From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: virtio-dev-return-5347-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 01365985E58 for ; Wed, 23 Jan 2019 08:04:52 +0000 (UTC) Date: Wed, 23 Jan 2019 16:02:27 +0800 From: Tiwei Bie Message-ID: <20190123080227.GA23394@dpdk-tbie> References: <20190122170346.6279-1-tiwei.bie@intel.com> <20190122230247-mutt-send-email-mst@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20190122230247-mutt-send-email-mst@kernel.org> Subject: [virtio-dev] Re: [PATCH] virtio: support VIRTIO_F_ORDER_PLATFORM To: "Michael S. Tsirkin" Cc: jasowang@redhat.com, virtualization@lists.linux-foundation.org, linux-kernel@vger.kernel.org, virtio-dev@lists.oasis-open.org List-ID: On Tue, Jan 22, 2019 at 11:04:29PM -0500, Michael S. Tsirkin wrote: > On Wed, Jan 23, 2019 at 01:03:46AM +0800, Tiwei Bie wrote: > > This patch introduces the support for VIRTIO_F_ORDER_PLATFORM. > > When this feature is negotiated, driver will use the barriers > > suitable for hardware devices. > > > > Signed-off-by: Tiwei Bie > > Could you pls add a bit more explanation in the commit log? > E.g. which configurations are broken without this patch? > How severe is the problem? Sure. Will do that. Thanks > > I'm trying to decide whether this belongs in 5.0 or 5.1. > > > --- > > drivers/virtio/virtio_ring.c | 8 ++++++++ > > include/uapi/linux/virtio_config.h | 6 ++++++ > > 2 files changed, 14 insertions(+) > > > > diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c > > index cd7e755484e3..27d3f057493e 100644 > > --- a/drivers/virtio/virtio_ring.c > > +++ b/drivers/virtio/virtio_ring.c > > @@ -1609,6 +1609,9 @@ static struct virtqueue *vring_create_virtqueue_packed( > > !context; > > vq->event = virtio_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX); > > > > + if (virtio_has_feature(vdev, VIRTIO_F_ORDER_PLATFORM)) > > + vq->weak_barriers = false; > > + > > vq->packed.ring_dma_addr = ring_dma_addr; > > vq->packed.driver_event_dma_addr = driver_event_dma_addr; > > vq->packed.device_event_dma_addr = device_event_dma_addr; > > @@ -2079,6 +2082,9 @@ struct virtqueue *__vring_new_virtqueue(unsigned int index, > > !context; > > vq->event = virtio_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX); > > > > + if (virtio_has_feature(vdev, VIRTIO_F_ORDER_PLATFORM)) > > + vq->weak_barriers = false; > > + > > vq->split.queue_dma_addr = 0; > > vq->split.queue_size_in_bytes = 0; > > > > @@ -2213,6 +2219,8 @@ void vring_transport_features(struct virtio_device *vdev) > > break; > > case VIRTIO_F_RING_PACKED: > > break; > > + case VIRTIO_F_ORDER_PLATFORM: > > + break; > > default: > > /* We don't understand this bit. */ > > __virtio_clear_bit(vdev, i); > > diff --git a/include/uapi/linux/virtio_config.h b/include/uapi/linux/virtio_config.h > > index 1196e1c1d4f6..ff8e7dc9d4dd 100644 > > --- a/include/uapi/linux/virtio_config.h > > +++ b/include/uapi/linux/virtio_config.h > > @@ -78,6 +78,12 @@ > > /* This feature indicates support for the packed virtqueue layout. */ > > #define VIRTIO_F_RING_PACKED 34 > > > > +/* > > + * This feature indicates that memory accesses by the driver and the > > + * device are ordered in a way described by the platform. > > + */ > > +#define VIRTIO_F_ORDER_PLATFORM 36 > > + > > /* > > * Does the device support Single Root I/O Virtualization? > > */ > > -- > > 2.17.1 --------------------------------------------------------------------- To unsubscribe, e-mail: virtio-dev-unsubscribe@lists.oasis-open.org For additional commands, e-mail: virtio-dev-help@lists.oasis-open.org