From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: virtio-dev-return-5240-cohuck=redhat.com@lists.oasis-open.org Sender: List-Post: List-Help: List-Unsubscribe: List-Subscribe: Received: from lists.oasis-open.org (oasis-open.org [10.110.1.242]) by lists.oasis-open.org (Postfix) with ESMTP id 05F93985C35 for ; Thu, 3 Jan 2019 16:08:18 +0000 (UTC) From: Cornelia Huck Date: Thu, 3 Jan 2019 17:08:04 +0100 Message-Id: <20190103160804.21438-3-cohuck@redhat.com> In-Reply-To: <20190103160804.21438-1-cohuck@redhat.com> References: <20190103160804.21438-1-cohuck@redhat.com> Subject: [virtio-dev] [PATCH 2/2] virtio: document virtio_config_ops restrictions To: "Michael S . Tsirkin" , Jason Wang Cc: virtualization@lists.linux-foundation.org, linux-kernel@vger.kernel.org, virtio-dev@lists.oasis-open.org, Wei Wang , Halil Pasic , Cornelia Huck List-ID: Some transports (e.g. virtio-ccw) implement virtio operations that seem to be a simple read/write as something more involved that cannot be done from an atomic context. Give at least a hint about that. Signed-off-by: Cornelia Huck --- include/linux/virtio_config.h | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/include/linux/virtio_config.h b/include/linux/virtio_config.h index 7087ef946ba7..987b6491b946 100644 --- a/include/linux/virtio_config.h +++ b/include/linux/virtio_config.h @@ -12,6 +12,11 @@ struct irq_affinity; /** * virtio_config_ops - operations for configuring a virtio device + * Note: Do not assume that a transport implements all of the operations + * getting/setting a value as a simple read/write! Generally speaking, + * any of @get/@set, @get_status/@set_status, or @get_features/ + * @finalize_features are NOT safe to be called from an atomic + * context. * @get: read the value of a configuration field * vdev: the virtio_device * offset: the offset of the configuration field -- 2.17.2 --------------------------------------------------------------------- To unsubscribe, e-mail: virtio-dev-unsubscribe@lists.oasis-open.org For additional commands, e-mail: virtio-dev-help@lists.oasis-open.org