From patchwork Tue Feb 6 19:06:06 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Hajnoczi X-Patchwork-Id: 13547742 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 44427C48297 for ; Tue, 6 Feb 2024 19:07:17 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1rXQm1-0008IC-Ag; Tue, 06 Feb 2024 14:06:25 -0500 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 1rXQm0-0008Ha-C7 for qemu-devel@nongnu.org; Tue, 06 Feb 2024 14:06:24 -0500 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 1rXQly-0000eO-G2 for qemu-devel@nongnu.org; Tue, 06 Feb 2024 14:06:24 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1707246381; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=zd00/eSHCWjYaWUzdyc1RU+DgeFJvNq6u2T6kNcIzaU=; b=caEFnYDlD8JGaE7OFbtCKnkP0EvkrE09j/DBFHv8xWuPUqxtASfFqM0kT+2RO7+L3bjJ8L ybrR6wmEfvM0BWNQBuOYs6PjxP69NFOAn+Mbsd/hgUKvubQ7u8b4DXHRDXiNajvRKSnI8J dKil513aIXPE0HyfLff9N6rgtRfEj88= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-624-9-9AqYy2N4C1knD7epWozw-1; Tue, 06 Feb 2024 14:06:16 -0500 X-MC-Unique: 9-9AqYy2N4C1knD7epWozw-1 Received: from smtp.corp.redhat.com (int-mx09.intmail.prod.int.rdu2.redhat.com [10.11.54.9]) (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 03D2E8489EF; Tue, 6 Feb 2024 19:06:15 +0000 (UTC) Received: from localhost (unknown [10.39.192.41]) by smtp.corp.redhat.com (Postfix) with ESMTP id 5DAD5492BC7; Tue, 6 Feb 2024 19:06:14 +0000 (UTC) From: Stefan Hajnoczi To: qemu-devel@nongnu.org Cc: Stefan Hajnoczi , Michael Roth , Kevin Wolf , "Michael S. Tsirkin" , Markus Armbruster , Hanna Reitz , qemu-block@nongnu.org, Manos Pitsidianakis Subject: [PATCH v2 1/5] virtio-blk: enforce iothread-vq-mapping validation Date: Tue, 6 Feb 2024 14:06:06 -0500 Message-ID: <20240206190610.107963-2-stefanha@redhat.com> In-Reply-To: <20240206190610.107963-1-stefanha@redhat.com> References: <20240206190610.107963-1-stefanha@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.9 Received-SPF: pass client-ip=170.10.133.124; envelope-from=stefanha@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -23 X-Spam_score: -2.4 X-Spam_bar: -- X-Spam_report: (-2.4 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.294, 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_H5=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=unavailable 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 Hanna Czenczek noticed that the safety of `vq_aio_context[vq->value] = ctx;` with user-defined vq->value inputs is not obvious. The code is structured in validate() + apply() steps so input validation is there, but it happens way earlier and there is nothing that guarantees apply() can only be called with validated inputs. This patch moves the validate() call inside the apply() function so validation is guaranteed. I also added the bounds checking assertion that Hanna suggested. Signed-off-by: Stefan Hajnoczi Reviewed-by: Manos Pitsidianakis Reviewed-by: Hanna Czenczek --- hw/block/virtio-blk.c | 191 +++++++++++++++++++++++------------------- 1 file changed, 106 insertions(+), 85 deletions(-) diff --git a/hw/block/virtio-blk.c b/hw/block/virtio-blk.c index 227d83569f..6e3e3a23ee 100644 --- a/hw/block/virtio-blk.c +++ b/hw/block/virtio-blk.c @@ -1485,6 +1485,72 @@ static int virtio_blk_load_device(VirtIODevice *vdev, QEMUFile *f, return 0; } +static void virtio_resize_cb(void *opaque) +{ + VirtIODevice *vdev = opaque; + + assert(qemu_get_current_aio_context() == qemu_get_aio_context()); + virtio_notify_config(vdev); +} + +static void virtio_blk_resize(void *opaque) +{ + VirtIODevice *vdev = VIRTIO_DEVICE(opaque); + + /* + * virtio_notify_config() needs to acquire the BQL, + * so it can't be called from an iothread. Instead, schedule + * it to be run in the main context BH. + */ + aio_bh_schedule_oneshot(qemu_get_aio_context(), virtio_resize_cb, vdev); +} + +static void virtio_blk_ioeventfd_detach(VirtIOBlock *s) +{ + VirtIODevice *vdev = VIRTIO_DEVICE(s); + + for (uint16_t i = 0; i < s->conf.num_queues; i++) { + VirtQueue *vq = virtio_get_queue(vdev, i); + virtio_queue_aio_detach_host_notifier(vq, s->vq_aio_context[i]); + } +} + +static void virtio_blk_ioeventfd_attach(VirtIOBlock *s) +{ + VirtIODevice *vdev = VIRTIO_DEVICE(s); + + for (uint16_t i = 0; i < s->conf.num_queues; i++) { + VirtQueue *vq = virtio_get_queue(vdev, i); + virtio_queue_aio_attach_host_notifier(vq, s->vq_aio_context[i]); + } +} + +/* Suspend virtqueue ioeventfd processing during drain */ +static void virtio_blk_drained_begin(void *opaque) +{ + VirtIOBlock *s = opaque; + + if (s->ioeventfd_started) { + virtio_blk_ioeventfd_detach(s); + } +} + +/* Resume virtqueue ioeventfd processing after drain */ +static void virtio_blk_drained_end(void *opaque) +{ + VirtIOBlock *s = opaque; + + if (s->ioeventfd_started) { + virtio_blk_ioeventfd_attach(s); + } +} + +static const BlockDevOps virtio_block_ops = { + .resize_cb = virtio_blk_resize, + .drained_begin = virtio_blk_drained_begin, + .drained_end = virtio_blk_drained_end, +}; + static bool validate_iothread_vq_mapping_list(IOThreadVirtQueueMappingList *list, uint16_t num_queues, Error **errp) @@ -1547,81 +1613,33 @@ validate_iothread_vq_mapping_list(IOThreadVirtQueueMappingList *list, return true; } -static void virtio_resize_cb(void *opaque) -{ - VirtIODevice *vdev = opaque; - - assert(qemu_get_current_aio_context() == qemu_get_aio_context()); - virtio_notify_config(vdev); -} - -static void virtio_blk_resize(void *opaque) -{ - VirtIODevice *vdev = VIRTIO_DEVICE(opaque); - - /* - * virtio_notify_config() needs to acquire the BQL, - * so it can't be called from an iothread. Instead, schedule - * it to be run in the main context BH. - */ - aio_bh_schedule_oneshot(qemu_get_aio_context(), virtio_resize_cb, vdev); -} - -static void virtio_blk_ioeventfd_detach(VirtIOBlock *s) -{ - VirtIODevice *vdev = VIRTIO_DEVICE(s); - - for (uint16_t i = 0; i < s->conf.num_queues; i++) { - VirtQueue *vq = virtio_get_queue(vdev, i); - virtio_queue_aio_detach_host_notifier(vq, s->vq_aio_context[i]); - } -} - -static void virtio_blk_ioeventfd_attach(VirtIOBlock *s) -{ - VirtIODevice *vdev = VIRTIO_DEVICE(s); - - for (uint16_t i = 0; i < s->conf.num_queues; i++) { - VirtQueue *vq = virtio_get_queue(vdev, i); - virtio_queue_aio_attach_host_notifier(vq, s->vq_aio_context[i]); - } -} - -/* Suspend virtqueue ioeventfd processing during drain */ -static void virtio_blk_drained_begin(void *opaque) -{ - VirtIOBlock *s = opaque; - - if (s->ioeventfd_started) { - virtio_blk_ioeventfd_detach(s); - } -} - -/* Resume virtqueue ioeventfd processing after drain */ -static void virtio_blk_drained_end(void *opaque) -{ - VirtIOBlock *s = opaque; - - if (s->ioeventfd_started) { - virtio_blk_ioeventfd_attach(s); - } -} - -static const BlockDevOps virtio_block_ops = { - .resize_cb = virtio_blk_resize, - .drained_begin = virtio_blk_drained_begin, - .drained_end = virtio_blk_drained_end, -}; - -/* Generate vq:AioContext mappings from a validated iothread-vq-mapping list */ -static void -apply_vq_mapping(IOThreadVirtQueueMappingList *iothread_vq_mapping_list, - AioContext **vq_aio_context, uint16_t num_queues) +/** + * apply_iothread_vq_mapping: + * @iothread_vq_mapping_list: The mapping of virtqueues to IOThreads. + * @vq_aio_context: The array of AioContext pointers to fill in. + * @num_queues: The length of @vq_aio_context. + * @errp: If an error occurs, a pointer to the area to store the error. + * + * Fill in the AioContext for each virtqueue in the @vq_aio_context array given + * the iothread-vq-mapping parameter in @iothread_vq_mapping_list. + * + * Returns: %true on success, %false on failure. + **/ +static bool apply_iothread_vq_mapping( + IOThreadVirtQueueMappingList *iothread_vq_mapping_list, + AioContext **vq_aio_context, + uint16_t num_queues, + Error **errp) { IOThreadVirtQueueMappingList *node; size_t num_iothreads = 0; size_t cur_iothread = 0; + if (!validate_iothread_vq_mapping_list(iothread_vq_mapping_list, + num_queues, errp)) { + return false; + } + for (node = iothread_vq_mapping_list; node; node = node->next) { num_iothreads++; } @@ -1638,6 +1656,7 @@ apply_vq_mapping(IOThreadVirtQueueMappingList *iothread_vq_mapping_list, /* Explicit vq:IOThread assignment */ for (vq = node->value->vqs; vq; vq = vq->next) { + assert(vq->value < num_queues); vq_aio_context[vq->value] = ctx; } } else { @@ -1650,6 +1669,8 @@ apply_vq_mapping(IOThreadVirtQueueMappingList *iothread_vq_mapping_list, cur_iothread++; } + + return true; } /* Context: BQL held */ @@ -1660,6 +1681,13 @@ static bool virtio_blk_vq_aio_context_init(VirtIOBlock *s, Error **errp) BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev))); VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); + if (conf->iothread && conf->iothread_vq_mapping_list) { + error_setg(errp, + "iothread and iothread-vq-mapping properties cannot be set " + "at the same time"); + return false; + } + if (conf->iothread || conf->iothread_vq_mapping_list) { if (!k->set_guest_notifiers || !k->ioeventfd_assign) { error_setg(errp, @@ -1685,8 +1713,14 @@ static bool virtio_blk_vq_aio_context_init(VirtIOBlock *s, Error **errp) s->vq_aio_context = g_new(AioContext *, conf->num_queues); if (conf->iothread_vq_mapping_list) { - apply_vq_mapping(conf->iothread_vq_mapping_list, s->vq_aio_context, - conf->num_queues); + if (!apply_iothread_vq_mapping(conf->iothread_vq_mapping_list, + s->vq_aio_context, + conf->num_queues, + errp)) { + g_free(s->vq_aio_context); + s->vq_aio_context = NULL; + return false; + } } else if (conf->iothread) { AioContext *ctx = iothread_get_aio_context(conf->iothread); for (unsigned i = 0; i < conf->num_queues; i++) { @@ -1996,19 +2030,6 @@ static void virtio_blk_device_realize(DeviceState *dev, Error **errp) return; } - if (conf->iothread_vq_mapping_list) { - if (conf->iothread) { - error_setg(errp, "iothread and iothread-vq-mapping properties " - "cannot be set at the same time"); - return; - } - - if (!validate_iothread_vq_mapping_list(conf->iothread_vq_mapping_list, - conf->num_queues, errp)) { - return; - } - } - s->config_size = virtio_get_config_size(&virtio_blk_cfg_size_params, s->host_features); virtio_init(vdev, VIRTIO_ID_BLOCK, s->config_size); From patchwork Tue Feb 6 19:06:07 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Hajnoczi