Avoid emulating FUA when the driver supports it natively. This should provide better performance than a full flush after the write.
Signed-off-by: Alberto Faria <afa...@redhat.com> --- hw/scsi/scsi-disk.c | 17 +++++++++++------ 1 file changed, 11 insertions(+), 6 deletions(-) diff --git a/hw/scsi/scsi-disk.c b/hw/scsi/scsi-disk.c index 8cf50845ab..ce48e20ee6 100644 --- a/hw/scsi/scsi-disk.c +++ b/hw/scsi/scsi-disk.c @@ -43,6 +43,7 @@ #include "qemu/cutils.h" #include "trace.h" #include "qom/object.h" +#include "block/block_int-common.h" #ifdef __linux #include <scsi/sg.h> @@ -75,7 +76,7 @@ struct SCSIDiskClass { */ DMAIOFunc *dma_readv; DMAIOFunc *dma_writev; - bool (*need_fua_emulation)(SCSICommand *cmd); + bool (*need_fua)(SCSICommand *cmd); void (*update_sense)(SCSIRequest *r); }; @@ -86,6 +87,7 @@ typedef struct SCSIDiskReq { uint32_t sector_count; uint32_t buflen; bool started; + bool need_fua; bool need_fua_emulation; struct iovec iov; QEMUIOVector qiov; @@ -553,7 +555,7 @@ static void scsi_read_data(SCSIRequest *req) first = !r->started; r->started = true; - if (first && r->need_fua_emulation) { + if (first && r->need_fua) { block_acct_start(blk_get_stats(s->qdev.conf.blk), &r->acct, 0, BLOCK_ACCT_FLUSH); r->req.aiocb = blk_aio_flush(s->qdev.conf.blk, scsi_do_read_cb, r); @@ -2384,7 +2386,9 @@ static int32_t scsi_disk_dma_command(SCSIRequest *req, uint8_t *buf) scsi_check_condition(r, SENSE_CODE(LBA_OUT_OF_RANGE)); return 0; } - r->need_fua_emulation = sdc->need_fua_emulation(&r->req.cmd); + r->need_fua = sdc->need_fua(&r->req.cmd); + r->need_fua_emulation = r->need_fua && + (blk_bs(s->qdev.conf.blk)->supported_write_flags & BDRV_REQ_FUA) == 0; if (r->sector_count == 0) { scsi_req_complete(&r->req, GOOD); } @@ -3134,7 +3138,8 @@ BlockAIOCB *scsi_dma_writev(int64_t offset, QEMUIOVector *iov, { SCSIDiskReq *r = opaque; SCSIDiskState *s = DO_UPCAST(SCSIDiskState, qdev, r->req.dev); - return blk_aio_pwritev(s->qdev.conf.blk, offset, iov, 0, cb, cb_opaque); + int flags = r->need_fua && !r->need_fua_emulation ? BDRV_REQ_FUA : 0; + return blk_aio_pwritev(s->qdev.conf.blk, offset, iov, flags, cb, cb_opaque); } static char *scsi_property_get_loadparm(Object *obj, Error **errp) @@ -3183,7 +3188,7 @@ static void scsi_disk_base_class_initfn(ObjectClass *klass, void *data) device_class_set_legacy_reset(dc, scsi_disk_reset); sdc->dma_readv = scsi_dma_readv; sdc->dma_writev = scsi_dma_writev; - sdc->need_fua_emulation = scsi_is_cmd_fua; + sdc->need_fua = scsi_is_cmd_fua; } static const TypeInfo scsi_disk_base_info = { @@ -3335,7 +3340,7 @@ static void scsi_block_class_initfn(ObjectClass *klass, void *data) sdc->dma_readv = scsi_block_dma_readv; sdc->dma_writev = scsi_block_dma_writev; sdc->update_sense = scsi_block_update_sense; - sdc->need_fua_emulation = scsi_block_no_fua; + sdc->need_fua = scsi_block_no_fua; dc->desc = "SCSI block device passthrough"; device_class_set_props(dc, scsi_block_properties); dc->vmsd = &vmstate_scsi_disk_state; -- 2.48.1