As discussed: http://lore.kernel.org/all/CACGkMEvq0No8QGC46U4mGsMtuD44fD_cfLcPaVmJ3rHYqRZxYg@xxxxxxxxxxxxxx If the virtio is premapped mode, the driver should manage the dma info by self. So the virtio core should not store the dma info. So we can release the memory used to store the dma info. But if the desc_extra has not dma info, we face a new question, it is hard to get the dma info of the desc with indirect flag. For split mode, that is easy from desc, but for the packed mode, it is hard to get the dma info from the desc. And for hardening the dma unmap is saft, we should store the dma info of indirect descs. So I introduce the "structure the indirect desc table" to allocate space to store dma info with the desc table. On the other side, we mix the descs with indirect flag with other descs together to share the unmap api. That is complex. I found if we we distinguish the descs with VRING_DESC_F_INDIRECT before unmap, thing will be clearer. Because of the dma array is allocated in the find_vqs(), so I introduce a new parameter to find_vqs(). Please review. Thanks Xuan Zhuo (17): virtio_ring: introduce vring_need_unmap_buffer virtio_ring: packed: remove double check of the unmap ops virtio_ring: packed: structure the indirect desc table virtio_ring: split: remove double check of the unmap ops virtio_ring: split: structure the indirect desc table virtio_ring: no store dma info when unmap is not needed virtio: find_vqs: pass struct instead of multi parameters virtio: vring_new_virtqueue(): pass struct instead of multi parameters virtio_ring: reuse the parameter struct of find_vqs() virtio: find_vqs: add new parameter premapped virtio_ring: export premapped to driver by struct virtqueue virtio_net: set premapped mode by find_vqs() virtio_ring: remove api of setting vq premapped virtio_ring: introduce dma map api for page virtio_net: unify the code for recycling the xmit ptr virtio_net: rename free_old_xmit_skbs to free_old_xmit virtio_net: sq support premapped mode arch/um/drivers/virtio_uml.c | 29 +- drivers/net/virtio_net.c | 298 +++++++--- drivers/platform/mellanox/mlxbf-tmfifo.c | 24 +- drivers/remoteproc/remoteproc_virtio.c | 31 +- drivers/s390/virtio/virtio_ccw.c | 33 +- drivers/virtio/virtio_mmio.c | 30 +- drivers/virtio/virtio_pci_common.c | 59 +- drivers/virtio/virtio_pci_common.h | 9 +- drivers/virtio/virtio_pci_legacy.c | 16 +- drivers/virtio/virtio_pci_modern.c | 24 +- drivers/virtio/virtio_ring.c | 660 ++++++++++++----------- drivers/virtio/virtio_vdpa.c | 33 +- include/linux/virtio.h | 10 +- include/linux/virtio_config.h | 48 +- include/linux/virtio_ring.h | 82 +-- tools/virtio/virtio_test.c | 4 +- tools/virtio/vringh_test.c | 32 +- 17 files changed, 812 insertions(+), 610 deletions(-) -- 2.32.0.3.g01195cf9f
