From patchwork Mon Feb 5 17:26:55 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Hajnoczi X-Patchwork-Id: 13545905 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 E3097C48292 for ; Mon, 5 Feb 2024 17:28:27 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1rX2kR-0008Rq-EQ; Mon, 05 Feb 2024 12:27:11 -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 1rX2kP-0008Qt-9q for qemu-devel@nongnu.org; Mon, 05 Feb 2024 12:27:09 -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 1rX2kN-0006NT-F8 for qemu-devel@nongnu.org; Mon, 05 Feb 2024 12:27:08 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1707154025; 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=s+Olr8PH+SpG6VKCxoPkaEw13E9gSedLrCjjLcbD7Uk=; b=NkU3yEEOo2SasXEG/X+nGVZ6HP49M8K5kzjEeBd8kEX+V9YQ9S3lyYdIc3VJLrmAmkYz3Q B40Lfu9j/wtC0l4NzEXPnz14COVtARpi3FhRNg6A83zRNLX6vDpdhLFbR1FMhdPYEnHvka 4JxxqQKUXJMRFUHHI1NfbK/XEST9ddg= 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-30-ywBkClvTN3OWfPuMI21XDA-1; Mon, 05 Feb 2024 12:27:04 -0500 X-MC-Unique: ywBkClvTN3OWfPuMI21XDA-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.rdu2.redhat.com [10.11.54.1]) (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 0890488CC44; Mon, 5 Feb 2024 17:27:04 +0000 (UTC) Received: from localhost (unknown [10.39.192.69]) by smtp.corp.redhat.com (Postfix) with ESMTP id 6B24C3C2E; Mon, 5 Feb 2024 17:27:03 +0000 (UTC) From: Stefan Hajnoczi To: qemu-devel@nongnu.org Cc: Kevin Wolf , Hanna Reitz , "Michael S. Tsirkin" , Michael Roth , Markus Armbruster , Stefan Hajnoczi , qemu-block@nongnu.org Subject: [PATCH 1/5] virtio-blk: enforce iothread-vq-mapping validation Date: Mon, 5 Feb 2024 12:26:55 -0500 Message-ID: <20240205172659.476970-2-stefanha@redhat.com> In-Reply-To: <20240205172659.476970-1-stefanha@redhat.com> References: <20240205172659.476970-1-stefanha@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.1 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=-0.285, 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=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 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 | 192 +++++++++++++++++++++++------------------- 1 file changed, 107 insertions(+), 85 deletions(-) diff --git a/hw/block/virtio-blk.c b/hw/block/virtio-blk.c index 227d83569f..e8b37fd5f4 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 +1681,14 @@ 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) { + if (conf->iothread) { + 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 +1714,14 @@ 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 +2031,6 @@ 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 Mon Feb 5 17:26:56 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Hajnoczi X-Patchwork-Id: 13545901 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 41BBFC48297 for ; Mon, 5 Feb 2024 17:27:56 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1rX2kU-0008T2-PH; Mon, 05 Feb 2024 12:27:14 -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 1rX2kT-0008SS-6N for qemu-devel@nongnu.org; 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Mon, 05 Feb 2024 12:27:06 -0500 X-MC-Unique: Q02IBcttM-aduO3i-vy56A-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 8FDE31C05EC0; Mon, 5 Feb 2024 17:27:06 +0000 (UTC) Received: from localhost (unknown [10.39.192.69]) by smtp.corp.redhat.com (Postfix) with ESMTP id 0DFAA492BC6; Mon, 5 Feb 2024 17:27:05 +0000 (UTC) From: Stefan Hajnoczi To: qemu-devel@nongnu.org Cc: Kevin Wolf , Hanna Reitz , "Michael S. Tsirkin" , Michael Roth , Markus Armbruster , Stefan Hajnoczi , qemu-block@nongnu.org Subject: [PATCH 2/5] virtio-blk: clarify that there is at least 1 virtqueue Date: Mon, 5 Feb 2024 12:26:56 -0500 Message-ID: <20240205172659.476970-3-stefanha@redhat.com> In-Reply-To: <20240205172659.476970-1-stefanha@redhat.com> References: <20240205172659.476970-1-stefanha@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.9 Received-SPF: pass client-ip=170.10.129.124; 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=-0.285, 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=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 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 Signed-off-by: Stefan Hajnoczi Reviewed-by: Manos Pitsidianakis Reviewed-by: Hanna Czenczek --- 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 e8b37fd5f4..a0735a9bca 100644 --- a/hw/block/virtio-blk.c +++ b/hw/block/virtio-blk.c @@ -1825,6 +1825,7 @@ 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 Mon Feb 5 17:26:57 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Hajnoczi X-Patchwork-Id: 13545904 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 3EC5CC4828D for ; Mon, 5 Feb 2024 17:28:22 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1rX2kW-0008Tk-Af; Mon, 05 Feb 2024 12:27:16 -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 1rX2kU-0008Si-9h for qemu-devel@nongnu.org; Mon, 05 Feb 2024 12:27:14 -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 1rX2kS-0006Oa-8G for qemu-devel@nongnu.org; Mon, 05 Feb 2024 12:27:14 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1707154031; 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=iAGCvQx28RrLJakkek/T62S1VRBhS+KJNVJlhZaHy24=; b=fp9E2h9lDB4aJMuN59DtNnyPKIw4VUdFRwNVDvH8Dey1fRFwvVMvtPpp9Eu/3zVSPSC8UF 3QSNHNOeT+nzXm5AiGV81Dk8vk7nTe+hv6DgtJCIXzTfoOvZSXy9bhS9dAjq0LpioQbtrR eRoniCDsM2CpOMpBPPU3ibGaFdW60v8= 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-6-qU1hgiJTOumHvQJHYM0ajw-1; Mon, 05 Feb 2024 12:27:09 -0500 X-MC-Unique: qU1hgiJTOumHvQJHYM0ajw-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 C2CD2299E741; Mon, 5 Feb 2024 17:27:08 +0000 (UTC) Received: from localhost (unknown [10.39.192.69]) by smtp.corp.redhat.com (Postfix) with ESMTP id 339541C060AF; Mon, 5 Feb 2024 17:27:07 +0000 (UTC) From: Stefan Hajnoczi To: qemu-devel@nongnu.org Cc: Kevin Wolf , Hanna Reitz , "Michael S. Tsirkin" , Michael Roth , Markus Armbruster , Stefan Hajnoczi , qemu-block@nongnu.org Subject: [PATCH 3/5] virtio-blk: add vq_rq[] bounds check in virtio_blk_dma_restart_cb() Date: Mon, 5 Feb 2024 12:26:57 -0500 Message-ID: <20240205172659.476970-4-stefanha@redhat.com> In-Reply-To: <20240205172659.476970-1-stefanha@redhat.com> References: <20240205172659.476970-1-stefanha@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.7 Received-SPF: pass client-ip=170.10.133.124; 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=-0.285, 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=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 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 Signed-off-by: Stefan Hajnoczi Reviewed-by: Manos Pitsidianakis Reviewed-by: Hanna Czenczek --- 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 a0735a9bca..f3193f4b75 100644 --- a/hw/block/virtio-blk.c +++ b/hw/block/virtio-blk.c @@ -1209,6 +1209,7 @@ static void virtio_blk_dma_restart_cb(void *opaque, bool running, VirtIOBlockReq *next = rq->next; uint16_t idx = virtio_get_queue_index(rq->vq); + assert(idx < num_queues); rq->next = vq_rq[idx]; vq_rq[idx] = rq; rq = next; From patchwork Mon Feb 5 17:26:58 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Hajnoczi X-Patchwork-Id: 13545903 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 1C438C48292 for ; Mon, 5 Feb 2024 17:28:22 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1rX2kZ-0008Up-C1; Mon, 05 Feb 2024 12:27:19 -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 1rX2kW-0008U2-Rx for qemu-devel@nongnu.org; Mon, 05 Feb 2024 12:27:16 -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 1rX2kV-0006PD-7A for qemu-devel@nongnu.org; Mon, 05 Feb 