scsi: move sense handling to generic code

With this patch, sense data is stored in the generic data structures
for SCSI devices and requests.  The SCSI layer takes care of storing
sense data in the SCSIDevice for the subsequent REQUEST SENSE command.

At the same time, get_sense is removed and scsi_req_get_sense can use
an entirely generic implementation.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

1 files changed, 62 insertions, 5 deletions

diff --git a/hw/scsi-bus.c b/hw/scsi-bus.c
index 9637ccb..af95670 100644
--- a/hw/scsi-bus.c
+++ b/hw/scsi-bus.c
@@ -7,6 +7,8 @@
 #include "trace.h"
 
 static char *scsibus_get_fw_dev_path(DeviceState *dev);
+static int scsi_build_sense(uint8_t *in_buf, int in_len,
+                            uint8_t *buf, int len, bool fixed);
 
 static struct BusInfo scsi_bus_info = {
     .name  = "SCSI",
@@ -144,6 +146,7 @@ SCSIRequest *scsi_req_alloc(size_t size, SCSIDevice *d, uint32_t tag,
     req->lun = lun;
     req->hba_private = hba_private;
     req->status = -1;
+    req->sense_len = 0;
     trace_scsi_req_alloc(req->dev->id, req->lun, req->tag);
     return req;
 }
@@ -161,11 +164,28 @@ uint8_t *scsi_req_get_buf(SCSIRequest *req)
 
 int scsi_req_get_sense(SCSIRequest *req, uint8_t *buf, int len)
 {
-    if (req->dev->info->get_sense) {
-        return req->dev->info->get_sense(req, buf, len);
-    } else {
+    assert(len >= 14);
+    if (!req->sense_len) {
         return 0;
     }
+    return scsi_build_sense(req->sense, req->sense_len, buf, len, true);
+}
+
+int scsi_device_get_sense(SCSIDevice *dev, uint8_t *buf, int len, bool fixed)
+{
+    return scsi_build_sense(dev->sense, dev->sense_len, buf, len, fixed);
+}
+
+void scsi_req_build_sense(SCSIRequest *req, SCSISense sense)
+{
+    trace_scsi_req_build_sense(req->dev->id, req->lun, req->tag,
+                               sense.key, sense.asc, sense.ascq);
+    memset(req->sense, 0, 18);
+    req->sense[0] = 0xf0;
+    req->sense[2] = sense.key;
+    req->sense[12] = sense.asc;
+    req->sense[13] = sense.ascq;
+    req->sense_len = 18;
 }
 
 int32_t scsi_req_enqueue(SCSIRequest *req, uint8_t *buf)
@@ -484,14 +504,40 @@ const struct SCSISense sense_code_LUN_FAILURE = {
 /*
  * scsi_build_sense
  *
- * Build a sense buffer
+ * Convert between fixed and descriptor sense buffers
  */
-int scsi_build_sense(SCSISense sense, uint8_t *buf, int len, int fixed)
+int scsi_build_sense(uint8_t *in_buf, int in_len,
+                     uint8_t *buf, int len, bool fixed)
 {
+    bool fixed_in;
+    SCSISense sense;
     if (!fixed && len < 8) {
         return 0;
     }
 
+    if (in_len == 0) {
+        sense.key = NO_SENSE;
+        sense.asc = 0;
+        sense.ascq = 0;
+    } else {
+        fixed_in = (in_buf[0] & 2) == 0;
+
+        if (fixed == fixed_in) {
+            memcpy(buf, in_buf, MIN(len, in_len));
+            return MIN(len, in_len);
+        }
+
+        if (fixed_in) {
+            sense.key = in_buf[2];
+            sense.asc = in_buf[12];
+            sense.ascq = in_buf[13];
+        } else {
+            sense.key = in_buf[1];
+            sense.asc = in_buf[2];
+            sense.ascq = in_buf[3];
+        }
+    }
+
     memset(buf, 0, len);
     if (fixed) {
         /* Return fixed format sense buffer */
@@ -686,6 +732,17 @@ void scsi_req_complete(SCSIRequest *req, int status)
 {
     assert(req->status == -1);
     req->status = status;
+
+    assert(req->sense_len < sizeof(req->sense));
+    if (status == GOOD) {
+        req->sense_len = 0;
+    }
+
+    if (req->sense_len) {
+        memcpy(req->dev->sense, req->sense, req->sense_len);
+    }
+    req->dev->sense_len = req->sense_len;
+
     scsi_req_ref(req);
     scsi_req_dequeue(req);
     req->bus->ops->complete(req, req->status);