Jason Wang
2023-Mar-24 06:47 UTC
[PATCH vhost v5 05/11] virtio_ring: packed: support premapped
On Fri, Mar 24, 2023 at 2:30?PM Xuan Zhuo <xuanzhuo at linux.alibaba.com> wrote:> > virtio core only supports virtual addresses, dma is completed in virtio > core. > > In some scenarios (such as the AF_XDP), the memory is allocated > and DMA mapping is completed in advance, so it is necessary for us to > support passing the DMA address to virtio core. > > Drives can use sg->dma_address to pass the mapped dma address to virtio > core. If one sg->dma_address is used then all sgs must use > sg->dma_address, otherwise all must be null when passing it to the APIs > of virtio. > > Signed-off-by: Xuan Zhuo <xuanzhuo at linux.alibaba.com> > --- > drivers/virtio/virtio_ring.c | 17 ++++++++++++++--- > 1 file changed, 14 insertions(+), 3 deletions(-) > > diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c > index 1c3084a8f4e3..df6d514a681a 100644 > --- a/drivers/virtio/virtio_ring.c > +++ b/drivers/virtio/virtio_ring.c > @@ -78,6 +78,7 @@ struct vring_desc_state_split { > struct vring_desc_state_packed { > void *data; /* Data for callback. */ > struct vring_packed_desc *indir_desc; /* Indirect descriptor, if any. */ > + u64 flags; /* State flags. */I'd use u32 then there would be no need for the compiler to pad the structure in both 32 and 64 bit archs. Thanks
Xuan Zhuo
2023-Mar-24 06:55 UTC
[PATCH vhost v5 05/11] virtio_ring: packed: support premapped
On Fri, 24 Mar 2023 14:47:56 +0800, Jason Wang <jasowang at redhat.com> wrote:> On Fri, Mar 24, 2023 at 2:30?PM Xuan Zhuo <xuanzhuo at linux.alibaba.com> wrote: > > > > virtio core only supports virtual addresses, dma is completed in virtio > > core. > > > > In some scenarios (such as the AF_XDP), the memory is allocated > > and DMA mapping is completed in advance, so it is necessary for us to > > support passing the DMA address to virtio core. > > > > Drives can use sg->dma_address to pass the mapped dma address to virtio > > core. If one sg->dma_address is used then all sgs must use > > sg->dma_address, otherwise all must be null when passing it to the APIs > > of virtio. > > > > Signed-off-by: Xuan Zhuo <xuanzhuo at linux.alibaba.com> > > --- > > drivers/virtio/virtio_ring.c | 17 ++++++++++++++--- > > 1 file changed, 14 insertions(+), 3 deletions(-) > > > > diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c > > index 1c3084a8f4e3..df6d514a681a 100644 > > --- a/drivers/virtio/virtio_ring.c > > +++ b/drivers/virtio/virtio_ring.c > > @@ -78,6 +78,7 @@ struct vring_desc_state_split { > > struct vring_desc_state_packed { > > void *data; /* Data for callback. */ > > struct vring_packed_desc *indir_desc; /* Indirect descriptor, if any. */ > > + u64 flags; /* State flags. */ > > I'd use u32 then there would be no need for the compiler to pad the > structure in both 32 and 64 bit archs.OK. I just try to keep the same as split. Maybe I should add some notes, indicating that there is some difference between split. Thanks.> > Thanks >