[Qemu-devel] [PATCH v2] spapr-vscsi: add task management

[Alexey Kardashevskiy <aik@ozlabs.ru>]

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:
2013/07/22:
* 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 | 73 +++++++++++++++++++++++++++++++++++++++------------
 1 file changed, 56 insertions(+), 17 deletions(-)

diff --git a/hw/scsi/spapr_vscsi.c b/hw/scsi/spapr_vscsi.c
index a86199b..f1e0e8f 100644
--- a/hw/scsi/spapr_vscsi.c
+++ b/hw/scsi/spapr_vscsi.c
@@ -117,6 +117,20 @@ 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) {
@@ -578,6 +592,13 @@ static void vscsi_request_cancelled(SCSIRequest *sreq)
     vscsi_put_req(req);
 }
 
+static void vscsi_free_request(SCSIBus *bus, void *priv)
+{
+    vscsi_req *req = priv;
+
+    vscsi_put_req(req);
+}
+
 static const VMStateDescription vmstate_spapr_vscsi_req = {
     .name = "spapr_vscsi_req",
     .version_id = 1,
@@ -753,40 +774,57 @@ 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;
+    SCSIDevice *sdev;
+    int i, lun = 0, error = 0;
 
     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;
+        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:
+        sdev = vscsi_device_find(&s->bus, req->iu.srp.tsk_mgmt.lun, &lun);
+        if (sdev) {
+            qdev_reset_all(&sdev->qdev);
+        }
+        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;
+        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:
-        fn = CLEAR_ACA;
-        break;
-#endif
     default:
-        fn = 0;
+        error = 1;
     }
-    if (fn) {
-        /* XXX Send/Handle target task management */
-        ;
+
+    if (!error) {
+        vscsi_send_rsp(s, req, GOOD, 0, 0);
     } else {
         vscsi_makeup_sense(s, req, ILLEGAL_REQUEST, 0x20, 0);
         vscsi_send_rsp(s, req, CHECK_CONDITION, 0, 0);
     }
-    return !fn;
+
+    return 1;
 }
 
 static int vscsi_handle_srp_req(VSCSIState *s, vscsi_req *req)
@@ -998,6 +1036,7 @@ static const struct SCSIBusInfo vscsi_scsi_info = {
     .cancel = vscsi_request_cancelled,
     .save_request = vscsi_save_request,
     .load_request = vscsi_load_request,
+    .free_request = vscsi_free_request,
 };
 
 static void spapr_vscsi_reset(VIOsPAPRDevice *dev)
-- 
1.8.3.2