X-Patchwork-Id: 13547745 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 D96E1C4828D for ; Tue, 6 Feb 2024 19:07:37 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1rXQm5-0008Iw-M7; Tue, 06 Feb 2024 14:06:29 -0500 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 1rXQm4-0008IR-BT for qemu-devel@nongnu.org; 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Tue, 06 Feb 2024 14:06:19 -0500 X-MC-Unique: iUrt1BmMO6alqfTzoSqs2g-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.rdu2.redhat.com [10.11.54.8]) (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 0792038300B9; Tue, 6 Feb 2024 19:06:18 +0000 (UTC) Received: from localhost (unknown [10.39.192.41]) by smtp.corp.redhat.com (Postfix) with ESMTP id 09D4DC07F51; Tue, 6 Feb 2024 19:06:16 +0000 (UTC) From: Stefan Hajnoczi To: qemu-devel@nongnu.org Cc: Stefan Hajnoczi , Michael Roth , Kevin Wolf , "Michael S. Tsirkin" , Markus Armbruster , Hanna Reitz , qemu-block@nongnu.org, Manos Pitsidianakis Subject: [PATCH v2 2/5] virtio-blk: clarify that there is at least 1 virtqueue Date: Tue, 6 Feb 2024 14:06:07 -0500 Message-ID: <20240206190610.107963-3-stefanha@redhat.com> In-Reply-To: <20240206190610.107963-1-stefanha@redhat.com> References: <20240206190610.107963-1-stefanha@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.8 Received-SPF: pass client-ip=170.10.129.124; envelope-from=stefanha@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -23 X-Spam_score: -2.4 X-Spam_bar: -- X-Spam_report: (-2.4 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.294, 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_H2=-0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 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 It is not possible to instantiate a virtio-blk device with 0 virtqueues. The following check is located in ->realize(): if (!conf->num_queues) { error_setg(errp, "num-queues property must be larger than 0"); return; } Later on we access s->vq_aio_context[0] under the assumption that there is as least one virtqueue. Hanna Czenczek noted that it would help to show that the array index is already valid. Add an assertion to document that s->vq_aio_context[0] is always safe...and catch future code changes that break this assumption. Suggested-by: Hanna Czenczek Reviewed-by: Manos Pitsidianakis Reviewed-by: Hanna Czenczek Signed-off-by: Stefan Hajnoczi --- hw/block/virtio-blk.c | 1 + 1 file changed, 1 insertion(+) diff --git a/hw/block/virtio-blk.c b/hw/block/virtio-blk.c index 6e3e3a23ee..e430ba583c 100644 --- a/hw/block/virtio-blk.c +++ b/hw/block/virtio-blk.c @@ -1824,6 +1824,7 @@ static int virtio_blk_start_ioeventfd(VirtIODevice *vdev) * Try to change the AioContext so that block jobs and other operations can * co-locate their activity in the same AioContext. If it fails, nevermind. */ + assert(nvqs > 0); /* enforced during ->realize() */ r = blk_set_aio_context(s->conf.conf.blk, s->vq_aio_context[0], &local_err); if (r < 0) { From patchwork Tue Feb 6 19:06:08 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Hajnoczi X-Patchwork-Id: 13547744 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 C9151C4829D for ; Tue, 6 Feb 2024 19:07:36 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1rXQmJ-0008Nh-J1; Tue, 06 Feb 2024 14:06:43 -0500 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 1rXQmA-0008Ls-Ug for qemu-devel@nongnu.org; Tue, 06 Feb 2024 14:06:35 -0500 