2024 12:27:16 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1707154034; 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=Iwp2QqzatCi+TDpvTEyZk16/6wtwxHMAzXsBgQOM+Fg=; b=G9P9F3r+NaJXxXZ/IwIipPjsHFPx886xmdZR4BU/Lp8Hg0n0FVDJJzZi3GBq1WFpfQTu7t EH0lZq3hML4h5EXsO6yMMLPMP3PLl0WODqciQRIXbUbbq1Mwk6KZE56aLErfyzLMgMnkV1 9YE2fhfRbhBrrIXMaoeZm6Uq5j7TqFU= 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-613-LT_1W9WVMa2eSZSpMLBAJQ-1; Mon, 05 Feb 2024 12:27:11 -0500 X-MC-Unique: LT_1W9WVMa2eSZSpMLBAJQ-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 BFA133C000AD; Mon, 5 Feb 2024 17:27:10 +0000 (UTC) Received: from localhost (unknown [10.39.192.69]) by smtp.corp.redhat.com (Postfix) with ESMTP id 38B1F1121313; Mon, 5 Feb 2024 17:27:10 +0000 (UTC) From: Stefan Hajnoczi To: qemu-devel@nongnu.org Cc: Kevin Wolf , Hanna Reitz , "Michael S. Tsirkin" , Michael Roth , Markus Armbruster , Stefan Hajnoczi , qemu-block@nongnu.org Subject: [PATCH 4/5] virtio-blk: declare VirtIOBlock::rq with a type Date: Mon, 5 Feb 2024 12:26:58 -0500 Message-ID: <20240205172659.476970-5-stefanha@redhat.com> In-Reply-To: <20240205172659.476970-1-stefanha@redhat.com> References: <20240205172659.476970-1-stefanha@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.3 Received-SPF: pass client-ip=170.10.129.124; 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=-0.285, 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 Signed-off-by: Stefan Hajnoczi Reviewed-by: Manos Pitsidianakis Reviewed-by: Hanna Czenczek --- 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 Mon Feb 5 17:26:59 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Hajnoczi X-Patchwork-Id: 13545902 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 3E253C48292 for ; Mon, 5 Feb 2024 17:27:56 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1rX2kc-0008W8-31; Mon, 05 Feb 2024 12:27:22 -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 1rX2kb-0008Vg-2Q for qemu-devel@nongnu.org; Mon, 05 Feb 2024 12:27:21 -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 1rX2kZ-0006Pv-OW for qemu-devel@nongnu.org; Mon, 05 Feb 2024 12:27:20 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1707154039; 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=MoN0Ki9v/7+vDB+dfSjCp/PaiJqIVFi6SHTUNYHmlaI=; b=b92UeApq5T5bOaJNA7SPZeQbi78UhE89MCzP8iUrreik9nH9nt+0Pxho/pr/UE++fV6RYy Kj0AZHW11dzBUuSvZBZrFpkxxsDlw+936hf5cTGN5l6r0hXKCYYM7Hgofv9FrAKO0vCH/p svZamQoq/rdKjmkseTEGh/hYjJVLUWw= 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-441-eawk-JpHON6cgFnjiaL3nQ-1; Mon, 05 Feb 2024 12:27:13 -0500 X-MC-Unique: eawk-JpHON6cgFnjiaL3nQ-1 Received: from smtp.corp.redhat.com (int-mx10.intmail.prod.int.rdu2.redhat.com [10.11.54.10]) (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 85B4510B7261; Mon, 5 Feb 2024 17:27:13 +0000 (UTC) Received: from localhost (unknown [10.39.192.69]) by smtp.corp.redhat.com (Postfix) with ESMTP id DFC06492BFA; Mon, 5 Feb 2024 17:27:12 +0000 (UTC) From: Stefan Hajnoczi To: qemu-devel@nongnu.org Cc: Kevin Wolf , Hanna Reitz , "Michael S. Tsirkin" , Michael Roth , Markus Armbruster , Stefan Hajnoczi , qemu-block@nongnu.org Subject: [PATCH 5/5] monitor: use aio_co_reschedule_self() Date: Mon, 5 Feb 2024 12:26:59 -0500 Message-ID: <20240205172659.476970-6-stefanha@redhat.com> In-Reply-To: <20240205172659.476970-1-stefanha@redhat.com> References: <20240205172659.476970-1-stefanha@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.10 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=-0.285, 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=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 Signed-off-by: Stefan Hajnoczi Reviewed-by: Manos Pitsidianakis Reviewed-by: Hanna Czenczek Acked-by: Markus Armbruster --- 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 { /*