kernel/linux.git/drivers/vhost/scsi.c, branch v6.6.39

vhost-scsi: Handle vhost_vq_work_queue failures for events

2024-07-11T10:49:20+00:00

[ Upstream commit b1b2ce58ed23c5d56e0ab299a5271ac01f95b75c ] Currently, we can try to queue an event's work before the vhost_task is created. When this happens we just drop it in vhost_scsi_do_plug before even calling vhost_vq_work_queue. During a device shutdown we do the same thing after vhost_scsi_clear_endpoint has cleared the backends. In the next patches we will be able to kill the vhost_task before we have cleared the endpoint. In that case, vhost_vq_work_queue can fail and we will leak the event's memory. This has handle the failure by just freeing the event. This is safe to do, because vhost_vq_work_queue will only return failure for us when the vhost_task is killed and so userspace will not be able to handle events if we sent them. Signed-off-by: Mike Christie Message-Id: <20240316004707.45557-2-michael.christie@oracle.com> Signed-off-by: Michael S. Tsirkin Signed-off-by: Sasha Levin

vhost-scsi: Rename vhost_scsi_iov_to_sgl

2023-08-10T19:24:28+00:00

Rename vhost_scsi_iov_to_sgl to vhost_scsi_map_iov_to_sgl so it matches matches the naming style used for vhost_scsi_copy_iov_to_sgl. Signed-off-by: Mike Christie Message-Id: <20230709202859.138387-3-michael.christie@oracle.com> Signed-off-by: Michael S. Tsirkin Acked-by: Stefan Hajnoczi

vhost-scsi: Fix alignment handling with windows

2023-08-10T19:24:27+00:00

The linux block layer requires bios/requests to have lengths with a 512 byte alignment. Some drivers/layers like dm-crypt and the directi IO code will test for it and just fail. Other drivers like SCSI just assume the requirement is met and will end up in infinte retry loops. The problem for drivers like SCSI is that it uses functions like blk_rq_cur_sectors and blk_rq_sectors which divide the request's length by 512. If there's lefovers then it just gets dropped. But other code in the block/scsi layer may use blk_rq_bytes/blk_rq_cur_bytes and end up thinking there is still data left and try to retry the cmd. We can then end up getting stuck in retry loops where part of the block/scsi thinks there is data left, but other parts think we want to do IOs of zero length. Linux will always check for alignment, but windows will not. When vhost-scsi then translates the iovec it gets from a windows guest to a scatterlist, we can end up with sg items where the sg->length is not divisible by 512 due to the misaligned offset: sg[0].offset = 255; sg[0].length = 3841; sg... sg[N].offset = 0; sg[N].length = 255; When the lio backends then convert the SG to bios or other iovecs, we end up sending them with the same misaligned values and can hit the issues above. This just has us drop down to allocating a temp page and copying the data when we detect a misaligned buffer and the IO is large enough that it will get split into multiple bad IOs. Signed-off-by: Mike Christie Message-Id: <20230709202859.138387-2-michael.christie@oracle.com> Signed-off-by: Michael S. Tsirkin Acked-by: Stefan Hajnoczi

vhost_scsi: add support for worker ioctls

2023-07-03T16:15:14+00:00

This has vhost-scsi support the worker ioctls by calling the vhost_worker_ioctl helper. With a single worker, the single thread becomes a bottlneck when trying to use 3 or more virtqueues like: fio --filename=/dev/sdb --direct=1 --rw=randrw --bs=4k \ --ioengine=libaio --iodepth=128 --numjobs=3 With the patches and doing a worker per vq, we can scale to at least 16 vCPUs/vqs (that's my system limit) with the same command fio command above with numjobs=16: fio --filename=/dev/sdb --direct=1 --rw=randrw --bs=4k \ --ioengine=libaio --iodepth=64 --numjobs=16 which gives around 2002K IOPs. Note that for testing I dropped depth to 64 above because the vhost/virt layer supports only 1024 total commands per device. And the only tuning I did was set LIO's emulate_pr to 0 to avoid LIO's PR lock in the main IO path which becomes an issue at around 12 jobs/virtqueues. Signed-off-by: Mike Christie Message-Id: <20230626232307.97930-17-michael.christie@oracle.com> Signed-off-by: Michael S. Tsirkin

vhost_scsi: flush IO vqs then send TMF rsp

2023-07-03T16:15:14+00:00

With one worker we will always send the scsi cmd responses then send the TMF rsp, because LIO will always complete the scsi cmds first then call into us to send the TMF response. With multiple workers, the IO vq workers could be running while the TMF/ctl vq worker is running so this has us do a flush before completing the TMF to make sure cmds are completed when it's work is later queued and run. Signed-off-by: Mike Christie Message-Id: <20230626232307.97930-12-michael.christie@oracle.com> Signed-off-by: Michael S. Tsirkin

vhost_scsi: convert to vhost_vq_work_queue

2023-07-03T16:15:13+00:00

Convert from vhost_work_queue to vhost_vq_work_queue so we can remove vhost_work_queue. Signed-off-by: Mike Christie Message-Id: <20230626232307.97930-11-michael.christie@oracle.com> Signed-off-by: Michael S. Tsirkin

vhost_scsi: make SCSI cmd completion per vq

2023-07-03T16:15:13+00:00

This patch separates the scsi cmd completion code paths so we can complete cmds based on their vq instead of having all cmds complete on the same worker/CPU. This will be useful with the next patches that allow us to create mulitple worker threads and bind them to different vqs, and we can have completions running on different threads/CPUs. Signed-off-by: Mike Christie Reviewed-by: Stefan Hajnoczi Message-Id: <20230626232307.97930-10-michael.christie@oracle.com> Signed-off-by: Michael S. Tsirkin

Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost

2023-04-28T00:05:34+00:00

Pull virtio updates from Michael Tsirkin: "virtio,vhost,vdpa: features, fixes, and cleanups: - reduction in interrupt rate in virtio - perf improvement for VDUSE - scalability for vhost-scsi - non power of 2 ring support for packed rings - better management for mlx5 vdpa - suspend for snet - VIRTIO_F_NOTIFICATION_DATA - shared backend with vdpa-sim-blk - user VA support in vdpa-sim - better struct packing for virtio and fixes, cleanups all over the place" * tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost: (52 commits) vhost_vdpa: fix unmap process in no-batch mode MAINTAINERS: make me a reviewer of VIRTIO CORE AND NET DRIVERS tools/virtio: fix build caused by virtio_ring changes virtio_ring: add a struct device forward declaration vdpa_sim_blk: support shared backend vdpa_sim: move buffer allocation in the devices vdpa/snet: use likely/unlikely macros in hot functions vdpa/snet: implement kick_vq_with_data callback virtio-vdpa: add VIRTIO_F_NOTIFICATION_DATA feature support virtio: add VIRTIO_F_NOTIFICATION_DATA feature support vdpa/snet: support the suspend vDPA callback vdpa/snet: support getting and setting VQ state MAINTAINERS: add vringh.h to Virtio Core and Net Drivers vringh: address kdoc warnings vdpa: address kdoc warnings virtio_ring: don't update event idx on get_buf vdpa_sim: add support for user VA vdpa_sim: replace the spinlock with a mutex to protect the state vdpa_sim: use kthread worker vdpa_sim: make devices agnostic for work management ...

Merge tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi

2023-04-26T22:39:25+00:00

Pull SCSI updates from James Bottomley: "Updates to the usual drivers (megaraid_sas, scsi_debug, lpfc, target, mpi3mr, hisi_sas, arcmsr). The major core change is the constification of the host templates (which touches everything) along with other minor fixups and clean ups" * tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (207 commits) scsi: ufs: mcq: Use pointer arithmetic in ufshcd_send_command() scsi: ufs: mcq: Annotate ufshcd_inc_sq_tail() appropriately scsi: cxlflash: s/semahpore/semaphore/ scsi: lpfc: Silence an incorrect device output scsi: mpi3mr: Use IRQ save variants of spinlock to protect chain frame allocation scsi: scsi_debug: Fix missing error code in scsi_debug_init() scsi: hisi_sas: Work around build failure in suspend function scsi: lpfc: Fix ioremap issues in lpfc_sli4_pci_mem_setup() scsi: mpt3sas: Fix an issue when driver is being removed scsi: mpt3sas: Remove HBA BIOS version in the kernel log scsi: target: core: Fix invalid memory access scsi: scsi_debug: Drop sdebug_queue scsi: scsi_debug: Only allow sdebug_max_queue be modified when no shosts scsi: scsi_debug: Use scsi_host_busy() in delay_store() and ndelay_store() scsi: scsi_debug: Use blk_mq_tagset_busy_iter() in stop_all_queued() scsi: scsi_debug: Use blk_mq_tagset_busy_iter() in sdebug_blk_mq_poll() scsi: scsi_debug: Dynamically allocate sdebug_queued_cmd scsi: scsi_debug: Use scsi_block_requests() to block queues scsi: scsi_debug: Protect block_unblock_all_queues() with mutex scsi: scsi_debug: Change shost list lock to a mutex ...

Merge tag 'iter-ubuf.2-2023-04-21' of git://git.kernel.dk/linux

2023-04-24T17:29:28+00:00

Pull ITER_UBUF updates from Jens Axboe: "This turns singe vector imports into ITER_UBUF, rather than ITER_IOVEC. The former is more trivial to iterate and advance, and hence a bit more efficient. From some very unscientific testing, ~60% of all iovec imports are single vector" * tag 'iter-ubuf.2-2023-04-21' of git://git.kernel.dk/linux: iov_iter: Mark copy_compat_iovec_from_user() noinline iov_iter: import single vector iovecs as ITER_UBUF iov_iter: convert import_single_range() to ITER_UBUF iov_iter: overlay struct iovec and ubuf/len iov_iter: set nr_segs = 1 for ITER_UBUF iov_iter: remove iov_iter_iovec() iov_iter: add iter_iov_addr() and iter_iov_len() helpers ALSA: pcm: check for user backed iterator, not specific iterator type IB/qib: check for user backed iterator, not specific iterator type IB/hfi1: check for user backed iterator, not specific iterator type iov_iter: add iter_iovec() helper block: ensure bio_alloc_map_data() deals with ITER_UBUF correctly