2 files changed, 34 insertions, 3 deletions

diff --git a/hw/scsi/scsi-bus.c b/hw/scsi/scsi-bus.c
index f80f4cb4fc..f083373021 100644
--- a/hw/scsi/scsi-bus.c
+++ b/hw/scsi/scsi-bus.c
@@ -412,19 +412,35 @@ static const struct SCSIReqOps reqops_invalid_opcode = {
 
 /* SCSIReqOps implementation for unit attention conditions.  */
 
-static int32_t scsi_unit_attention(SCSIRequest *req, uint8_t *buf)
+static void scsi_fetch_unit_attention_sense(SCSIRequest *req)
 {
+    SCSISense *ua = NULL;
+
     if (req->dev->unit_attention.key == UNIT_ATTENTION) {
-        scsi_req_build_sense(req, req->dev->unit_attention);
+        ua = &req->dev->unit_attention;
     } else if (req->bus->unit_attention.key == UNIT_ATTENTION) {
-        scsi_req_build_sense(req, req->bus->unit_attention);
+        ua = &req->bus->unit_attention;
     }
+
+    /*
+     * Fetch the unit attention sense immediately so that another
+     * scsi_req_new does not use reqops_unit_attention.
+     */
+    if (ua) {
+        scsi_req_build_sense(req, *ua);
+        *ua = SENSE_CODE(NO_SENSE);
+    }
+}
+
+static int32_t scsi_unit_attention(SCSIRequest *req, uint8_t *buf)
+{
     scsi_req_complete(req, CHECK_CONDITION);
     return 0;
 }
 
 static const struct SCSIReqOps reqops_unit_attention = {
     .size         = sizeof(SCSIRequest),
+    .init_req     = scsi_fetch_unit_attention_sense,
     .send_command = scsi_unit_attention
 };
 
@@ -699,6 +715,11 @@ SCSIRequest *scsi_req_alloc(const SCSIReqOps *reqops, SCSIDevice *d,
     object_ref(OBJECT(d));
     object_ref(OBJECT(qbus->parent));
     notifier_list_init(&req->cancel_notifiers);
+
+    if (reqops->init_req) {
+        reqops->init_req(req);
+    }
+
     trace_scsi_req_alloc(req->dev->id, req->lun, req->tag);
     return req;
 }
@@ -798,6 +819,15 @@ uint8_t *scsi_req_get_buf(SCSIRequest *req)
 static void scsi_clear_unit_attention(SCSIRequest *req)
 {
     SCSISense *ua;
+
+    /*
+     * scsi_fetch_unit_attention_sense() already cleaned the unit attention
+     * in this case.
+     */
+    if (req->ops == &reqops_unit_attention) {
+        return;
+    }
+
     if (req->dev->unit_attention.key != UNIT_ATTENTION &&
         req->bus->unit_attention.key != UNIT_ATTENTION) {
         return;
diff --git a/include/hw/scsi/scsi.h b/include/hw/scsi/scsi.h
index e2bb1a2fbf..3692ca82f3 100644
--- a/include/hw/scsi/scsi.h
+++ b/include/hw/scsi/scsi.h
@@ -108,6 +108,7 @@ int cdrom_read_toc_raw(int nb_sectors, uint8_t *buf, int msf, int session_num);
 /* scsi-bus.c */
 struct SCSIReqOps {
     size_t size;
+    void (*init_req)(SCSIRequest *req);
     void (*free_req)(SCSIRequest *req);
     int32_t (*send_command)(SCSIRequest *req, uint8_t *buf);
     void (*read_data)(SCSIRequest *req);