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 1rXQm9-0000il-F7 for qemu-devel@nongnu.org; Tue, 06 Feb 2024 14:06:34 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1707246393; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=PNApsZca7sOyl8N6SobE6R14zQv1GO12NmWRtOt+4XQ=; b=SqZK2r9h7iEsYpwbFr++uhYo+F9FVBnUGrOP3F0Q+vRkg60wL3c26FFbs+lw/zEgQBe7aT D+xzcoVdQgp09ObRmze0YGKlNEPVsUJZYPkjfvpaOlvzYmUX59/8ArKqWvg83+ScCGszaE ygb2GHJ8ZgGoYEF5AWaRkWtgEUECH+0= 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-422-4NXMZMuBPZyNBjsOilPzxg-1; Tue, 06 Feb 2024 14:06:27 -0500 X-MC-Unique: 4NXMZMuBPZyNBjsOilPzxg-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (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 6A5223C0F24A; Tue, 6 Feb 2024 19:06:20 +0000 (UTC) Received: from localhost (unknown [10.39.192.41]) by smtp.corp.redhat.com (Postfix) with ESMTP id C5B2C2166B35; Tue, 6 Feb 2024 19:06:19 +0000 (UTC) From: Stefan Hajnoczi To: qemu-devel@nongnu.org Cc: Stefan Hajnoczi , Michael Roth , Kevin Wolf , "Michael S. Tsirkin" , Markus Armbruster , Hanna Reitz , qemu-block@nongnu.org, Manos Pitsidianakis Subject: [PATCH v2 3/5] virtio-blk: add vq_rq[] bounds check in virtio_blk_dma_restart_cb() Date: Tue, 6 Feb 2024 14:06:08 -0500 Message-ID: <20240206190610.107963-4-stefanha@redhat.com> In-Reply-To: <20240206190610.107963-1-stefanha@redhat.com> References: <20240206190610.107963-1-stefanha@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.6 Received-SPF: pass client-ip=170.10.133.124; envelope-from=stefanha@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -23 X-Spam_score: -2.4 X-Spam_bar: -- X-Spam_report: (-2.4 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.294, 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_H5=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=unavailable 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 Hanna Czenczek noted that the array index in virtio_blk_dma_restart_cb() is not bounds-checked: g_autofree VirtIOBlockReq **vq_rq = g_new0(VirtIOBlockReq *, num_queues); ... while (rq) { VirtIOBlockReq *next = rq->next; uint16_t idx = virtio_get_queue_index(rq->vq); rq->next = vq_rq[idx]; ^^^^^^^^^^ The code is correct because both rq->vq and vq_rq[] depend on num_queues, but this is indirect and not 100% obvious. Add an assertion. Suggested-by: Hanna Czenczek Reviewed-by: Manos Pitsidianakis Reviewed-by: Hanna Czenczek Signed-off-by: Stefan Hajnoczi --- hw/block/virtio-blk.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/hw/block/virtio-blk.c b/hw/block/virtio-blk.c index e430ba583c..31212506ca 100644 --- a/hw/block/virtio-blk.c +++ b/hw/block/virtio-blk.c @@ -1209,6 +1209,8 @@ static void virtio_blk_dma_restart_cb(void *opaque, bool running, VirtIOBlockReq *next = rq->next; uint16_t idx = virtio_get_queue_index(rq->vq); + /* Only num_queues vqs were created so vq_rq[idx] is within bounds */ + assert(idx < num_queues); rq->next = vq_rq[idx]; vq_rq[idx] = rq; rq = next; From patchwork Tue Feb 6 19:06:09 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Hajnoczi X-Patchwork-Id: 13547741 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 59E9DC4829D for ; Tue, 6 Feb 2024 19:07:17 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1rXQmF-0008MM-Oz; Tue, 06 Feb 2024 14:06:39 -0500 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 1rXQm7-0008Jt-UU for qemu-devel@nongnu.org; Tue, 06 Feb 2024 14:06:31 