [10.108.4.141]) by mo51.mail-out.ovh.net (Postfix) with ESMTPS id 8B62A261D4A; Wed, 3 Feb 2021 17:15:58 +0100 (CET) Received: from kaod.org (37.59.142.104) by DAG8EX1.mxp5.local (172.16.2.71) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2106.2; Wed, 3 Feb 2021 17:15:54 +0100 Authentication-Results: garm.ovh; auth=pass (GARM-104R005d03d0090-901e-436c-a398-7faaa0e21e1c, 14764A637080470E006017DF0F40374BD57DCD59) smtp.auth=groug@kaod.org X-OVh-ClientIp: 78.197.208.248 Date: Wed, 3 Feb 2021 17:15:48 +0100 From: Greg Kurz To: David Gibson CC: , , , , , , , , David Hildenbrand , , , "Marcel Apfelbaum" , , , , Cornelia Huck , , , , , , , , Eduardo Habkost Subject: Re: [PATCH v8 07/13] confidential guest support: Introduce cgs "ready" flag Message-ID: <20210203171548.0d8e0494@bahia.lan> In-Reply-To: <20210202041315.196530-8-david@gibson.dropbear.id.au> References: <20210202041315.196530-1-david@gibson.dropbear.id.au> <20210202041315.196530-8-david@gibson.dropbear.id.au> X-Mailer: Claws Mail 3.17.8 (GTK+ 2.24.32; x86_64-redhat-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Originating-IP: [37.59.142.104] X-ClientProxiedBy: DAG8EX2.mxp5.local (172.16.2.72) To DAG8EX1.mxp5.local (172.16.2.71) X-Ovh-Tracer-GUID: af5f4bdd-8cd5-43de-941a-fb2932b2f48a X-Ovh-Tracer-Id: 14717200635796625759 X-VR-SPAMSTATE: OK X-VR-SPAMSCORE: -100 X-VR-SPAMCAUSE: gggruggvucftvghtrhhoucdtuddrgeduledrgedvgdekgecutefuodetggdotefrodftvfcurfhrohhfihhlvgemucfqggfjpdevjffgvefmvefgnecuuegrihhlohhuthemucehtddtnecusecvtfgvtghiphhivghnthhsucdlqddutddtmdenucfjughrpeffhffvuffkjghfofggtgfgihesthejredtredtvdenucfhrhhomhepifhrvghgucfmuhhriicuoehgrhhouhhgsehkrghougdrohhrgheqnecuggftrfgrthhtvghrnhepfedutdeijeejveehkeeileetgfelteekteehtedtieefffevhffflefftdefleejnecukfhppedtrddtrddtrddtpdefjedrheelrddugedvrddutdegnecuvehluhhsthgvrhfuihiivgeptdenucfrrghrrghmpehmohguvgepshhmthhpqdhouhhtpdhhvghlohepmhigphhlrghnhedrmhgrihhlrdhovhhhrdhnvghtpdhinhgvtheptddrtddrtddrtddpmhgrihhlfhhrohhmpehgrhhouhhgsehkrghougdrohhrghdprhgtphhtthhopegvhhgrsghkohhsthesrhgvughhrghtrdgtohhm Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Tue, 2 Feb 2021 15:13:09 +1100 David Gibson wrote: > The platform specific details of mechanisms for implementing > confidential guest support may require setup at various points during > initialization. Thus, it's not really feasible to have a single cgs > initialization hook, but instead each mechanism needs its own > initialization calls in arch or machine specific code. > > However, to make it harder to have a bug where a mechanism isn't > properly initialized under some circumstances, we want to have a > common place, late in boot, where we verify that cgs has been > initialized if it was requested. > > This patch introduces a ready flag to the ConfidentialGuestSupport > base type to accomplish this, which we verify in > qemu_machine_creation_done(). > > Signed-off-by: David Gibson > --- > include/exec/confidential-guest-support.h | 24 +++++++++++++++++++++++ > softmmu/vl.c | 10 ++++++++++ > target/i386/sev.c | 2 ++ > 3 files changed, 36 insertions(+) > > diff --git a/include/exec/confidential-guest-support.h b/include/exec/confidential-guest-support.h > index 3db6380e63..5dcf602047 100644 > --- a/include/exec/confidential-guest-support.h > +++ b/include/exec/confidential-guest-support.h > @@ -27,6 +27,30 @@ OBJECT_DECLARE_SIMPLE_TYPE(ConfidentialGuestSupport, CONFIDENTIAL_GUEST_SUPPORT) > > struct ConfidentialGuestSupport { > Object parent; > + > + /* > + * ready: flag set by CGS initialization code once it's ready to > + * start executing instructions in a potentially-secure > + * guest > + * > + * The definition here is a bit fuzzy, because this is essentially > + * part of a self-sanity-check, rather than a strict mechanism. > + * > + * It's not fasible to have a single point in the common machine s/fasible/feasible Anyway, Reviewed-by: Greg Kurz > + * init path to configure confidential guest support, because > + * different mechanisms have different interdependencies requiring > + * initialization in different places, often in arch or machine > + * type specific code. It's also usually not possible to check > + * for invalid configurations until that initialization code. > + * That means it would be very easy to have a bug allowing CGS > + * init to be bypassed entirely in certain configurations. > + * > + * Silently ignoring a requested security feature would be bad, so > + * to avoid that we check late in init that this 'ready' flag is > + * set if CGS was requested. If the CGS init hasn't happened, and > + * so 'ready' is not set, we'll abort. > + */ > + bool ready; > }; > > typedef struct ConfidentialGuestSupportClass { > diff --git a/softmmu/vl.c b/softmmu/vl.c > index 1b464e3474..1869ed54a9 100644 > --- a/softmmu/vl.c > +++ b/softmmu/vl.c > @@ -101,6 +101,7 @@ > #include "qemu/plugin.h" > #include "qemu/queue.h" > #include "sysemu/arch_init.h" > +#include "exec/confidential-guest-support.h" > > #include "ui/qemu-spice.h" > #include "qapi/string-input-visitor.h" > @@ -2497,6 +2498,8 @@ static void qemu_create_cli_devices(void) > > static void qemu_machine_creation_done(void) > { > + MachineState *machine = MACHINE(qdev_get_machine()); > + > /* Did we create any drives that we failed to create a device for? */ > drive_check_orphaned(); > > @@ -2516,6 +2519,13 @@ static void qemu_machine_creation_done(void) > > qdev_machine_creation_done(); > > + if (machine->cgs) { > + /* > + * Verify that Confidential Guest Support has actually been initialized > + */ > + assert(machine->cgs->ready); > + } > + > if (foreach_device_config(DEV_GDB, gdbserver_start) < 0) { > exit(1); > } > diff --git a/target/i386/sev.c b/target/i386/sev.c > index 590cb31fa8..f9e9b5d8ae 100644 > --- a/target/i386/sev.c > +++ b/target/i386/sev.c > @@ -737,6 +737,8 @@ int sev_kvm_init(ConfidentialGuestSupport *cgs, Error **errp) > qemu_add_machine_init_done_notifier(&sev_machine_done_notify); > qemu_add_vm_change_state_handler(sev_vm_state_change, sev); > > + cgs->ready = true; > + > return 0; > err: > sev_guest = NULL; 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=-15.