scsi: explicitly list guest-recoverable sense codes

It's not really possible to fit all sense codes into errno codes,
especially in such a way that sense codes can be properly categorized as
either guest-recoverable or host-handled.  Create a new function that
checks for guest recoverable sense, then scsi_sense_buf_to_errno only
needs to be called for host handled sense codes.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

hw/scsi/scsi-disk.c

@@ -454,14 +454,13 @@ static bool scsi_handle_rw_error(SCSIDiskReq *r, int error, bool acct_failed)
              * pause the host.
              */
             assert(r->status && *r->status);
-            error = scsi_sense_buf_to_errno(r->req.sense, sizeof(r->req.sense));
+            if (scsi_sense_buf_is_guest_recoverable(r->req.sense, sizeof(r->req.sense))) {
-            if (error == ECANCELED || error == EAGAIN || error == ENOTCONN ||
-                error == 0)  {
                 /* These errors are handled by guest. */
                 sdc->update_sense(&r->req);
                 scsi_req_complete(&r->req, *r->status);
                 return true;
             }
+            error = scsi_sense_buf_to_errno(r->req.sense, sizeof(r->req.sense));
             break;
         case ENOMEDIUM:
             scsi_check_condition(r, SENSE_CODE(NO_MEDIUM));

include/scsi/utils.h

@@ -106,6 +106,7 @@ extern const struct SCSISense sense_code_SPACE_ALLOC_FAILED;
 
 int scsi_sense_to_errno(int key, int asc, int ascq);
 int scsi_sense_buf_to_errno(const uint8_t *sense, size_t sense_size);
+bool scsi_sense_buf_is_guest_recoverable(const uint8_t *sense, size_t sense_size);
 
 int scsi_convert_sense(uint8_t *in_buf, int in_len,
                        uint8_t *buf, int len, bool fixed);

scsi/utils.c

@@ -336,6 +336,38 @@ int scsi_convert_sense(uint8_t *in_buf, int in_len,
     }
 }
 
+static bool scsi_sense_is_guest_recoverable(int key, int asc, int ascq)
+{
+    switch (key) {
+    case NO_SENSE:
+    case RECOVERED_ERROR:
+    case UNIT_ATTENTION:
+    case ABORTED_COMMAND:
+        return true;
+    case NOT_READY:
+    case ILLEGAL_REQUEST:
+    case DATA_PROTECT:
+        /* Parse ASCQ */
+        break;
+    default:
+        return false;
+    }
+
+    switch ((asc << 8) | ascq) {
+    case 0x1a00: /* PARAMETER LIST LENGTH ERROR */
+    case 0x2000: /* INVALID OPERATION CODE */
+    case 0x2400: /* INVALID FIELD IN CDB */
+    case 0x2500: /* LOGICAL UNIT NOT SUPPORTED */
+    case 0x2600: /* INVALID FIELD IN PARAMETER LIST */
+
+    case 0x0401: /* NOT READY, IN PROGRESS OF BECOMING READY */
+    case 0x0402: /* NOT READY, INITIALIZING COMMAND REQUIRED */
+        return true;
+    default:
+        return false;
+    }
+}
+
 int scsi_sense_to_errno(int key, int asc, int ascq)
 {
     switch (key) {
@@ -391,6 +423,17 @@ int scsi_sense_buf_to_errno(const uint8_t *in_buf, size_t in_len)
     return scsi_sense_to_errno(sense.key, sense.asc, sense.ascq);
 }
 
+bool scsi_sense_buf_is_guest_recoverable(const uint8_t *in_buf, size_t in_len)
+{
+    SCSISense sense;
+    if (in_len < 1) {
+        return false;
+    }
+
+    sense = scsi_parse_sense_buf(in_buf, in_len);
+    return scsi_sense_is_guest_recoverable(sense.key, sense.asc, sense.ascq);
+}
+
 const char *scsi_command_name(uint8_t cmd)
 {
     static const char *names[] = {