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1rXQm6-0000gL-Fn for qemu-devel@nongnu.org; Tue, 06 Feb 2024 14:06:31 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1707246389; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=BspMP2XhVnuC25UhdGg6B1NiDSHrFczqg/Tx0/MfIc4=; b=Ah1+k8bj+6HZef3RW8DUZlzvZPS/xKpmJ3MetwOIz2ZIWeQxAuNSRw/7KteOM1izz98U0N Gh+i0Tq/5jjxABDiYhD5zC/k8HISpLGi180t53Qqha9UYQ+uhsyQysxqaU5JNvXxfz07mg 8EHvBRIMx/SL4SsehJjjmbg5d8JYis8= 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-499-5kxhLAlGMFG_OWzupPn1mQ-1; Tue, 06 Feb 2024 14:06:27 -0500 X-MC-Unique: 5kxhLAlGMFG_OWzupPn1mQ-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.rdu2.redhat.com [10.11.54.7]) (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 1332628EC120; Tue, 6 Feb 2024 19:06:23 +0000 (UTC) Received: from localhost (unknown [10.39.192.41]) by smtp.corp.redhat.com (Postfix) with ESMTP id 77C111C0652C; Tue, 6 Feb 2024 19:06:22 +0000 (UTC) From: Stefan Hajnoczi To: qemu-devel@nongnu.org Cc: Stefan Hajnoczi , Michael Roth , Kevin Wolf , "Michael S. Tsirkin" , Markus Armbruster , Hanna Reitz , qemu-block@nongnu.org, Manos Pitsidianakis Subject: [PATCH v2 4/5] virtio-blk: declare VirtIOBlock::rq with a type Date: Tue, 6 Feb 2024 14:06:09 -0500 Message-ID: <20240206190610.107963-5-stefanha@redhat.com> In-Reply-To: <20240206190610.107963-1-stefanha@redhat.com> References: <20240206190610.107963-1-stefanha@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.7 Received-SPF: pass client-ip=170.10.129.124; envelope-from=stefanha@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -23 X-Spam_score: -2.4 X-Spam_bar: -- X-Spam_report: (-2.4 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.294, 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_H2=-0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 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 The VirtIOBlock::rq field has had the type void * since its introduction in commit 869a5c6df19a ("Stop VM on error in virtio-blk. (Gleb Natapov)"). Perhaps this was done to avoid the forward declaration of VirtIOBlockReq. Hanna Czenczek pointed out the missing type. Specify the actual type because there is no need to use void * here. Suggested-by: Hanna Czenczek Reviewed-by: Manos Pitsidianakis Reviewed-by: Hanna Czenczek Signed-off-by: Stefan Hajnoczi --- include/hw/virtio/virtio-blk.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/include/hw/virtio/virtio-blk.h b/include/hw/virtio/virtio-blk.h index 833a9a344f..5c14110c4b 100644 --- a/include/hw/virtio/virtio-blk.h +++ b/include/hw/virtio/virtio-blk.h @@ -55,7 +55,7 @@ struct VirtIOBlock { VirtIODevice parent_obj; BlockBackend *blk; QemuMutex rq_lock; - void *rq; /* protected by rq_lock */ + struct VirtIOBlockReq *rq; /* protected by rq_lock */ VirtIOBlkConf conf; unsigned short sector_mask; bool original_wce; From patchwork Tue Feb 6 19:06:10 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Hajnoczi X-Patchwork-Id: 13547743 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 5622FC4828D for ; Tue, 6 Feb 2024 19:07:17 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1rXQmF-0008MY-T2; Tue, 06 Feb 2024 14:06:40 -0500 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 1rXQm9-0008LZ-QW for qemu-devel@nongnu.org; Tue, 06 Feb 2024 14:06:35 -0500 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 1rXQm8-0000gk-9O for qemu-devel@nongnu.org; Tue, 06 Feb 2024 14:06:33 