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_2 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 27CF1C433E6 for ; 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Wed, 03 Feb 2021 11:16:17 -0500 Received: from mxplan5.mail.ovh.net (unknown [10.108.4.141]) by mo51.mail-out.ovh.net (Postfix) with ESMTPS id 8B62A261D4A; Wed, 3 Feb 2021 17:15:58 +0100 (CET) Received: from kaod.org (37.59.142.104) by DAG8EX1.mxp5.local (172.16.2.71) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2106.2; Wed, 3 Feb 2021 17:15:54 +0100 Authentication-Results: garm.ovh; auth=pass (GARM-104R005d03d0090-901e-436c-a398-7faaa0e21e1c, 14764A637080470E006017DF0F40374BD57DCD59) smtp.auth=groug@kaod.org X-OVh-ClientIp: 78.197.208.248 Date: Wed, 3 Feb 2021 17:15:48 +0100 From: Greg Kurz To: David Gibson Subject: Re: [PATCH v8 07/13] confidential guest support: Introduce cgs "ready" flag Message-ID: <20210203171548.0d8e0494@bahia.lan> In-Reply-To: <20210202041315.196530-8-david@gibson.dropbear.id.au> References: <20210202041315.196530-1-david@gibson.dropbear.id.au> <20210202041315.196530-8-david@gibson.dropbear.id.au> X-Mailer: Claws Mail 3.17.8 (GTK+ 2.24.32; x86_64-redhat-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Originating-IP: [37.59.142.104] X-ClientProxiedBy: DAG8EX2.mxp5.local (172.16.2.72) To DAG8EX1.mxp5.local (172.16.2.71) X-Ovh-Tracer-GUID: af5f4bdd-8cd5-43de-941a-fb2932b2f48a X-Ovh-Tracer-Id: 14717200635796625759 X-VR-SPAMSTATE: OK X-VR-SPAMSCORE: -100 X-VR-SPAMCAUSE: gggruggvucftvghtrhhoucdtuddrgeduledrgedvgdekgecutefuodetggdotefrodftvfcurfhrohhfihhlvgemucfqggfjpdevjffgvefmvefgnecuuegrihhlohhuthemucehtddtnecusecvtfgvtghiphhivghnthhsucdlqddutddtmdenucfjughrpeffhffvuffkjghfofggtgfgihesthejredtredtvdenucfhrhhomhepifhrvghgucfmuhhriicuoehgrhhouhhgsehkrghougdrohhrgheqnecuggftrfgrthhtvghrnhepfedutdeijeejveehkeeileetgfelteekteehtedtieefffevhffflefftdefleejnecukfhppedtrddtrddtrddtpdefjedrheelrddugedvrddutdegnecuvehluhhsthgvrhfuihiivgeptdenucfrrghrrghmpehmohguvgepshhmthhpqdhouhhtpdhhvghlohepmhigphhlrghnhedrmhgrihhlrdhovhhhrdhnvghtpdhinhgvtheptddrtddrtddrtddpmhgrihhlfhhrohhmpehgrhhouhhgsehkrghougdrohhrghdprhgtphhtthhopegvhhgrsghkohhsthesrhgvughhrghtrdgtohhm Received-SPF: pass client-ip=188.165.32.156; envelope-from=groug@kaod.org; helo=3.mo51.mail-out.ovh.net X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H2=-0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=unavailable autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: pair@us.ibm.com, mtosatti@redhat.com, brijesh.singh@amd.com, kvm@vger.kernel.org, David Hildenbrand , qemu-devel@nongnu.org, frankja@linux.ibm.com, borntraeger@de.ibm.com, mst@redhat.com, mdroth@linux.vnet.ibm.com, pasic@linux.ibm.com, pragyansri.pathi@intel.com, andi.kleen@intel.com, thuth@redhat.com, Eduardo Habkost , richard.henderson@linaro.org, dgilbert@redhat.com, qemu-s390x@nongnu.org, jun.nakajima@intel.com, berrange@redhat.com, Cornelia Huck , qemu-ppc@nongnu.org, pbonzini@redhat.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Tue, 2 Feb 2021 15:13:09 +1100 David Gibson wrote: > The platform specific details of mechanisms for implementing > confidential guest support may require setup at various points during > initialization. Thus, it's not really feasible to have a single cgs > initialization hook, but instead each mechanism needs its own > initialization calls in arch or machine specific code. > > However, to make it harder to have a bug where a mechanism isn't > properly initialized under some circumstances, we want to have a > common place, late in boot, where we verify that cgs has been > initialized if it was requested. > > This patch introduces a ready flag to the ConfidentialGuestSupport > base type to accomplish this, which we verify in > qemu_machine_creation_done(). > > Signed-off-by: David Gibson > --- > include/exec/confidential-guest-support.h | 24 +++++++++++++++++++++++ > softmmu/vl.c | 10 ++++++++++ > target/i386/sev.c | 2 ++ > 3 files changed, 36 insertions(+) > > diff --git a/include/exec/confidential-guest-support.h b/include/exec/confidential-guest-support.h > index 3db6380e63..5dcf602047 100644 > --- a/include/exec/confidential-guest-support.h > +++ b/include/exec/confidential-guest-support.h > @@ -27,6 +27,30 @@ OBJECT_DECLARE_SIMPLE_TYPE(ConfidentialGuestSupport, CONFIDENTIAL_GUEST_SUPPORT) > > struct ConfidentialGuestSupport { > Object parent; > + > + /* > + * ready: flag set by CGS initialization code once it's ready to > + * start executing instructions in a potentially-secure > + * guest > + * > + * The definition here is a bit fuzzy, because this is essentially > + * part of a self-sanity-check, rather than a strict mechanism. > + * > + * It's not fasible to have a single point in the common machine s/fasible/feasible Anyway, Reviewed-by: Greg Kurz > + * init path to configure confidential guest support, because > + * different mechanisms have different interdependencies requiring > + * initialization in different places, often in arch or machine > + * type specific code. It's also usually not possible to check > + * for invalid configurations until that initialization code. > + * That means it would be very easy to have a bug allowing CGS > + * init to be bypassed entirely in certain configurations. > + * > + * Silently ignoring a requested security feature would be bad, so > + * to avoid that we check late in init that this 'ready' flag is > + * set if CGS was requested. If the CGS init hasn't happened, and > + * so 'ready' is not set, we'll abort. > + */ > + bool ready; > }; > > typedef struct ConfidentialGuestSupportClass { > diff --git a/softmmu/vl.c b/softmmu/vl.c > index 1b464e3474..1869ed54a9 100644 > --- a/softmmu/vl.c > +++ b/softmmu/vl.c > @@ -101,6 +101,7 @@ > #include "qemu/plugin.h" > #include "qemu/queue.h" > #include "sysemu/arch_init.h" > +#include "exec/confidential-guest-support.h" > > #include "ui/qemu-spice.h" > #include "qapi/string-input-visitor.h" > @@ -2497,6 +2498,8 @@ static void qemu_create_cli_devices(void) > > static void qemu_machine_creation_done(void) > { > + MachineState *machine = MACHINE(qdev_get_machine()); > + > /* Did we create any drives that we failed to create a device for? */ > drive_check_orphaned(); > > @@ -2516,6 +2519,13 @@ static void qemu_machine_creation_done(void) > > qdev_machine_creation_done(); > > + if (machine->cgs) { > + /* > + * Verify that Confidential Guest Support has actually been initialized > + */ > + assert(machine->cgs->ready); > + } > + > if (foreach_device_config(DEV_GDB, gdbserver_start) < 0) { > exit(1); > } > diff --git a/target/i386/sev.c b/target/i386/sev.c > index 590cb31fa8..f9e9b5d8ae 100644 > --- a/target/i386/sev.c > +++ b/target/i386/sev.c > @@ -737,6 +737,8 @@ int sev_kvm_init(ConfidentialGuestSupport *cgs, Error **errp) > qemu_add_machine_init_done_notifier(&sev_machine_done_notify); > qemu_add_vm_change_state_handler(sev_vm_state_change, sev); > > + cgs->ready = true; > + > return 0; > err: > sev_guest = NULL;