From patchwork Sun Feb 23 15:36:19 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Cindy Lu X-Patchwork-Id: 13987072 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B32D020A5E7 for ; Sun, 23 Feb 2025 15:41:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740325299; cv=none; b=Ox5CGFfw3+oC3Llm8q8Vv2ZPzY6/fWrhDF1dx16qHuY21mcnX4azJpcsEE2o2Ki3vPonRjVo+qH4iPNHljPyMS1aaP/SJcfaDGODkaKboowtU5PxM/v0Y5HfFoo3n5THAXynsykauxVZPv5JswOa/BW2tFYjwodmORuTX0y9Kk4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740325299; c=relaxed/simple; bh=ZXiEdTTDkzwOV/njsO665pJImpsVwviM91yrhio2Vu4=; h=From:To:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=slyDJs+CQHdYG7XRK41Xuj0tJ5pWG1hScJt8TWrtiv0pTqJ8GhwX0EkYjgjg0fwGaF1xhS6YKvhuO67saBCp80sbqF/2K4uZV4OzuPoKB75umbLXwra2AGQ1irU9PIviOpSQ16WRPSh2jzSRoIVCV03SKKw61DNOO1xjVnXGbN8= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=EgbuNogk; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="EgbuNogk" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1740325296; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=S5Ma3bsAkPkhFtnIEw/9PBZEYBfxPhfHkVWn0LCGlvg=; b=EgbuNogkgCts6fPoQmX/vePz7gOHMJR9PO03skGeHObJrEpbGdvQ/jv4PwRiUYXijRrwR2 XHQAwrkfuVfyGaZZxq/bJof0ObDGG5dN5ZZJj4FNjHUrLE5jK/ImbeNl2CRc4umVun0mBP IHCb5Y0/uGn4hyZMrPISBoaKAMeWYUU= Received: from mx-prod-mc-03.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-253-2ENMbybrPVK4rSVx4t1vnA-1; Sun, 23 Feb 2025 10:41:35 -0500 X-MC-Unique: 2ENMbybrPVK4rSVx4t1vnA-1 X-Mimecast-MFC-AGG-ID: 2ENMbybrPVK4rSVx4t1vnA_1740325294 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-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 3AF0219560BC; Sun, 23 Feb 2025 15:41:34 +0000 (UTC) Received: from server.redhat.com (unknown [10.72.112.28]) by mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id B4C251800359; Sun, 23 Feb 2025 15:41:29 +0000 (UTC) From: Cindy Lu To: lulu@redhat.com, jasowang@redhat.com, mst@redhat.com, michael.christie@oracle.com, sgarzare@redhat.com, linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org, netdev@vger.kernel.org Subject: [PATCH v6 4/6] vhost: introduce worker ops to support multiple thread models Date: Sun, 23 Feb 2025 23:36:19 +0800 Message-ID: <20250223154042.556001-5-lulu@redhat.com> In-Reply-To: <20250223154042.556001-1-lulu@redhat.com> References: <20250223154042.556001-1-lulu@redhat.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.93 This commit restores the previously removed functions kthread_wakeup and kthread_stop, and introduces a new ops structure to handle worker wakeup, stop, and creation. The function vhost_worker_create initializes these ops pointers based on the inherit_owner value. Signed-off-by: Cindy Lu --- drivers/vhost/vhost.c | 115 +++++++++++++++++++++++++++++++++++------- drivers/vhost/vhost.h | 12 +++++ 2 files changed, 110 insertions(+), 17 deletions(-) diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index adbb957c8b5f..d8c0ea118bb1 100644 --- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c @@ -243,7 +243,7 @@ static void vhost_worker_queue(struct vhost_worker *worker, * test_and_set_bit() implies a memory barrier. */ llist_add(&work->node, &worker->work_list); - vhost_task_wake(worker->vtsk); + worker->ops->wakeup(worker); } } @@ -697,7 +697,7 @@ static void vhost_worker_destroy(struct vhost_dev *dev, WARN_ON(!llist_empty(&worker->work_list)); xa_erase(&dev->worker_xa, worker->id); - vhost_task_stop(worker->vtsk); + worker->ops->stop(worker); kfree(worker); } @@ -720,42 +720,123 @@ static void vhost_workers_free(struct vhost_dev *dev) xa_destroy(&dev->worker_xa); } +static void vhost_task_wakeup_fn(struct vhost_worker *worker) +{ + return vhost_task_wake(worker->vtsk); +} + +static void vhost_kthread_wakeup_fn(struct vhost_worker *worker) +{ + wake_up_process(worker->kthread_task); +} + +static