From patchwork Thu Dec 22 06:04:26 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jason Wang X-Patchwork-Id: 13079439 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7EDB3C4332F for ; Thu, 22 Dec 2022 06:06:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235068AbiLVGGe (ORCPT ); Thu, 22 Dec 2022 01:06:34 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47912 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235087AbiLVGGM (ORCPT ); Thu, 22 Dec 2022 01:06:12 -0500 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3E0DA1B1FD for ; Wed, 21 Dec 2022 22:05:00 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1671689099; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=3AagJqkYYDM80wKW6v4HoTlfL3zWbTRSgD3VOT9tZZo=; b=U/l7PCNOVp5nEdyFhIRzM4RFzXTa4SnKcHX7sJ066Dz+YP6QVY1F8QurLT3V00XSKfy6yd 9ppY0H0MP+HLt4o7qIVokekQ9aMOqljcugr87n6hzR/54idceEwmEHS5HBvxDkqX67C3xY 65VGP+aE72nKqbd84DPPGGK+zfhnbKc= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-638-LoPDdRuFMEmvKTedKAP_YA-1; Thu, 22 Dec 2022 01:04:55 -0500 X-MC-Unique: LoPDdRuFMEmvKTedKAP_YA-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.rdu2.redhat.com [10.11.54.3]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 2D0341C04B79; Thu, 22 Dec 2022 06:04:55 +0000 (UTC) Received: from localhost.localdomain (ovpn-13-179.pek2.redhat.com [10.72.13.179]) by smtp.corp.redhat.com (Postfix) with ESMTP id 8B80E112132C; Thu, 22 Dec 2022 06:04:49 +0000 (UTC) From: Jason Wang To: mst@redhat.com, jasowang@redhat.com Cc: davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, virtualization@lists.linux-foundation.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, maxime.coquelin@redhat.com, alvaro.karsz@solid-run.com, eperezma@redhat.com Subject: [RFC PATCH 3/4] virtio_ring: introduce a per virtqueue waitqueue Date: Thu, 22 Dec 2022 14:04:26 +0800 Message-Id: <20221222060427.21626-4-jasowang@redhat.com> In-Reply-To: <20221222060427.21626-1-jasowang@redhat.com> References: <20221222060427.21626-1-jasowang@redhat.com> MIME-Version: 1.0 Content-type: text/plain X-Scanned-By: MIMEDefang 3.1 on 10.11.54.3 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-State: RFC This patch introduces a per virtqueue waitqueue to allow driver to sleep and wait for more used. Two new helpers are introduced to allow driver to sleep and wake up. Signed-off-by: Jason Wang --- drivers/virtio/virtio_ring.c | 31 +++++++++++++++++++++++++++++++ include/linux/virtio.h | 4 ++++ 2 files changed, 35 insertions(+) diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c index 90c2034a77f3..4a2d5ac30b0f 100644 --- a/drivers/virtio/virtio_ring.c +++ b/drivers/virtio/virtio_ring.c @@ -13,6 +13,7 @@ #include #include #include +#include #include #ifdef DEBUG @@ -59,6 +60,7 @@ dev_err(&_vq->vq.vdev->dev, \ "%s:"fmt, (_vq)->vq.name, ##args); \ (_vq)->broken = true; \ + wake_up_interruptible(&(_vq)->wq); \ } while (0) #define START_USE(vq) #define END_USE(vq) @@ -202,6 +204,9 @@ struct vring_virtqueue { /* DMA, allocation, and size information */ bool we_own_ring; + /* Wait for buffer to be used */ + wait_queue_head_t wq; + #ifdef DEBUG /* They're supposed to lock for us. */ unsigned int in_use; @@ -2023,6 +2028,8 @@ static struct virtqueue *vring_create_virtqueue_packed( if (virtio_has_feature(vdev, VIRTIO_F_ORDER_PLATFORM)) vq->weak_barriers = false; + init_waitqueue_head(&vq->wq); + err = vring_alloc_state_extra_packed(&vring_packed); if (err) goto err_state_extra; @@ -2516,6 +2523,8 @@ static struct virtqueue *__vring_new_virtqueue(unsigned int index, if (virtio_has_feature(vdev, VIRTIO_F_ORDER_PLATFORM)) vq->weak_barriers = false; + init_waitqueue_head(&vq->wq); + err = vring_alloc_state_extra_split(vring_split); if (err) { kfree(vq); @@ -2653,6 +2662,8 @@ static void vring_free(struct virtqueue *_vq) { struct vring_virtqueue *vq = to_vvq(_vq); + wake_up_interruptible(&vq->wq); + if (vq->we_own_ring) { if (vq->packed_ring) { vring_free_queue(vq->vq.vdev, @@ -2863,4 +2874,24 @@ const struct vring *virtqueue_get_vring(struct virtqueue *vq) } EXPORT_SYMBOL_GPL(virtqueue_get_vring); +int virtqueue_wait_for_used(struct virtqueue *_vq, + unsigned int *len) +{ + struct vring_virtqueue *vq = to_vvq(_vq); + + /* Use a better timeout or simply start from no timeout */ + return wait_event_interruptible_timeout(vq->wq, + virtqueue_get_buf(_vq, len), + HZ); +} +EXPORT_SYMBOL_GPL(virtqueue_wait_for_used); + +void virtqueue_wake_up(struct virtqueue *_vq) +{ + struct vring_virtqueue *vq = to_vvq(_vq); + + wake_up_interruptible(&vq->wq); +} +EXPORT_SYMBOL_GPL(virtqueue_wake_up); + MODULE_LICENSE("GPL"); diff --git a/include/linux/virtio.h b/include/linux/virtio.h index dcab9c7e8784..4df098b8f1ca 100644 --- a/include/linux/virtio.h +++ b/include/linux/virtio.h @@ -72,6 +72,10 @@ void *virtqueue_get_buf(struct virtqueue *vq, unsigned int *len); void *virtqueue_get_buf_ctx(struct virtqueue *vq, unsigned int *len, void **ctx); +int virtqueue_wait_for_used(struct virtqueue *vq, + unsigned int *len); +void virtqueue_wake_up(struct virtqueue *vq); + void virtqueue_disable_cb(struct virtqueue *vq); bool virtqueue_enable_cb(struct virtqueue *vq);