Xuan Zhuo
2023-Jul-10 03:42 UTC
[PATCH vhost v11 05/10] virtio_ring: introduce virtqueue_dma_dev()
Added virtqueue_dma_dev() to get DMA device for virtio. Then the
caller can do dma operation in advance. The purpose is to keep memory
mapped across multiple add/get buf operations.
Signed-off-by: Xuan Zhuo <xuanzhuo at linux.alibaba.com>
---
drivers/virtio/virtio_ring.c | 17 +++++++++++++++++
include/linux/virtio.h | 2 ++
2 files changed, 19 insertions(+)
diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index d471dee3f4f7..1fb2c6dca9ea 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -2265,6 +2265,23 @@ int virtqueue_add_inbuf_ctx(struct virtqueue *vq,
}
EXPORT_SYMBOL_GPL(virtqueue_add_inbuf_ctx);
+/**
+ * virtqueue_dma_dev - get the dma dev
+ * @_vq: the struct virtqueue we're talking about.
+ *
+ * Returns the dma dev. That can been used for dma api.
+ */
+struct device *virtqueue_dma_dev(struct virtqueue *_vq)
+{
+ struct vring_virtqueue *vq = to_vvq(_vq);
+
+ if (vq->use_dma_api)
+ return vring_dma_dev(vq);
+ else
+ return NULL;
+}
+EXPORT_SYMBOL_GPL(virtqueue_dma_dev);
+
/**
* virtqueue_kick_prepare - first half of split virtqueue_kick call.
* @_vq: the struct virtqueue
diff --git a/include/linux/virtio.h b/include/linux/virtio.h
index 2efd07b79ecf..35d175121cc6 100644
--- a/include/linux/virtio.h
+++ b/include/linux/virtio.h
@@ -61,6 +61,8 @@ int virtqueue_add_sgs(struct virtqueue *vq,
void *data,
gfp_t gfp);
+struct device *virtqueue_dma_dev(struct virtqueue *vq);
+
bool virtqueue_kick(struct virtqueue *vq);
bool virtqueue_kick_prepare(struct virtqueue *vq);
--
2.32.0.3.g01195cf9f
Jason Wang
2023-Jul-12 08:33 UTC
[PATCH vhost v11 05/10] virtio_ring: introduce virtqueue_dma_dev()
On Mon, Jul 10, 2023 at 11:42?AM Xuan Zhuo <xuanzhuo at linux.alibaba.com> wrote:> > Added virtqueue_dma_dev() to get DMA device for virtio. Then the > caller can do dma operation in advance. The purpose is to keep memory > mapped across multiple add/get buf operations. > > Signed-off-by: Xuan Zhuo <xuanzhuo at linux.alibaba.com>Acked-by: Jason Wang <jasowang at redhat.com> Thanks> --- > drivers/virtio/virtio_ring.c | 17 +++++++++++++++++ > include/linux/virtio.h | 2 ++ > 2 files changed, 19 insertions(+) > > diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c > index d471dee3f4f7..1fb2c6dca9ea 100644 > --- a/drivers/virtio/virtio_ring.c > +++ b/drivers/virtio/virtio_ring.c > @@ -2265,6 +2265,23 @@ int virtqueue_add_inbuf_ctx(struct virtqueue *vq, > } > EXPORT_SYMBOL_GPL(virtqueue_add_inbuf_ctx); > > +/** > + * virtqueue_dma_dev - get the dma dev > + * @_vq: the struct virtqueue we're talking about. > + * > + * Returns the dma dev. That can been used for dma api. > + */ > +struct device *virtqueue_dma_dev(struct virtqueue *_vq) > +{ > + struct vring_virtqueue *vq = to_vvq(_vq); > + > + if (vq->use_dma_api) > + return vring_dma_dev(vq); > + else > + return NULL; > +} > +EXPORT_SYMBOL_GPL(virtqueue_dma_dev); > + > /** > * virtqueue_kick_prepare - first half of split virtqueue_kick call. > * @_vq: the struct virtqueue > diff --git a/include/linux/virtio.h b/include/linux/virtio.h > index 2efd07b79ecf..35d175121cc6 100644 > --- a/include/linux/virtio.h > +++ b/include/linux/virtio.h > @@ -61,6 +61,8 @@ int virtqueue_add_sgs(struct virtqueue *vq, > void *data, > gfp_t gfp); > > +struct device *virtqueue_dma_dev(struct virtqueue *vq); > + > bool virtqueue_kick(struct virtqueue *vq); > > bool virtqueue_kick_prepare(struct virtqueue *vq); > -- > 2.32.0.3.g01195cf9f >
Christoph Hellwig
2023-Jul-13 11:15 UTC
[PATCH vhost v11 05/10] virtio_ring: introduce virtqueue_dma_dev()
On Mon, Jul 10, 2023 at 11:42:32AM +0800, Xuan Zhuo wrote:> Added virtqueue_dma_dev() to get DMA device for virtio. Then the > caller can do dma operation in advance. The purpose is to keep memory > mapped across multiple add/get buf operations.This is just poking holes into the abstraction..