void vhost_task_stop_fn(struct vhost_worker *worker) +{ + return vhost_task_stop(worker->vtsk); +} + +static void vhost_kthread_stop_fn(struct vhost_worker *worker) +{ + kthread_stop(worker->kthread_task); +} + +static int vhost_task_worker_create_fn(struct vhost_worker *worker, + struct vhost_dev *dev, const char *name) +{ + struct vhost_task *vtsk; + u32 id; + int ret; + + vtsk = vhost_task_create(vhost_run_work_list, vhost_worker_killed, + worker, name); + if (!vtsk) + return -ENOMEM; + + worker->vtsk = vtsk; + vhost_task_start(vtsk); + ret = xa_alloc(&dev->worker_xa, &id, worker, xa_limit_32b, GFP_KERNEL); + if (ret < 0) { + vhost_task_stop_fn(worker); + return ret; + } + worker->id = id; + return 0; +} + +static int kthread_worker_create_fn(struct vhost_worker *worker, + struct vhost_dev *dev, const char *name) +{ + struct task_struct *task; + u32 id; + int ret; + + task = kthread_create(vhost_run_work_kthread_list, worker, "%s", name); + if (IS_ERR(task)) + return PTR_ERR(task); + + worker->kthread_task = task; + wake_up_process(task); + ret = xa_alloc(&dev->worker_xa, &id, worker, xa_limit_32b, GFP_KERNEL); + if (ret < 0) + goto stop_worker; + + ret = vhost_attach_task_to_cgroups(worker); + if (ret) + goto stop_worker; + + worker->id = id; + return 0; + +stop_worker: + vhost_kthread_stop_fn(worker); + return ret; +} + +static const struct vhost_worker_ops vhost_task_ops = { + .create = vhost_task_worker_create_fn, + .stop = vhost_task_stop_fn, + .wakeup = vhost_task_wakeup_fn, +}; + +static const struct vhost_worker_ops kthread_ops = { + .create = kthread_worker_create_fn, + .stop = vhost_kthread_stop_fn, + .wakeup = vhost_kthread_wakeup_fn, +}; + static struct vhost_worker *vhost_worker_create(struct vhost_dev *dev) { struct vhost_worker *worker; - struct vhost_task *vtsk; char name[TASK_COMM_LEN]; int ret; - u32 id; + const struct vhost_worker_ops *ops = + dev->inherit_owner ? &vhost_task_ops : &kthread_ops; worker = kzalloc(sizeof(*worker), GFP_KERNEL_ACCOUNT); if (!worker) return NULL; worker->dev = dev; + worker->ops = ops; snprintf(name, sizeof(name), "vhost-%d", current->pid); - vtsk = vhost_task_create(vhost_run_work_list, vhost_worker_killed, - worker, name); - if (!vtsk) - goto free_worker; - mutex_init(&worker->mutex); init_llist_head(&worker->work_list); worker->kcov_handle = kcov_common_handle(); - worker->vtsk = vtsk; - - vhost_task_start(vtsk); + /* + * If inherit_owner is true we use vhost_tasks to create + * the worker so all settings/limits like cgroups, NPROC, + * scheduler, etc are inherited from the owner. If false, + * we use kthreads and only attach to the same cgroups + * as the owner for compat with older kernels. + */ - ret = xa_alloc(&dev->worker_xa, &id, worker, xa_limit_32b, GFP_KERNEL); + ret = ops->create(worker, dev, name); if (ret < 0) - goto stop_worker; - worker->id = id; + goto free_worker; return worker; -stop_worker: - vhost_task_stop(vtsk); free_worker: kfree(worker); return NULL; diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h index c650c4506c70..029c203147be 100644 --- a/drivers/vhost/vhost.h +++ b/drivers/vhost/vhost.h @@ -26,7 +26,18 @@ struct vhost_work { unsigned long flags; }; +struct vhost_worker; +struct vhost_dev; + +struct vhost_worker_ops { + int (*create)(struct vhost_worker *worker, struct vhost_dev *dev, + const char *name); + void (*stop)(struct vhost_worker *worker); + void (*wakeup)(struct vhost_worker *worker); +}; + struct vhost_worker { + struct task_struct *kthread_task; struct vhost_task *vtsk; struct vhost_dev *dev; /* Used to serialize device wide flushing with worker swapping. */ @@ -36,6 +47,7 @@ struct vhost_worker { u32 id; int attachment_cnt; bool killed; + const struct vhost_worker_ops *ops; }; /* Poll a file (eventfd or socket) */