On Mon, 05/23 14:54, Paolo Bonzini wrote:
> scsi-block will be able to do FUA just by passing the request through
> to the LUN (which is also more efficient); there is no need to emulate
> it like we do for scsi-disk.
Even for scsi-disk, shall we just use the block layer FUA fallback already by
passing BDRV_REQ_FUA in blk_aio_pwritev and simply the code in this series?
>
> Add a new method to distinguish this.
>
> Signed-off-by: Paolo Bonzini <pbonz...@redhat.com>
> ---
> hw/scsi/scsi-disk.c | 9 +++++++--
> 1 file changed, 7 insertions(+), 2 deletions(-)
>
> diff --git a/hw/scsi/scsi-disk.c b/hw/scsi/scsi-disk.c
> index 4b5db59..f9870e9 100644
> --- a/hw/scsi/scsi-disk.c
> +++ b/hw/scsi/scsi-disk.c
> @@ -69,6 +69,7 @@ typedef struct SCSIDiskClass {
> SCSIDeviceClass parent_class;
> DMAIOFunc *dma_readv;
> DMAIOFunc *dma_writev;
> + bool (*need_fua_emulation)(SCSICommand *cmd);
> } SCSIDiskClass;
>
> typedef struct SCSIDiskReq {
> @@ -78,6 +79,7 @@ typedef struct SCSIDiskReq {
> uint32_t sector_count;
> uint32_t buflen;
> bool started;
> + bool need_fua_emulation;
> struct iovec iov;
> QEMUIOVector qiov;
> BlockAcctCookie acct;
> @@ -239,7 +241,7 @@ static void scsi_write_do_fua(SCSIDiskReq *r)
> goto done;
> }
>
> - if (scsi_is_cmd_fua(&r->req.cmd)) {
> + if (r->need_fua_emulation) {
Should this evaluate a call to r->need_fua_emulation() instead of the function
pointer itself?
> 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_aio_complete, r);
> @@ -416,7 +418,7 @@ static void scsi_read_data(SCSIRequest *req)
>
> first = !r->started;
> r->started = true;
> - if (first && scsi_is_cmd_fua(&r->req.cmd)) {
> + if (first && r->need_fua_emulation) {
> 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);
> @@ -2157,6 +2159,7 @@ static int32_t scsi_disk_dma_command(SCSIRequest *req,
> uint8_t *buf)
> {
> SCSIDiskReq *r = DO_UPCAST(SCSIDiskReq, req, req);
> SCSIDiskState *s = DO_UPCAST(SCSIDiskState, qdev, req->dev);
> + SCSIDiskClass *sdc = (SCSIDiskClass *) object_get_class(OBJECT(s));
> uint32_t len;
> uint8_t command;
>
> @@ -2215,6 +2218,7 @@ 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);
> if (r->sector_count == 0) {
> scsi_req_complete(&r->req, GOOD);
> }
> @@ -2704,6 +2708,7 @@ static void scsi_disk_base_class_initfn(ObjectClass
> *klass, void *data)
> dc->reset = scsi_disk_reset;
> sdc->dma_readv = scsi_dma_readv;
> sdc->dma_writev = scsi_dma_writev;
> + sdc->need_fua_emulation = scsi_is_cmd_fua;
> }
>
> static const TypeInfo scsi_disk_base_info = {
> --
> 2.5.5
>
>
>
