From patchwork Tue Mar 11 16:00:20 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kevin Wolf X-Patchwork-Id: 14012268 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 AD577C282EC for ; Tue, 11 Mar 2025 16:14:45 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ts2Bc-00061E-Nr; Tue, 11 Mar 2025 12:10:35 -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 1ts22p-0004Wy-8j for qemu-devel@nongnu.org; Tue, 11 Mar 2025 12:01:35 -0400 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 1ts22h-0005pO-LK for qemu-devel@nongnu.org; Tue, 11 Mar 2025 12:01:22 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1741708875; 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=OeBbLzT2TofkNhRYH5+kh6JTgvIl0D7nG0iqsPQZ9bo=; b=Ecs01LawtLF0oU3XhGziwnKDbhp9wD/kKkLhdpYbpOi3FOZeSCKSoY86IaCPUJX44pCn84 PxtagTB3K21bnf6TowgihS+Y2TWME+XioTcdq3pRfXeyTV0QB0Q68O+GWo3EC9wEOGCh/o TIk61ualqIhzH+3tfkumKMWFHe9qiT8= Received: from mx-prod-mc-06.mail-002.prod.us-west-2.aws.redhat.com (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-657-rYI0a860NvWRnkicR9DsGw-1; Tue, 11 Mar 2025 12:01:11 -0400 X-MC-Unique: rYI0a860NvWRnkicR9DsGw-1 X-Mimecast-MFC-AGG-ID: rYI0a860NvWRnkicR9DsGw_1741708870 Received: from mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.93]) (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 mx-prod-mc-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id A0C0B180035E; Tue, 11 Mar 2025 16:01:10 +0000 (UTC) Received: from merkur.redhat.com (unknown [10.44.33.18]) by mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 07DDF1800373; Tue, 11 Mar 2025 16:01:08 +0000 (UTC) From: Kevin Wolf To: qemu-block@nongnu.org Cc: kwolf@redhat.com, stefanha@redhat.com, qemu-devel@nongnu.org Subject: [PULL 21/22] virtio-scsi: handle ctrl virtqueue in main loop Date: Tue, 11 Mar 2025 17:00:20 +0100 Message-ID: <20250311160021.349761-22-kwolf@redhat.com> In-Reply-To: <20250311160021.349761-1-kwolf@redhat.com> References: <20250311160021.349761-1-kwolf@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.93 Received-SPF: pass client-ip=170.10.129.124; envelope-from=kwolf@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, 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, RCVD_IN_VALIDITY_CERTIFIED_BLOCKED=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=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: 2.1.29 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 From: Stefan Hajnoczi Previously the ctrl virtqueue was handled in the AioContext where SCSI requests are processed. When IOThread Virtqueue Mapping was added things become more complicated because SCSI requests could run in other AioContexts. Simplify by handling the ctrl virtqueue in the main loop where reset operations can be performed. Note that BHs are still used canceling SCSI requests in their AioContexts but at least the mean loop activity doesn't need BHs anymore. Signed-off-by: Stefan Hajnoczi Message-ID: <20250311132616.1049687-13-stefanha@redhat.com> Signed-off-by: Kevin Wolf --- include/hw/virtio/virtio-scsi.h | 8 -- hw/scsi/virtio-scsi-dataplane.c | 6 ++ hw/scsi/virtio-scsi.c | 144 ++++++-------------------------- 3 files changed, 33 insertions(+), 125 deletions(-) diff --git a/include/hw/virtio/virtio-scsi.h b/include/hw/virtio/virtio-scsi.h index 086201efa2..31e852ed6c 100644 --- a/include/hw/virtio/virtio-scsi.h +++ b/include/hw/virtio/virtio-scsi.h @@ -90,14 +90,6 @@ struct VirtIOSCSI { QemuMutex ctrl_lock; /* protects ctrl_vq */ - /* - * TMFs deferred to main loop BH. These fields are protected by - * tmf_bh_lock. - */ - QemuMutex tmf_bh_lock; - QEMUBH *tmf_bh; - QTAILQ_HEAD(, VirtIOSCSIReq) tmf_bh_list; - /* Fields for dataplane below */ AioContext **vq_aio_context; /* per-virtqueue AioContext pointer */ diff --git a/hw/scsi/virtio-scsi-dataplane.c b/hw/scsi/virtio-scsi-dataplane.c index 6bb368c8a5..2d37fa6712 100644 --- a/hw/scsi/virtio-scsi-dataplane.c +++ b/hw/scsi/virtio-scsi-dataplane.c @@ -73,6 +73,12 @@ void virtio_scsi_dataplane_setup(VirtIOSCSI *s, Error **errp) s->vq_aio_context[i] = ctx; } } + + /* + * Always handle the ctrl virtqueue in the main loop thread where device + * resets can be performed. + */ + s->vq_aio_context[0] = qemu_get_aio_context(); } /* Context: BQL held */ diff --git a/hw/scsi/virtio-scsi.c b/hw/scsi/virtio-scsi.c index 9f61eb97db..d9c32c3245 100644 --- a/hw/scsi/virtio-scsi.c +++ b/hw/scsi/virtio-scsi.c @@ -319,115 +319,6 @@ static void virtio_scsi_cancel_notify(Notifier *notifier, void *data) g_free(n); } -static void virtio_scsi_do_one_tmf_bh(VirtIOSCSIReq *req) -{ - VirtIOSCSI *s = req->dev; - SCSIDevice *d = virtio_scsi_device_get(s, req->req.tmf.lun); - BusChild *kid; - int target; - - switch (req->req.tmf.subtype) { - case VIRTIO_SCSI_T_TMF_LOGICAL_UNIT_RESET: - if (!d) { - req->resp.tmf.response = VIRTIO_SCSI_S_BAD_TARGET; - goto out; - } - if (d->lun != virtio_scsi_get_lun(req->req.tmf.lun)) { - req->resp.tmf.response = VIRTIO_SCSI_S_INCORRECT_LUN; - goto out; - } - qatomic_inc(&s->resetting); - device_cold_reset(&d->qdev); - qatomic_dec(&s->resetting); - break; - - case VIRTIO_SCSI_T_TMF_I_T_NEXUS_RESET: - target = req->req.tmf.lun[1]; - qatomic_inc(&s->resetting); - - rcu_read_lock(); - QTAILQ_FOREACH_RCU(kid, &s->bus.qbus.children, sibling) { - SCSIDevice *d1 = SCSI_DEVICE(kid->child); - if (d1->channel == 0 && d1->id == target) { - device_cold_reset(&d1->qdev); - } - } - rcu_read_unlock(); - - qatomic_dec(&s->resetting); - break; - - default: - g_assert_not_reached(); - } - -out: - object_unref(OBJECT(d)); - virtio_scsi_complete_req(req, &s->ctrl_lock); -} - -/* Some TMFs must be processed from the main loop thread */ -static void virtio_scsi_do_tmf_bh(void *opaque) -{ - VirtIOSCSI *s = opaque; - QTAILQ_HEAD(, VirtIOSCSIReq) reqs = QTAILQ_HEAD_INITIALIZER(reqs); - VirtIOSCSIReq *req; - VirtIOSCSIReq *tmp; - - GLOBAL_STATE_CODE(); - - WITH_QEMU_LOCK_GUARD(&s->tmf_bh_lock) { - QTAILQ_FOREACH_SAFE(req, &s->tmf_bh_list, next, tmp) { - QTAILQ_REMOVE(&s->tmf_bh_list, req, next); - QTAILQ_INSERT_TAIL(&reqs, req, next); - } - - qemu_bh_delete(s->tmf_bh); - s->tmf_bh = NULL; - } - - QTAILQ_FOREACH_SAFE(req, &reqs, next, tmp) { - QTAILQ_REMOVE(&reqs, req, next); - virtio_scsi_do_one_tmf_bh(req); - } -} - -static void virtio_scsi_reset_tmf_bh(VirtIOSCSI *s) -{ - VirtIOSCSIReq *req; - VirtIOSCSIReq *tmp; - - GLOBAL_STATE_CODE(); - - /* Called after ioeventfd has been stopped, so tmf_bh_lock is not needed */ - if (s->tmf_bh) { - qemu_bh_delete(s->tmf_bh); - s->tmf_bh = NULL; - } - - QTAILQ_FOREACH_SAFE(req, &s->tmf_bh_list, next, tmp) { - QTAILQ_REMOVE(&s->tmf_bh_list, req, next); - - /* SAM-6 6.3.2 Hard reset */ - req->resp.tmf.response = VIRTIO_SCSI_S_TARGET_FAILURE; - virtio_scsi_complete_req(req, &req->dev->ctrl_lock); - } -} - -static void virtio_scsi_defer_tmf_to_main_loop(VirtIOSCSIReq *req) -{ - VirtIOSCSI *s = req->dev; - - WITH_QEMU_LOCK_GUARD(&s->tmf_bh_lock) { - QTAILQ_INSERT_TAIL(&s->tmf_bh_list, req, next); - - if (!s->tmf_bh) { - s->tmf_bh = qemu_bh_new(virtio_scsi_do_tmf_bh, s); - qemu_bh_schedule(s->tmf_bh); - } - } -} - static void virtio_scsi_tmf_cancel_req(VirtIOSCSIReq *tmf, SCSIRequest *r) { VirtIOSCSICancelNotifier *notifier; @@ -627,11 +518,35 @@ static int virtio_scsi_do_tmf(VirtIOSCSI *s, VirtIOSCSIReq *req) break; case VIRTIO_SCSI_T_TMF_LOGICAL_UNIT_RESET: - case VIRTIO_SCSI_T_TMF_I_T_NEXUS_RESET: - virtio_scsi_defer_tmf_to_main_loop(req); - ret = -EINPROGRESS; + if (!d) { + goto fail; + } + if (d->lun != virtio_scsi_get_lun(req->req.tmf.lun)) { + goto incorrect_lun; + } + qatomic_inc(&s->resetting); + device_cold_reset(&d->qdev); + qatomic_dec(&s->resetting); break; + case VIRTIO_SCSI_T_TMF_I_T_NEXUS_RESET: { + BusChild *kid; + int target = req->req.tmf.lun[1]; + qatomic_inc(&s->resetting); + + rcu_read_lock(); + QTAILQ_FOREACH_RCU(kid, &s->bus.qbus.children, sibling) { + SCSIDevice *d1 = SCSI_DEVICE(kid->child); + if (d1->channel == 0 && d1->id == target) { + device_cold_reset(&d1->qdev); + } + } + rcu_read_unlock(); + + qatomic_dec(&s->resetting); + break; + } + case VIRTIO_SCSI_T_TMF_ABORT_TASK_SET: case VIRTIO_SCSI_T_TMF_CLEAR_TASK_SET: { g_autoptr(GHashTable) aio_contexts = g_hash_table_new(NULL, NULL); @@ -1087,7 +1002,6 @@ static void virtio_scsi_reset(VirtIODevice *vdev) assert(!s->dataplane_started); - virtio_scsi_reset_tmf_bh(s); virtio_scsi_flush_defer_tmf_to_aio_context(s); qatomic_inc(&s->resetting); @@ -1402,10 +1316,8 @@ static void virtio_scsi_device_realize(DeviceState *dev, Error **errp) VirtIOSCSI *s = VIRTIO_SCSI(dev); Error *err = NULL; - QTAILQ_INIT(&s->tmf_bh_list); qemu_mutex_init(&s->ctrl_lock); qemu_mutex_init(&s->event_lock); - qemu_mutex_init(&s->tmf_bh_lock); virtio_scsi_common_realize(dev, virtio_scsi_handle_ctrl, @@ -1445,11 +1357,9 @@ static void virtio_scsi_device_unrealize(DeviceState *dev) { VirtIOSCSI *s = VIRTIO_SCSI(dev); - virtio_scsi_reset_tmf_bh(s); virtio_scsi_dataplane_cleanup(s); qbus_set_hotplug_handler(BUS(&s->bus), NULL); virtio_scsi_common_unrealize(dev); - qemu_mutex_destroy(&s->tmf_bh_lock); qemu_mutex_destroy(&s->event_lock); qemu_mutex_destroy(&s->ctrl_lock); }