scsi: introduce sg_io_sense_from_errno

Move more knowledge of SG_IO out of hw/scsi/scsi-generic.c, for
reusability.
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

hw/scsi/scsi-generic.c

@@ -81,6 +81,7 @@ static void scsi_free_request(SCSIRequest *req)
 static void scsi_command_complete_noio(SCSIGenericReq *r, int ret)
 {
     int status;
+    SCSISense sense;
 
     assert(r->req.aiocb == NULL);
 
@@ -88,42 +89,15 @@ static void scsi_command_complete_noio(SCSIGenericReq *r, int ret)
         scsi_req_cancel_complete(&r->req);
         goto done;
     }
-    if (r->io_header.driver_status & SG_ERR_DRIVER_SENSE) {
-        r->req.sense_len = r->io_header.sb_len_wr;
-    }
-
-    if (ret != 0) {
-        switch (ret) {
-        case -EDOM:
-            status = TASK_SET_FULL;
-            break;
-        case -ENOMEM:
-            status = CHECK_CONDITION;
-            scsi_req_build_sense(&r->req, SENSE_CODE(TARGET_FAILURE));
-            break;
-        default:
-            status = CHECK_CONDITION;
-            scsi_req_build_sense(&r->req, SENSE_CODE(IO_ERROR));
-            break;
-        }
-    } else {
-        if (r->io_header.host_status == SG_ERR_DID_NO_CONNECT ||
-            r->io_header.host_status == SG_ERR_DID_BUS_BUSY ||
-            r->io_header.host_status == SG_ERR_DID_TIME_OUT ||
-            (r->io_header.driver_status & SG_ERR_DRIVER_TIMEOUT)) {
-            status = BUSY;
-            BADF("Driver Timeout\n");
-        } else if (r->io_header.host_status) {
-            status = CHECK_CONDITION;
-            scsi_req_build_sense(&r->req, SENSE_CODE(I_T_NEXUS_LOSS));
-        } else if (r->io_header.status) {
-            status = r->io_header.status;
-        } else if (r->io_header.driver_status & SG_ERR_DRIVER_SENSE) {
-            status = CHECK_CONDITION;
+    status = sg_io_sense_from_errno(-ret, &r->io_header, &sense);
+    if (status == CHECK_CONDITION) {
+        if (r->io_header.driver_status & SG_ERR_DRIVER_SENSE) {
+            r->req.sense_len = r->io_header.sb_len_wr;
         } else {
-            status = GOOD;
+            scsi_req_build_sense(&r->req, sense);
         }
     }
+
     DPRINTF("Command complete 0x%p tag=0x%x status=%d\n",
             r, r->req.tag, status);
 

include/scsi/utils.h

@@ -116,6 +116,9 @@ int scsi_cdb_length(uint8_t *buf);
 #define SG_ERR_DID_TIME_OUT    0x03
 
 #define SG_ERR_DRIVER_SENSE    0x08
+
+int sg_io_sense_from_errno(int errno_value, struct sg_io_hdr *io_hdr,
+                           SCSISense *sense);
 #endif
 
 #endif

scsi/utils.c

@@ -501,3 +501,38 @@ const char *scsi_command_name(uint8_t cmd)
     }
     return names[cmd];
 }
+
+#ifdef CONFIG_LINUX
+int sg_io_sense_from_errno(int errno_value, struct sg_io_hdr *io_hdr,
+                           SCSISense *sense)
+{
+    if (errno_value != 0) {
+        switch (errno_value) {
+        case EDOM:
+            return TASK_SET_FULL;
+        case ENOMEM:
+            *sense = SENSE_CODE(TARGET_FAILURE);
+            return CHECK_CONDITION;
+        default:
+            *sense = SENSE_CODE(IO_ERROR);
+            return CHECK_CONDITION;
+        }
+    } else {
+        if (io_hdr->host_status == SG_ERR_DID_NO_CONNECT ||
+            io_hdr->host_status == SG_ERR_DID_BUS_BUSY ||
+            io_hdr->host_status == SG_ERR_DID_TIME_OUT ||
+            (io_hdr->driver_status & SG_ERR_DRIVER_TIMEOUT)) {
+            return BUSY;
+        } else if (io_hdr->host_status) {
+            *sense = SENSE_CODE(I_T_NEXUS_LOSS);
+            return CHECK_CONDITION;
+        } else if (io_hdr->status) {
+            return io_hdr->status;
+        } else if (io_hdr->driver_status & SG_ERR_DRIVER_SENSE) {
+            return CHECK_CONDITION;
+        } else {
+            return GOOD;
+        }
+    }
+}
+#endif