On Thu, Feb 29, 2024 at 03:20:25PM +0800, Xuan Zhuo wrote: > 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(). > > Note: > this is on the top of > [PATCH vhost v1] virtio: packed: fix unmap leak for indirect desc table > http://lore.kernel.org/all/20240223071833.26095-1-xuanzhuo@xxxxxxxxxxxxxxxxx > > Please review. > > Thanks > > v3: > 1. fix the conflict with the vp_modern_create_avq(). Okay but are you going to address huge memory waste all this is causing for - people who never do zero copy - systems where dma unmap is a nop ? You should address all comments when you post a new version, not just what was expedient, or alternatively tag patch as RFC and explain in commit log that you plan to do it later. > v2: > 1. change the dma item of virtio-net, every item have MAX_SKB_FRAGS + 2 > addr + len pairs. > 2. introduce virtnet_sq_free_stats for __free_old_xmit > > v1: > 1. rename transport_vq_config to vq_transport_config > 2. virtio-net set dma meta number to (ring-size + 1)(MAX_SKB_FRGAS +2) > 3. introduce virtqueue_dma_map_sg_attrs > 4. separate vring_create_virtqueue to an independent commit > > > > Xuan Zhuo (19): > 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_create_virtqueue: pass struct instead of multi > parameters > virtio: vring_new_virtqueue(): pass struct instead of multi parameters > virtio_ring: simplify the parameters of the funcs related to > vring_create/new_virtqueue() > 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_ring: introduce virtqueue_dma_map_sg_attrs > 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 | 31 +- > drivers/net/virtio_net.c | 283 ++++++--- > 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 | 38 +- > drivers/virtio/virtio_ring.c | 698 ++++++++++++----------- > drivers/virtio/virtio_vdpa.c | 45 +- > include/linux/virtio.h | 13 +- > include/linux/virtio_config.h | 48 +- > include/linux/virtio_ring.h | 82 +-- > tools/virtio/virtio_test.c | 4 +- > tools/virtio/vringh_test.c | 28 +- > 17 files changed, 847 insertions(+), 625 deletions(-) > > -- > 2.32.0.3.g01195cf9f
