On Thu, Feb 10, 2022 at 4:51 PM Xuan Zhuo <[email protected]> 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". > > 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. 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 [email protected] https://lists.linuxfoundation.org/mailman/listinfo/virtualization
