Re: [Qemu-devel] [PATCH v5] spapr-vscsi: add task management

[Paolo Bonzini <pbonzini@redhat.com>]

Il 29/07/2013 06:49, Alexey Kardashevskiy ha scritto:
> At the moment the guest kernel issues two types of task management
> requests to the hypervisor - task about and lun reset. This adds
> handling for these tasks. As spapr-vscsi starts calling scsi_req_cancel(),
> free_request callback was implemented.
> 
> As virtio-vscsi, spapr-vscsi does not handle CLEAR_ACA either as CDB
> control byte does not seem to be used at all so NACA bit is not
> set to the guest so the guest has no good reason to call CLEAR_ACA task.
> 
> Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
> ---
> Changes:
> 2013/07/29 (v5):
> * sending response on task management was fixed not to use vscsi_send_rsp()
> as it is unable to send response data
> 
> 2013/07/26:
> * fixed error handling
> 
> 2013/07/23:
> * remove unnecessary free_request callback
> 
> 2013/07/22:
> * fixed LUN_RESET (it used to clear requests while it should reset a device)
> * added handling of ABORT_TASK_SET/CLEAR_TASK_SET
> 
> Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
> ---
>  hw/scsi/spapr_vscsi.c | 117 ++++++++++++++++++++++++++++++++++++++------------
>  hw/scsi/srp.h         |   7 +++
>  2 files changed, 96 insertions(+), 28 deletions(-)
> 
> diff --git a/hw/scsi/spapr_vscsi.c b/hw/scsi/spapr_vscsi.c
> index 541ffcc..8e49d0d 100644
> --- a/hw/scsi/spapr_vscsi.c
> +++ b/hw/scsi/spapr_vscsi.c
> @@ -118,6 +118,20 @@ static struct vscsi_req *vscsi_get_req(VSCSIState *s)
>      return NULL;
>  }
>  
> +static struct vscsi_req *vscsi_find_req(VSCSIState *s, uint64_t srp_tag)
> +{
> +    vscsi_req *req;
> +    int i;
> +
> +    for (i = 0; i < VSCSI_REQ_LIMIT; i++) {
> +        req = &s->reqs[i];
> +        if (req->iu.srp.cmd.tag == srp_tag) {
> +            return req;
> +        }
> +    }
> +    return NULL;
> +}
> +
>  static void vscsi_put_req(vscsi_req *req)
>  {
>      if (req->sreq != NULL) {
> @@ -654,40 +668,87 @@ static int vscsi_queue_cmd(VSCSIState *s, vscsi_req *req)
>  static int vscsi_process_tsk_mgmt(VSCSIState *s, vscsi_req *req)
>  {
>      union viosrp_iu *iu = &req->iu;
> -    int fn;
> +    vscsi_req *tmpreq;
> +    int i, lun = 0, resp = SRP_TSK_MGMT_COMPLETE;
> +    SCSIDevice *d;
> +    uint64_t tag = iu->srp.rsp.tag;
> +    uint8_t sol_not = iu->srp.cmd.sol_not;
>  
>      fprintf(stderr, "vscsi_process_tsk_mgmt %02x\n",
>              iu->srp.tsk_mgmt.tsk_mgmt_func);
>  
> -    switch (iu->srp.tsk_mgmt.tsk_mgmt_func) {
> -#if 0 /* We really don't deal with these for now */
> -    case SRP_TSK_ABORT_TASK:
> -        fn = ABORT_TASK;
> -        break;
> -    case SRP_TSK_ABORT_TASK_SET:
> -        fn = ABORT_TASK_SET;
> -        break;
> -    case SRP_TSK_CLEAR_TASK_SET:
> -        fn = CLEAR_TASK_SET;
> -        break;
> -    case SRP_TSK_LUN_RESET:
> -        fn = LOGICAL_UNIT_RESET;
> -        break;
> -    case SRP_TSK_CLEAR_ACA:
> -        fn = CLEAR_ACA;
> -        break;
> -#endif
> -    default:
> -        fn = 0;
> -    }
> -    if (fn) {
> -        /* XXX Send/Handle target task management */
> -        ;
> +    d = vscsi_device_find(&s->bus, be64_to_cpu(req->iu.srp.tsk_mgmt.lun), &lun);
> +    if (!d) {
> +        resp = SRP_TSK_MGMT_FIELDS_INVALID;
>      } else {
> -        vscsi_makeup_sense(s, req, ILLEGAL_REQUEST, 0x20, 0);
> -        vscsi_send_rsp(s, req, CHECK_CONDITION, 0, 0);
> +        switch (iu->srp.tsk_mgmt.tsk_mgmt_func) {
> +        case SRP_TSK_ABORT_TASK:
> +            if (d->lun != lun) {
> +                resp = SRP_TSK_MGMT_FIELDS_INVALID;
> +                break;
> +            }
> +
> +            tmpreq = vscsi_find_req(s, req->iu.srp.tsk_mgmt.task_tag);
> +            if (tmpreq && tmpreq->sreq) {
> +                assert(tmpreq->sreq->hba_private);
> +                scsi_req_cancel(tmpreq->sreq);
> +            }
> +            break;
> +
> +        case SRP_TSK_LUN_RESET:
> +            if (d->lun != lun) {
> +                resp = SRP_TSK_MGMT_FIELDS_INVALID;
> +                break;
> +            }
> +
> +            qdev_reset_all(&d->qdev);
> +            break;
> +
> +        case SRP_TSK_ABORT_TASK_SET:
> +        case SRP_TSK_CLEAR_TASK_SET:
> +            if (d->lun != lun) {
> +                resp = SRP_TSK_MGMT_FIELDS_INVALID;
> +                break;
> +            }
> +
> +            for (i = 0; i < VSCSI_REQ_LIMIT; i++) {
> +                tmpreq = &s->reqs[i];
> +                if (tmpreq->iu.srp.cmd.lun != req->iu.srp.tsk_mgmt.lun) {
> +                    continue;
> +                }
> +                if (!tmpreq->active || !tmpreq->sreq) {
> +                    continue;
> +                }
> +                assert(tmpreq->sreq->hba_private);
> +                scsi_req_cancel(tmpreq->sreq);
> +            }
> +            break;
> +
> +        case SRP_TSK_CLEAR_ACA:
> +            resp = SRP_TSK_MGMT_NOT_SUPPORTED;
> +            break;
> +
> +        default:
> +            resp = SRP_TSK_MGMT_FIELDS_INVALID;
> +            break;
> +        }
>      }
> -    return !fn;
> +
> +    /* Compose the response here as  */
> +    memset(iu, 0, sizeof(struct srp_rsp) + 4);
> +    iu->srp.rsp.opcode = SRP_RSP;
> +    iu->srp.rsp.req_lim_delta = cpu_to_be32(1);
> +    iu->srp.rsp.tag = tag;
> +    iu->srp.rsp.flags |= SRP_RSP_FLAG_RSPVALID;
> +    iu->srp.rsp.resp_data_len = cpu_to_be32(4);
> +    /* Copy UCSOLNT bit as SRP_RSP_FLAG_RSPVALID is set */
> +    iu->srp.rsp.sol_not = (sol_not & 0x04) >> 1;

