nvme: fix identify to be NVMe 1.1 compliant

NVMe 1.1 requires devices to implement a Namespace List subcommand of
the identify command.  Qemu not only not implements this features, but
also misinterprets it as an Identify Controller request.  Due to this
any OS trying to use the Namespace List will fail the probe.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

hw/block/nvme.c

@@ -469,19 +469,22 @@ static uint16_t nvme_create_cq(NvmeCtrl *n, NvmeCmd *cmd)
     return NVME_SUCCESS;
 }
 
-static uint16_t nvme_identify(NvmeCtrl *n, NvmeCmd *cmd)
+static uint16_t nvme_identify_ctrl(NvmeCtrl *n, NvmeIdentify *c)
+{
+    uint64_t prp1 = le64_to_cpu(c->prp1);
+    uint64_t prp2 = le64_to_cpu(c->prp2);
+
+    return nvme_dma_read_prp(n, (uint8_t *)&n->id_ctrl, sizeof(n->id_ctrl),
+        prp1, prp2);
+}
+
+static uint16_t nvme_identify_ns(NvmeCtrl *n, NvmeIdentify *c)
 {
     NvmeNamespace *ns;
-    NvmeIdentify *c = (NvmeIdentify *)cmd;
-    uint32_t cns  = le32_to_cpu(c->cns);
     uint32_t nsid = le32_to_cpu(c->nsid);
     uint64_t prp1 = le64_to_cpu(c->prp1);
     uint64_t prp2 = le64_to_cpu(c->prp2);
 
-    if (cns) {
-        return nvme_dma_read_prp(n, (uint8_t *)&n->id_ctrl, sizeof(n->id_ctrl),
-            prp1, prp2);
-    }
     if (nsid == 0 || nsid > n->num_namespaces) {
         return NVME_INVALID_NSID | NVME_DNR;
     }
@@ -491,6 +494,48 @@ static uint16_t nvme_identify(NvmeCtrl *n, NvmeCmd *cmd)
         prp1, prp2);
 }
 
+static uint16_t nvme_identify_nslist(NvmeCtrl *n, NvmeIdentify *c)
+{
+    static const int data_len = 4096;
+    uint32_t min_nsid = le32_to_cpu(c->nsid);
+    uint64_t prp1 = le64_to_cpu(c->prp1);
+    uint64_t prp2 = le64_to_cpu(c->prp2);
+    uint32_t *list;
+    uint16_t ret;
+    int i, j = 0;
+
+    list = g_malloc0(data_len);
+    for (i = 0; i < n->num_namespaces; i++) {
+        if (i < min_nsid) {
+            continue;
+        }
+        list[j++] = cpu_to_le32(i + 1);
+        if (j == data_len / sizeof(uint32_t)) {
+            break;
+        }
+    }
+    ret = nvme_dma_read_prp(n, (uint8_t *)list, data_len, prp1, prp2);
+    g_free(list);
+    return ret;
+}
+
+
+static uint16_t nvme_identify(NvmeCtrl *n, NvmeCmd *cmd)
+{
+    NvmeIdentify *c = (NvmeIdentify *)cmd;
+
+    switch (le32_to_cpu(c->cns)) {
+    case 0x00:
+        return nvme_identify_ns(n, c);
+    case 0x01:
+        return nvme_identify_ctrl(n, c);
+    case 0x02:
+        return nvme_identify_nslist(n, c);
+    default:
+        return NVME_INVALID_FIELD | NVME_DNR;
+    }
+}
+
 static uint16_t nvme_get_feature(NvmeCtrl *n, NvmeCmd *cmd, NvmeRequest *req)
 {
     uint32_t dw10 = le32_to_cpu(cmd->cdw10);