[Qemu-devel] [RFC PATCH] 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.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
---

I still do not have really good test to test the task management, any working ideas? :)

This is made on top of "pseries: rework PAPR virtual SCSI" which some day may make it to upstream.

---
 hw/scsi/spapr_vscsi.c | 84 +++++++++++++++++++++++++++++++++++++++------------
 1 file changed, 64 insertions(+), 20 deletions(-)

diff --git a/hw/scsi/spapr_vscsi.c b/hw/scsi/spapr_vscsi.c
index a86199b..6b90c9c 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) {
@@ -641,6 +655,13 @@ static void *vscsi_load_request(QEMUFile *f, SCSIRequest *sreq)
     return req;
 }
 
+static void vscsi_free_request(SCSIBus *bus, void *priv)
+{
+    vscsi_req *req = priv;
+
+    vscsi_put_req(req);
+}
+
 static void vscsi_process_login(VSCSIState *s, vscsi_req *req)
 {
     union viosrp_iu *iu = &req->iu;
@@ -750,43 +771,65 @@ static int vscsi_queue_cmd(VSCSIState *s, vscsi_req *req)
     return 0;
 }
 
+/*
+ * The SRP services request the SRP initiator port issue an SRP_TSK_MGMT
+ * request (see 6.7) with a TASK MANAGEMENT FLAGS field set to indicate
+ * an ABORT TASK function to be sent to the selected SCSI device.
+ */
+static int vscsi_tsk_mgmt_abort_task(VSCSIState *s, vscsi_req *req)
+{
+    vscsi_req *task_req = vscsi_find_req(s, req->iu.srp.tsk_mgmt.task_tag);
+
+    scsi_req_cancel(task_req->sreq);
+
+    return 1;
+}
+
+/*
+ * The SRP services request the SRP initiator port issue an SRP_TSK_MGMT
+ * request (see 6.7) with a TASK MANAGEMENT FLAGS field set to indicate
+ * a LOGICAL UNIT RESET function to be sent to the selected SCSI device.
+ */
+static int vscsi_tsk_mgmt_lun_reset(VSCSIState *s, vscsi_req *req)
+{
+    int i;
+    vscsi_req *tmpreq;
+
+    for (i = 0; i < VSCSI_REQ_LIMIT; i++) {
+        tmpreq = &s->reqs[i];
+        if ((tmpreq->iu.srp.cmd.lun == req->iu.srp.tsk_mgmt.lun) &&
+                tmpreq->active && tmpreq->sreq) {
+            scsi_req_cancel(tmpreq->sreq);
+        }
+    }
+
+    return 1;
+}
+
 static int vscsi_process_tsk_mgmt(VSCSIState *s, vscsi_req *req)
 {
     union viosrp_iu *iu = &req->iu;
-    int fn;
+    int ret = 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;
+        ret = vscsi_tsk_mgmt_abort_task(s, req);
+        break;
+    case SRP_TSK_LUN_RESET:
+        ret = vscsi_tsk_mgmt_lun_reset(s, req);
         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 */
-        ;
-    } else {
         vscsi_makeup_sense(s, req, ILLEGAL_REQUEST, 0x20, 0);
         vscsi_send_rsp(s, req, CHECK_CONDITION, 0, 0);
+        ret = 1;
     }
-    return !fn;
+    return ret;
 }
 
 static int vscsi_handle_srp_req(VSCSIState *s, vscsi_req *req)
@@ -998,6 +1041,7 @@ 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