From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: virtio-dev-return-5328-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 14E2B9849F6 for ; Tue, 15 Jan 2019 02:12:37 +0000 (UTC) Message-ID: <5C3D42E1.7030005@intel.com> Date: Tue, 15 Jan 2019 10:18:09 +0800 From: Wei Wang MIME-Version: 1.0 References: <20190103160804.21438-1-cohuck@redhat.com> <20190103160804.21438-3-cohuck@redhat.com> In-Reply-To: <20190103160804.21438-3-cohuck@redhat.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [virtio-dev] [PATCH 2/2] virtio: document virtio_config_ops restrictions To: Cornelia Huck , "Michael S . Tsirkin" , Jason Wang Cc: virtualization@lists.linux-foundation.org, linux-kernel@vger.kernel.org, virtio-dev@lists.oasis-open.org, Halil Pasic List-ID: On 01/04/2019 12:08 AM, Cornelia Huck wrote: > 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 Reviewed-by: Wei Wang Best, Wei --------------------------------------------------------------------- To unsubscribe, e-mail: virtio-dev-unsubscribe@lists.oasis-open.org For additional commands, e-mail: virtio-dev-help@lists.oasis-open.org