This is ">> 2" and also needs to look at SCSOLNT with the same rules as
normal responses, but I can fix this when applying.

Thanks for both patches.

Paolo

> +    iu->srp.rsp.status = GOOD;
> +    iu->srp.rsp.data[3] = resp;
> +
> +    vscsi_send_iu(s, req, sizeof(iu->srp.rsp) + 4, VIOSRP_SRP_FORMAT);
> +
> +    return 1;
>  }
>  
>  static int vscsi_handle_srp_req(VSCSIState *s, vscsi_req *req)
> diff --git a/hw/scsi/srp.h b/hw/scsi/srp.h
> index 5e0cad5..d27f31d 100644
> --- a/hw/scsi/srp.h
> +++ b/hw/scsi/srp.h
> @@ -90,6 +90,13 @@ enum {
>      SRP_REV16A_IB_IO_CLASS = 0x0100
>  };
>  
> +enum {
> +    SRP_TSK_MGMT_COMPLETE       = 0x00,
> +    SRP_TSK_MGMT_FIELDS_INVALID = 0x02,
> +    SRP_TSK_MGMT_NOT_SUPPORTED  = 0x04,
> +    SRP_TSK_MGMT_FAILED         = 0x05
> +};
> +
>  struct srp_direct_buf {
>      uint64_t    va;
>      uint32_t    key;
>