From: Klaus Jensen <k.jensen@samsung.com>

Support returning Command Sequence Error if Set Features on Number of
Queues is called after queues have been created.

Signed-off-by: Klaus Jensen <k.jensen@samsung.com>
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
---
 hw/block/nvme.c | 12 ++++++++++++
 hw/block/nvme.h |  1 +
 2 files changed, 13 insertions(+)

diff --git a/hw/block/nvme.c b/hw/block/nvme.c
index f40bc861facc..d88e21a14b77 100644
--- a/hw/block/nvme.c
+++ b/hw/block/nvme.c
@@ -888,6 +888,13 @@ static uint16_t nvme_create_cq(NvmeCtrl *n, NvmeCmd *cmd)
     cq = g_malloc0(sizeof(*cq));
     nvme_init_cq(cq, n, prp1, cqid, vector, qsize + 1,
         NVME_CQ_FLAGS_IEN(qflags));
+
+    /*
+     * It is only required to set qs_created when creating a completion queue;
+     * creating a submission queue without a matching completion queue will
+     * fail.
+     */
+    n->qs_created = true;
     return NVME_SUCCESS;
 }
 
@@ -1202,6 +1209,10 @@ static uint16_t nvme_set_feature(NvmeCtrl *n, NvmeCmd *cmd, NvmeRequest *req)
         blk_set_enable_write_cache(n->conf.blk, dw11 & 1);
         break;
     case NVME_NUMBER_OF_QUEUES:
+        if (n->qs_created) {
+            return NVME_CMD_SEQ_ERROR | NVME_DNR;
+        }
+
         /*
          * NVMe v1.3, Section 5.21.1.7: 0xffff is not an allowed value for NCQR
          * and NSQR.
@@ -1343,6 +1354,7 @@ static void nvme_clear_ctrl(NvmeCtrl *n)
 
     n->aer_queued = 0;
     n->outstanding_aers = 0;
+    n->qs_created = false;
 
     blk_flush(n->conf.blk);
     n->bar.cc = 0;
diff --git a/hw/block/nvme.h b/hw/block/nvme.h
index 321d37aeaca4..f72ffddae160 100644
--- a/hw/block/nvme.h
+++ b/hw/block/nvme.h
@@ -99,6 +99,7 @@ typedef struct NvmeCtrl {
     BlockConf    conf;
     NvmeParams   params;
 
+    bool        qs_created;
     uint32_t    page_size;
     uint16_t    page_bits;
     uint16_t    max_prp_ents;
-- 
2.26.0