From patchwork Wed Jul 31 02:59:46 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jason Wang X-Patchwork-Id: 13748015 X-Patchwork-Delegate: kuba@kernel.org 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 38BD222F19 for ; Wed, 31 Jul 2024 03:00:23 +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=1722394825; cv=none; b=ZZIxqXl/1mA1QYRv6CRPs5wwXyCkWGWyhawBEEtslHnyUzPj7PDiUd6ZvS2WE7A2BeCs2m6sH0JQ0T8XVbl6F/mPYW2+h6tNKnryW7UZDdRqGmo0AyAFFqK6/sVR6UIMsR+3+5iCHft5Z4hxtt6uwgo3A83EM2UAu1lsQjhikG8= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722394825; c=relaxed/simple; bh=cMaNuKwtGB66k+wzRP58lh1DkYEBUYnziv7pbA2VBWo=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=WlkOaADH+lXJLSXb8L2rC8LW1FiDeEwN6tBVFAkbVI2INl6iSb6NZqj7YzAhloRs9PXy9xp2X3UdKEQVFAWHrbPasbxBe5kkpSgX0USqdpsMZFbbeX1QkVSdztgufvuF/VIWP5saE4KD38TDiE+BZOK92xeo3yoshfeaxsGKyWQ= 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=hn6IkUE4; 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="hn6IkUE4" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1722394823; 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=fyqGi8WepnDEHHzpJw+aLOomcoq9K5r0l14qL5VCaSg=; b=hn6IkUE479EqJy3sxqSfbVOcIBbvU+tR45zPp3tkUW7xD91rcblR9g2TsG6uCcoEFhgrm6 +n2RUG2UJhoIaNP6B9K9j+03nN7fgzZEGz/6ZNmwTWYB5YHRqwe55hJQqaWYfstKu9COoB 4mnv6lj2HlX8Vny2DO53CCyfGtdw8Hc= Received: from mx-prod-mc-02.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-517-PudfHrkPMIW2XP1Q-fKE7A-1; Tue, 30 Jul 2024 23:00:17 -0400 X-MC-Unique: PudfHrkPMIW2XP1Q-fKE7A-1 Received: from mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.40]) (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-02.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id B392C1955D5C; Wed, 31 Jul 2024 03:00:15 +0000 (UTC) Received: from localhost.localdomain (unknown [10.72.112.247]) by mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id B325A1955D42; Wed, 31 Jul 2024 03:00:08 +0000 (UTC) From: Jason Wang To: mst@redhat.com, jasowang@redhat.com, xuanzhuo@linux.alibaba.com, eperezma@redhat.com, davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, virtualization@lists.linux.dev, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Venkat Venkatsubra , Gia-Khanh Nguyen Subject: [PATCH V4 net-next 2/3] virtio: allow driver to disable the configure change notification Date: Wed, 31 Jul 2024 10:59:46 +0800 Message-ID: <20240731025947.23157-3-jasowang@redhat.com> In-Reply-To: <20240731025947.23157-1-jasowang@redhat.com> References: <20240731025947.23157-1-jasowang@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 3.0 on 10.30.177.40 X-Patchwork-Delegate: kuba@kernel.org Sometime, it would be useful to disable the configure change notification from the driver. So this patch allows this by introducing a variable config_change_driver_disabled and only allow the configure change notification callback to be triggered when it is allowed by both the virtio core and the driver. It is set to false by default to hold the current semantic so we don't need to change any drivers. The first user for this would be virtio-net. Cc: Venkat Venkatsubra Cc: Gia-Khanh Nguyen Signed-off-by: Jason Wang --- drivers/virtio/virtio.c | 39 ++++++++++++++++++++++++++++++++++++--- include/linux/virtio.h | 7 +++++++ 2 files changed, 43 insertions(+), 3 deletions(-) diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c index b24f08ff2a8c..0e9cd580fbdd 100644 --- a/drivers/virtio/virtio.c +++ b/drivers/virtio/virtio.c @@ -127,10 +127,12 @@ static void __virtio_config_changed(struct virtio_device *dev) { struct virtio_driver *drv = drv_to_virtio(dev->dev.driver); - if (!dev->config_core_enabled) + if (!dev->config_core_enabled || dev->config_driver_disabled) dev->config_change_pending = true; - else if (drv && drv->config_changed) + else if (drv && drv->config_changed) { drv->config_changed(dev); + dev->config_change_pending = false; + } } void virtio_config_changed(struct virtio_device *dev) @@ -143,6 +145,38 @@ void virtio_config_changed(struct virtio_device *dev) } EXPORT_SYMBOL_GPL(virtio_config_changed); +/** + * virtio_config_driver_disable - disable config change reporting by drivers + * @dev: the device to reset + * + * This is only allowed to be called by a driver and disalbing can't + * be nested. + */ +void virtio_config_driver_disable(struct virtio_device *dev) +{ + spin_lock_irq(&dev->config_lock); + dev->config_driver_disabled = true; + spin_unlock_irq(&dev->config_lock); +} +EXPORT_SYMBOL_GPL(virtio_config_driver_disable); + +/** + * virtio_config_driver_enable - enable config change reporting by drivers + * @dev: the device to reset + * + * This is only allowed to be called by a driver and enabling can't + * be nested. + */ +void virtio_config_driver_enable(struct virtio_device *dev) +{ + spin_lock_irq(&dev->config_lock); + dev->config_driver_disabled = false; + if (dev->config_change_pending) + __virtio_config_changed(dev); + spin_unlock_irq(&dev->config_lock); +} +EXPORT_SYMBOL_GPL(virtio_config_driver_enable); + static void virtio_config_core_disable(struct virtio_device *dev) { spin_lock_irq(&dev->config_lock); @@ -156,7 +190,6 @@ static void virtio_config_core_enable(struct virtio_device *dev) dev->config_core_enabled = true; if (dev->config_change_pending) __virtio_config_changed(dev); - dev->config_change_pending = false; spin_unlock_irq(&dev->config_lock); } diff --git a/include/linux/virtio.h b/include/linux/virtio.h index 98db6390c1be..11b2bfcf6a2f 100644 --- a/include/linux/virtio.h +++ b/include/linux/virtio.h @@ -116,6 +116,8 @@ struct virtio_admin_cmd { * @index: unique position on the virtio bus * @failed: saved value for VIRTIO_CONFIG_S_FAILED bit (for restore) * @config_core_enabled: configuration change reporting enabled by core + * @config_driver_disabled: configuration change reporting disabled by + * a driver * @config_change_pending: configuration change reported while disabled * @config_lock: protects configuration change reporting * @vqs_list_lock: protects @vqs. @@ -133,6 +135,7 @@ struct virtio_device { int index; bool failed; bool config_core_enabled; + bool config_driver_disabled; bool config_change_pending; spinlock_t config_lock; spinlock_t vqs_list_lock; @@ -163,6 +166,10 @@ void __virtqueue_break(struct virtqueue *_vq); void __virtqueue_unbreak(struct virtqueue *_vq); void virtio_config_changed(struct virtio_device *dev); + +void virtio_config_driver_disable(struct virtio_device *dev); +void virtio_config_driver_enable(struct virtio_device *dev); + #ifdef CONFIG_PM_SLEEP int virtio_device_freeze(struct virtio_device *dev); int virtio_device_restore(struct virtio_device *dev);