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1707246391; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=jHxx7Y1CaQKC5d5CZ/TuSjaYs36sXCT1kADYNwNRTnM=; b=MiRP5/imbsxu5ddbyXoYkLugmUmoWwe9G7Wz4sTpChuLkhqJ//R5dABGwpZrqTFw8UoZwV DrzvHFEGY3mTXu0uWBBgASejiqyqdTiPGll0sDEdOk2hlw7zvH2+NYzN6Ox/Ev0CB+PGre nbSTBSC8binvKmzBvBrskqlwwS3LUFA= 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-518-SDy16ovqN7OUT7FEDmw9nA-1; Tue, 06 Feb 2024 14:06:26 -0500 X-MC-Unique: SDy16ovqN7OUT7FEDmw9nA-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.rdu2.redhat.com [10.11.54.3]) (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 6EAD43804539; Tue, 6 Feb 2024 19:06:25 +0000 (UTC) Received: from localhost (unknown [10.39.192.41]) by smtp.corp.redhat.com (Postfix) with ESMTP id CACE9112132A; Tue, 6 Feb 2024 19:06:24 +0000 (UTC) From: Stefan Hajnoczi To: qemu-devel@nongnu.org Cc: Stefan Hajnoczi , Michael Roth , Kevin Wolf , "Michael S. Tsirkin" , Markus Armbruster , Hanna Reitz , qemu-block@nongnu.org, Manos Pitsidianakis Subject: [PATCH v2 5/5] monitor: use aio_co_reschedule_self() Date: Tue, 6 Feb 2024 14:06:10 -0500 Message-ID: <20240206190610.107963-6-stefanha@redhat.com> In-Reply-To: <20240206190610.107963-1-stefanha@redhat.com> References: <20240206190610.107963-1-stefanha@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.3 Received-SPF: pass client-ip=170.10.133.124; envelope-from=stefanha@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -23 X-Spam_score: -2.4 X-Spam_bar: -- X-Spam_report: (-2.4 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.294, 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_H5=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=unavailable 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 The aio_co_reschedule_self() API is designed to avoid the race condition between scheduling the coroutine in another AioContext and yielding. The QMP dispatch code uses the open-coded version that appears susceptible to the race condition at first glance: aio_co_schedule(qemu_get_aio_context(), qemu_coroutine_self()); qemu_coroutine_yield(); The code is actually safe because the iohandler and qemu_aio_context AioContext run under the Big QEMU Lock. Nevertheless, set a good example and use aio_co_reschedule_self() so it's obvious that there is no race. Suggested-by: Hanna Reitz Reviewed-by: Manos Pitsidianakis Reviewed-by: Hanna Czenczek Signed-off-by: Stefan Hajnoczi --- qapi/qmp-dispatch.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-) diff --git a/qapi/qmp-dispatch.c b/qapi/qmp-dispatch.c index 176b549473..f3488afeef 100644 --- a/qapi/qmp-dispatch.c +++ b/qapi/qmp-dispatch.c @@ -212,8 +212,7 @@ QDict *coroutine_mixed_fn qmp_dispatch(const QmpCommandList *cmds, QObject *requ * executing the command handler so that it can make progress if it * involves an AIO_WAIT_WHILE(). */ - aio_co_schedule(qemu_get_aio_context(), qemu_coroutine_self()); - qemu_coroutine_yield(); + aio_co_reschedule_self(qemu_get_aio_context()); } monitor_set_cur(qemu_coroutine_self(), cur_mon); @@ -227,9 +226,7 @@ QDict *coroutine_mixed_fn qmp_dispatch(const QmpCommandList *cmds, QObject *requ * Move back to iohandler_ctx so that nested event loops for * qemu_aio_context don't start new monitor commands. */ - aio_co_schedule(iohandler_get_aio_context(), - qemu_coroutine_self()); - qemu_coroutine_yield(); + aio_co_reschedule_self(iohandler_get_aio_context()); } } else { /*