From: Jeuk Kim <jeuk20.kim@samsung.com>

MCQ requests are allocated with their SQ, but can remain in flight on the
CQ list or in the SCSI layer after leaving the SQ free list.

Reject runtime SQ deletion while any request is still outstanding, and
use separate teardown helpers so device exit can still release MCQ
queues after child devices have been unrealized.

Fixes: 5c079578d2e ("hw/ufs: Add support MCQ of UFSHCI 4.0")
Cc: qemu-stable@nongnu.org
Signed-off-by: Jeuk Kim <jeuk20.kim@samsung.com>
(cherry picked from commit 619c2da19a05668dabe7912afb789e50b8635c4d)
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>

diff --git a/hw/ufs/trace-events b/hw/ufs/trace-events
index 7734b35f08..6f7ea9c95f 100644
--- a/hw/ufs/trace-events
+++ b/hw/ufs/trace-events
@@ -44,6 +44,7 @@ ufs_err_mcq_create_sq_invalid_size(uint8_t qid) "invalid mcq sq size for sqid %"
 ufs_err_mcq_create_sq_already_exists(uint8_t qid) "mcq sqid %"PRIu8 "already exists"
 ufs_err_mcq_delete_sq_invalid_sqid(uint8_t qid) "invalid mcq sqid %"PRIu8""
 ufs_err_mcq_delete_sq_not_exists(uint8_t qid) "mcq sqid %"PRIu8 "not exists"
+ufs_err_mcq_delete_sq_busy(uint8_t qid) "mcq sqid %"PRIu8" has outstanding requests"
 ufs_err_mcq_create_cq_invalid_cqid(uint8_t qid) "invalid mcq cqid %"PRIu8""
 ufs_err_mcq_create_cq_invalid_size(uint8_t qid) "invalid mcq cq size for cqid %"PRIu8""
 ufs_err_mcq_create_cq_already_exists(uint8_t qid) "mcq cqid %"PRIu8 "already exists"
diff --git a/hw/ufs/ufs.c b/hw/ufs/ufs.c
index 66f4031852..d63a8f9c9c 100644
--- a/hw/ufs/ufs.c
+++ b/hw/ufs/ufs.c
@@ -556,6 +556,31 @@ static bool ufs_mcq_create_sq(UfsHc *u, uint8_t qid, uint32_t attr)
     return true;
 }
 
+static bool ufs_mcq_sq_has_outstanding_req(UfsSq *sq)
+{
+    UfsRequest *req;
+    uint16_t free_reqs = 0;
+
+    QTAILQ_FOREACH(req, &sq->req_list, entry)
+    {
+        free_reqs++;
+    }
+
+    return free_reqs != sq->size;
+}
+
+static void ufs_mcq_free_sq(UfsSq *sq)
+{
+    qemu_bh_delete(sq->bh);
+
+    for (int i = 0; i < sq->size; i++) {
+        ufs_clear_req(&sq->req[i]);
+    }
+
+    g_free(sq->req);
+    g_free(sq);
+}
+
 static bool ufs_mcq_delete_sq(UfsHc *u, uint8_t qid)
 {
     UfsSq *sq;
@@ -572,9 +597,12 @@ static bool ufs_mcq_delete_sq(UfsHc *u, uint8_t qid)
 
     sq = u->sq[qid];
 
-    qemu_bh_delete(sq->bh);
-    g_free(sq->req);
-    g_free(sq);
+    if (ufs_mcq_sq_has_outstanding_req(sq)) {
+        trace_ufs_err_mcq_delete_sq_busy(qid);
+        return false;
+    }
+
+    ufs_mcq_free_sq(sq);
     u->sq[qid] = NULL;
     return true;
 }
@@ -617,6 +645,12 @@ static bool ufs_mcq_create_cq(UfsHc *u, uint8_t qid, uint32_t attr)
     return true;
 }
 
+static void ufs_mcq_free_cq(UfsCq *cq)
+{
+    qemu_bh_delete(cq->bh);
+    g_free(cq);
+}
+
 static bool ufs_mcq_delete_cq(UfsHc *u, uint8_t qid)
 {
     UfsCq *cq;
@@ -640,8 +674,7 @@ static bool ufs_mcq_delete_cq(UfsHc *u, uint8_t qid)
 
     cq = u->cq[qid];
 
-    qemu_bh_delete(cq->bh);
-    g_free(cq);
+    ufs_mcq_free_cq(cq);
     u->cq[qid] = NULL;
     return true;
 }
@@ -1884,12 +1917,14 @@ static void ufs_exit(PCIDevice *pci_dev)
 
     for (int i = 0; i < ARRAY_SIZE(u->sq); i++) {
         if (u->sq[i]) {
-            ufs_mcq_delete_sq(u, i);
+            ufs_mcq_free_sq(u->sq[i]);
+            u->sq[i] = NULL;
         }
     }
     for (int i = 0; i < ARRAY_SIZE(u->cq); i++) {
         if (u->cq[i]) {
-            ufs_mcq_delete_cq(u, i);
+            ufs_mcq_free_cq(u->cq[i]);
+            u->cq[i] = NULL;
         }
     }
 }
-- 
2.47.3