Register guest RAM using BlockRAMRegistrar and set the BDRV_REQ_REGISTERED_BUF flag so block drivers can optimize memory accesses in I/O requests.
This is for vdpa-blk, vhost-user-blk, and other I/O interfaces that rely on DMA mapping/unmapping. Signed-off-by: Stefan Hajnoczi <stefa...@redhat.com> --- include/hw/virtio/virtio-blk.h | 2 ++ hw/block/virtio-blk.c | 13 +++++++++---- 2 files changed, 11 insertions(+), 4 deletions(-) diff --git a/include/hw/virtio/virtio-blk.h b/include/hw/virtio/virtio-blk.h index d311c57cca..7f589b4146 100644 --- a/include/hw/virtio/virtio-blk.h +++ b/include/hw/virtio/virtio-blk.h @@ -19,6 +19,7 @@ #include "hw/block/block.h" #include "sysemu/iothread.h" #include "sysemu/block-backend.h" +#include "sysemu/block-ram-registrar.h" #include "qom/object.h" #define TYPE_VIRTIO_BLK "virtio-blk-device" @@ -64,6 +65,7 @@ struct VirtIOBlock { struct VirtIOBlockDataPlane *dataplane; uint64_t host_features; size_t config_size; + BlockRAMRegistrar blk_ram_registrar; }; typedef struct VirtIOBlockReq { diff --git a/hw/block/virtio-blk.c b/hw/block/virtio-blk.c index 540c38f829..a18cf05f14 100644 --- a/hw/block/virtio-blk.c +++ b/hw/block/virtio-blk.c @@ -21,6 +21,7 @@ #include "hw/block/block.h" #include "hw/qdev-properties.h" #include "sysemu/blockdev.h" +#include "sysemu/block-ram-registrar.h" #include "sysemu/sysemu.h" #include "sysemu/runstate.h" #include "hw/virtio/virtio-blk.h" @@ -421,11 +422,13 @@ static inline void submit_requests(BlockBackend *blk, MultiReqBuffer *mrb, } if (is_write) { - blk_aio_pwritev(blk, sector_num << BDRV_SECTOR_BITS, qiov, 0, - virtio_blk_rw_complete, mrb->reqs[start]); + blk_aio_pwritev(blk, sector_num << BDRV_SECTOR_BITS, qiov, + BDRV_REQ_REGISTERED_BUF, virtio_blk_rw_complete, + mrb->reqs[start]); } else { - blk_aio_preadv(blk, sector_num << BDRV_SECTOR_BITS, qiov, 0, - virtio_blk_rw_complete, mrb->reqs[start]); + blk_aio_preadv(blk, sector_num << BDRV_SECTOR_BITS, qiov, + BDRV_REQ_REGISTERED_BUF, virtio_blk_rw_complete, + mrb->reqs[start]); } } @@ -1228,6 +1231,7 @@ static void virtio_blk_device_realize(DeviceState *dev, Error **errp) } s->change = qemu_add_vm_change_state_handler(virtio_blk_dma_restart_cb, s); + blk_ram_registrar_init(&s->blk_ram_registrar, s->blk); blk_set_dev_ops(s->blk, &virtio_block_ops, s); blk_set_guest_block_size(s->blk, s->conf.conf.logical_block_size); @@ -1255,6 +1259,7 @@ static void virtio_blk_device_unrealize(DeviceState *dev) } qemu_coroutine_decrease_pool_batch_size(conf->num_queues * conf->queue_size / 2); + blk_ram_registrar_destroy(&s->blk_ram_registrar); qemu_del_vm_change_state_handler(s->change); blockdev_mark_auto_del(s->blk); virtio_cleanup(vdev); -- 2.35.1