hw/nvme: enforce common serial per subsystem

The Identify Controller Serial Number (SN) is the serial number for the
NVM subsystem and must be the same across all controller in the NVM
subsystem.

Enforce this.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Signed-off-by: Klaus Jensen <k.jensen@samsung.com>

hw/nvme/nvme.h

@@ -48,6 +48,7 @@ typedef struct NvmeSubsystem {
     DeviceState parent_obj;
     NvmeBus     bus;
     uint8_t     subnqn[256];
+    char        *serial;
 
     NvmeCtrl      *ctrls[NVME_MAX_CONTROLLERS];
     NvmeNamespace *namespaces[NVME_MAX_NAMESPACES + 1];

hw/nvme/subsys.c

@@ -27,6 +27,13 @@ int nvme_subsys_register_ctrl(NvmeCtrl *n, Error **errp)
         return -1;
     }
 
+    if (!subsys->serial) {
+        subsys->serial = g_strdup(n->params.serial);
+    } else if (strcmp(subsys->serial, n->params.serial)) {
+        error_setg(errp, "invalid controller serial");
+        return -1;
+    }
+
     subsys->ctrls[cntlid] = n;
 
     for (nsid = 1; nsid < ARRAY_SIZE(subsys->namespaces); nsid++) {