similar to: [RFC PATCH 0/8] virtio: new API for addition of buffers, scatterlist changes

Most device drivers do not need to perform any postprocessing on the scatterlists they receive from higher-level drivers (e.g. the block or SCSI layer), because they translate the request metadata directly from the various C structs into the data that is required by the device. virtio devices however do this translation in two steps: a device-specific step in the device driver, and generic

Most device drivers do not need to perform any postprocessing on the scatterlists they receive from higher-level drivers (e.g. the block or SCSI layer), because they translate the request metadata directly from the various C structs into the data that is required by the device. virtio devices however do this translation in two steps: a device-specific step in the device driver, and generic

Hi all, this series adds multiqueue support to the virtio-scsi driver, based on Jason Wang's work on virtio-net. It uses a simple queue steering algorithm that expects one queue per CPU. LUNs in the same target always use the same queue (so that commands are not reordered); queue switching occurs when the request being queued is the only one for the target. Also based on Jason's

Hi all, this series adds multiqueue support to the virtio-scsi driver, based on Jason Wang's work on virtio-net. It uses a simple queue steering algorithm that expects one queue per CPU. LUNs in the same target always use the same queue (so that commands are not reordered); queue switching occurs when the request being queued is the only one for the target. Also based on Jason's

OK, this is (ab)uses some of Paolo's patches. The first 7 are candidates for this merge window (maybe), the rest I'm not so sure about. Thanks, Rusty. Paolo Bonzini (3): scatterlist: introduce sg_unmark_end virtio-blk: reorganize virtblk_add_req virtio-blk: use virtqueue_add_sgs on req path Rusty Russell (13): virtio_ring: virtqueue_add_sgs, to add multiple sgs. virtio-blk:

OK, this is (ab)uses some of Paolo's patches. The first 7 are candidates for this merge window (maybe), the rest I'm not so sure about. Thanks, Rusty. Paolo Bonzini (3): scatterlist: introduce sg_unmark_end virtio-blk: reorganize virtblk_add_req virtio-blk: use virtqueue_add_sgs on req path Rusty Russell (13): virtio_ring: virtqueue_add_sgs, to add multiple sgs. virtio-blk:

Add virtqueue_add_sgs which is more general than virtqueue_add_buf, which makes virtio-scsi and virtio-blk nicer, then add virtqueue_add_inbuf and virtqueue_add_outbuf which handle the more general case, and finally delete virtqueue_add_buf(). I'm hoping this will be the final post of the whole series, and it can move from my pending-rebases tree into virtio-next. Thanks! Rusty. Paolo

Add virtqueue_add_sgs which is more general than virtqueue_add_buf, which makes virtio-scsi and virtio-blk nicer, then add virtqueue_add_inbuf and virtqueue_add_outbuf which handle the more general case, and finally delete virtqueue_add_buf(). I'm hoping this will be the final post of the whole series, and it can move from my pending-rebases tree into virtio-next. Thanks! Rusty. Paolo

Hi, all This version reworked on REQ_FLUSH and REQ_FUA support as suggested by Christoph and dropped the block core bits since Jens has picked them up. Fio test shows bio-based IO path gives the following performance improvement: 1) Ramdisk device With bio-based IO path, sequential read/write, random read/write IOPS boost : 28%, 24%, 21%, 16% Latency improvement: 32%,

Hi, all This version reworked on REQ_FLUSH and REQ_FUA support as suggested by Christoph and dropped the block core bits since Jens has picked them up. Fio test shows bio-based IO path gives the following performance improvement: 1) Ramdisk device With bio-based IO path, sequential read/write, random read/write IOPS boost : 28%, 24%, 21%, 16% Latency improvement: 32%,

Hi, all Changes in v7: - Using vbr->flags to trace request type - Dropped unnecessary struct virtio_blk *vblk parameter - Reuse struct virtblk_req in bio done function - Added performance data on normal SATA device and the reason why make it optional Fio test shows bio-based IO path gives the following performance improvement: 1) Ramdisk device With bio-based IO path, sequential

Hi, all Changes in v7: - Using vbr->flags to trace request type - Dropped unnecessary struct virtio_blk *vblk parameter - Reuse struct virtblk_req in bio done function - Added performance data on normal SATA device and the reason why make it optional Fio test shows bio-based IO path gives the following performance improvement: 1) Ramdisk device With bio-based IO path, sequential

Hi folks, This version added REQ_FLUSH and REQ_FUA support as suggested by Christoph and rebased against latest linus's tree. Jens, could you please consider picking up the dependencies 1/4 and 2/4 in your tree. Thanks! This patchset implements bio-based IO path for virito-blk to improve performance. Fio test shows bio-based IO path gives the following performance improvement: 1) Ramdisk

Hi folks, This version added REQ_FLUSH and REQ_FUA support as suggested by Christoph and rebased against latest linus's tree. Jens, could you please consider picking up the dependencies 1/4 and 2/4 in your tree. Thanks! This patchset implements bio-based IO path for virito-blk to improve performance. Fio test shows bio-based IO path gives the following performance improvement: 1) Ramdisk

Since the need for a special flag to support SCSI passthrough on a block device was added in May 2017 the SCSI passthrough support in virtio-blk has been disabled. It has always been a bad idea (just ask the original author..) and we have virtio-scsi for proper passthrough. The feature also never made it into the virtio 1.0 or later specifications. Signed-off-by: Christoph Hellwig <hch at

This patchset implements bio-based IO path for virito-blk to improve performance. Fio test shows it gives, 28%, 24%, 21%, 16% IOPS boost and 32%, 17%, 21%, 16% latency improvement for sequential read/write, random read/write respectively. Asias He (3): block: Introduce __blk_segment_map_sg() helper block: Add blk_bio_map_sg() helper virtio-blk: Add bio-based IO path for virtio-blk

This patchset implements bio-based IO path for virito-blk to improve performance. Fio test shows it gives, 28%, 24%, 21%, 16% IOPS boost and 32%, 17%, 21%, 16% latency improvement for sequential read/write, random read/write respectively. Asias He (3): block: Introduce __blk_segment_map_sg() helper block: Add blk_bio_map_sg() helper virtio-blk: Add bio-based IO path for virtio-blk

Hi, Jens & Rusty This version is rebased against linux-next which resolves the conflict with Paolo Bonzini's 'virtio-blk: allow toggling host cache between writeback and writethrough' patch. Patch 1/3 and 2/3 applies on linus's master as well. Since Rusty will pick up patch 3/3 so the changes to block core (adding blk_bio_map_sg()) will have a user. Jens, could you please

Hi, Jens & Rusty This version is rebased against linux-next which resolves the conflict with Paolo Bonzini's 'virtio-blk: allow toggling host cache between writeback and writethrough' patch. Patch 1/3 and 2/3 applies on linus's master as well. Since Rusty will pick up patch 3/3 so the changes to block core (adding blk_bio_map_sg()) will have a user. Jens, could you please

This patchset implements bio-based IO path for virito-blk to improve performance. Fio test shows it gives, 28%, 24%, 21%, 16% IOPS boost and 32%, 17%, 21%, 16% latency improvement for sequential read/write, random read/write respectively. Asias He (2): block: Add blk_bio_map_sg() helper virtio-blk: Add bio-based IO path for virtio-blk block/blk-merge.c | 63 ++++++++++++++