On Thu, 17 Feb 2022 15:19:44 +0800, Jason Wang <jasowang@xxxxxxxxxx> wrote: > On Thu, Feb 10, 2022 at 4:51 PM Xuan Zhuo <xuanzhuo@xxxxxxxxxxxxxxxxx> wrote: > > > > virtqueue_add() only supports virtual addresses, dma is completed in > > virtqueue_add(). > > > > In some scenarios (such as the AF_XDP scenario), DMA is completed in advance, so > > it is necessary for us to support passing the DMA address to virtqueue_add(). > > I'd suggest rename this feature as "unmanaged DMA". OK > > > > > Record this predma information in extra->flags, which can be skipped when > > executing dma unmap. > > Question still, can we use per-virtqueue flag instead of per > descriptor flag? If my memory is correct, the answer is yes in the > discussion for the previous version. > Yes. per-virtqueue? I guess it should be per-submit. This patch set only adds a flag to desc_extra[head].flags, so that we can know if we need to unmap dma when we detach. Thanks. > Thanks > > > > > v1: > > 1. All sgs requested at one time are required to be unified PREDMA, and several > > of them are not supported to be PREDMA > > 2. virtio_dma_map() is removed from this patch set and will be submitted > > together with the next time AF_XDP supports virtio dma > > 3. Added patch #2 #3 to remove the check for flags when performing unmap > > indirect desc > > > > Xuan Zhuo (6): > > virtio: rename vring_unmap_state_packed() to > > vring_unmap_extra_packed() > > virtio: remove flags check for unmap split indirect desc > > virtio: remove flags check for unmap packed indirect desc > > virtio: virtqueue_add() support predma > > virtio: split: virtqueue_add_split() support dma address > > virtio: packed: virtqueue_add_packed() support dma address > > > > drivers/virtio/virtio_ring.c | 199 ++++++++++++++++++++++------------- > > 1 file changed, 126 insertions(+), 73 deletions(-) > > > > -- > > 2.31.0 > > > _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/virtualization
