diff --git a/hw/block/nvme.c b/hw/block/nvme.c
index 61447220a8..ee669ee8dc 100644
--- a/hw/block/nvme.c
+++ b/hw/block/nvme.c
@@ -1354,24 +1354,19 @@ static const MemoryRegionOps nvme_cmb_ops = {
     },
 };
 
-static void nvme_realize(PCIDevice *pci_dev, Error **errp)
+static void nvme_check_constraints(NvmeCtrl *n, Error **errp)
 {
-    NvmeCtrl *n = NVME(pci_dev);
-    NvmeIdCtrl *id = &n->id_ctrl;
+    NvmeParams *params = &n->params;
 
-    int i;
-    int64_t bs_size;
-    uint8_t *pci_conf;
-
-    if (n->params.num_queues) {
+    if (params->num_queues) {
         warn_report("num_queues is deprecated; please use max_ioqpairs "
                     "instead");
 
-        n->params.max_ioqpairs = n->params.num_queues - 1;
+        params->max_ioqpairs = params->num_queues - 1;
     }
 
-    if (n->params.max_ioqpairs < 1 ||
-        n->params.max_ioqpairs > PCI_MSIX_FLAGS_QSIZE) {
+    if (params->max_ioqpairs < 1 ||
+        params->max_ioqpairs > PCI_MSIX_FLAGS_QSIZE) {
         error_setg(errp, "max_ioqpairs must be between 1 and %d",
                    PCI_MSIX_FLAGS_QSIZE);
         return;
@@ -1382,13 +1377,7 @@ static void nvme_realize(PCIDevice *pci_dev, Error **errp)
         return;
     }
 
-    bs_size = blk_getlength(n->conf.blk);
-    if (bs_size < 0) {
-        error_setg(errp, "could not get backing file size");
-        return;
-    }
-
-    if (!n->params.serial) {
+    if (!params->serial) {
         error_setg(errp, "serial property not set");
         return;
     }
@@ -1408,6 +1397,29 @@ static void nvme_realize(PCIDevice *pci_dev, Error **errp)
 
         host_memory_backend_set_mapped(n->pmrdev, true);
     }
+}
+
+static void nvme_realize(PCIDevice *pci_dev, Error **errp)
+{
+    NvmeCtrl *n = NVME(pci_dev);
+    NvmeIdCtrl *id = &n->id_ctrl;
+    Error *local_err = NULL;
+
+    int i;
+    int64_t bs_size;
+    uint8_t *pci_conf;
+
+    nvme_check_constraints(n, &local_err);
+    if (local_err) {
+        error_propagate(errp, local_err);
+        return;
+    }
+
+    bs_size = blk_getlength(n->conf.blk);
+    if (bs_size < 0) {
+        error_setg(errp, "could not get backing file size");
+        return;
+    }
 
     blkconf_blocksizes(&n->conf);
     if (!blkconf_apply_backend_options(&n->conf, blk_is_read_only(n->conf.blk),