scsi: Implement 'get_sense' callback

The get_sense callback copies existing sense information into
the provided buffer. This is required if sense information
should be transferred together with the command response.
Signed-off-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>

hw/scsi-bus.c

@@ -156,6 +156,15 @@ uint8_t *scsi_req_get_buf(SCSIRequest *req)
     return req->dev->info->get_buf(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 {
+        return 0;
+    }
+}
+
 int32_t scsi_req_enqueue(SCSIRequest *req, uint8_t *buf)
 {
     int32_t rc;

hw/scsi-disk.c

@@ -340,6 +340,14 @@ static uint8_t *scsi_get_buf(SCSIRequest *req)
     return (uint8_t *)r->iov.iov_base;
 }
 
+/* Copy sense information into the provided buffer */
+static int scsi_get_sense(SCSIRequest *req, uint8_t *outbuf, int len)
+{
+    SCSIDiskState *s = DO_UPCAST(SCSIDiskState, qdev, req->dev);
+
+    return scsi_build_sense(s->sense, outbuf, len, len > 14);
+}
+
 static int scsi_disk_emulate_inquiry(SCSIRequest *req, uint8_t *outbuf)
 {
     SCSIDiskState *s = DO_UPCAST(SCSIDiskState, qdev, req->dev);
@@ -1257,6 +1265,7 @@ static SCSIDeviceInfo scsi_disk_info[] = {
         .write_data   = scsi_write_data,
         .cancel_io    = scsi_cancel_io,
         .get_buf      = scsi_get_buf,
+        .get_sense    = scsi_get_sense,
         .qdev.props   = (Property[]) {
             DEFINE_SCSI_DISK_PROPERTIES(),
             DEFINE_PROP_BIT("removable", SCSIDiskState, removable, 0, false),
@@ -1277,6 +1286,7 @@ static SCSIDeviceInfo scsi_disk_info[] = {
         .write_data   = scsi_write_data,
         .cancel_io    = scsi_cancel_io,
         .get_buf      = scsi_get_buf,
+        .get_sense    = scsi_get_sense,
         .qdev.props   = (Property[]) {
             DEFINE_SCSI_DISK_PROPERTIES(),
             DEFINE_PROP_END_OF_LIST(),
@@ -1296,6 +1306,7 @@ static SCSIDeviceInfo scsi_disk_info[] = {
         .write_data   = scsi_write_data,
         .cancel_io    = scsi_cancel_io,
         .get_buf      = scsi_get_buf,
+        .get_sense    = scsi_get_sense,
         .qdev.props   = (Property[]) {
             DEFINE_SCSI_DISK_PROPERTIES(),
             DEFINE_PROP_BIT("removable", SCSIDiskState, removable, 0, false),

hw/scsi-generic.c

@@ -79,6 +79,23 @@ static void scsi_clear_sense(SCSIGenericState *s)
     s->driver_status = 0;
 }
 
+static int scsi_get_sense(SCSIRequest *req, uint8_t *outbuf, int len)
+{
+    SCSIGenericState *s = DO_UPCAST(SCSIGenericState, qdev, req->dev);
+    int size = SCSI_SENSE_BUF_SIZE;
+
+    if (!(s->driver_status & SG_ERR_DRIVER_SENSE)) {
+        size = scsi_build_sense(SENSE_CODE(NO_SENSE), s->sensebuf,
+                                SCSI_SENSE_BUF_SIZE, 0);
+    }
+    if (size > len) {
+        size = len;
+    }
+    memcpy(outbuf, s->sensebuf, size);
+
+    return size;
+}
+
 static SCSIRequest *scsi_new_request(SCSIDevice *d, uint32_t tag, uint32_t lun)
 {
     SCSIRequest *req;
@@ -535,6 +552,7 @@ static SCSIDeviceInfo scsi_generic_info = {
     .write_data   = scsi_write_data,
     .cancel_io    = scsi_cancel_io,
     .get_buf      = scsi_get_buf,
+    .get_sense    = scsi_get_sense,
     .qdev.props   = (Property[]) {
         DEFINE_BLOCK_PROPERTIES(SCSIGenericState, qdev.conf),
         DEFINE_PROP_END_OF_LIST(),

hw/scsi.h

@@ -80,6 +80,7 @@ struct SCSIDeviceInfo {
     int (*write_data)(SCSIRequest *req);
     void (*cancel_io)(SCSIRequest *req);
     uint8_t *(*get_buf)(SCSIRequest *req);
+    int (*get_sense)(SCSIRequest *req, uint8_t *buf, int len);
 };
 
 struct SCSIBusOps {
@@ -155,6 +156,7 @@ void scsi_req_continue(SCSIRequest *req);
 void scsi_req_data(SCSIRequest *req, int len);
 void scsi_req_complete(SCSIRequest *req);
 uint8_t *scsi_req_get_buf(SCSIRequest *req);
+int scsi_req_get_sense(SCSIRequest *req, uint8_t *buf, int len);
 void scsi_req_abort(SCSIRequest *req, int status);
 void scsi_req_cancel(SCSIRequest *req);
 void scsi_device_purge_requests(SCSIDevice *sdev);

hw/spapr_vscsi.c

@@ -450,6 +450,15 @@ static void vscsi_send_request_sense(VSCSIState *s, vscsi_req *req)
     uint8_t *cdb = req->iu.srp.cmd.cdb;
     int n;
 
+    n = scsi_req_get_sense(req->sreq, req->sense, sizeof(req->sense));
+    if (n) {
+        req->senselen = n;
+        vscsi_send_rsp(s, req, CHECK_CONDITION, 0, 0);
+        vscsi_put_req(s, req);
+        return;
+    }
+
+    dprintf("VSCSI: Got CHECK_CONDITION, requesting sense...\n");
     cdb[0] = 3;
     cdb[1] = 0;
     cdb[2] = 0;
@@ -522,7 +531,6 @@ static void vscsi_command_complete(SCSIRequest *sreq, int reason, uint32_t arg)
             }
             vscsi_send_rsp(s, req, 0, res_in, res_out);
         } else if (arg == CHECK_CONDITION) {
-            dprintf("VSCSI: Got CHECK_CONDITION, requesting sense...\n");
             vscsi_send_request_sense(s, req);
             return;
         } else {