hw/block/nvme: support for shared namespace in subsystem

nvme-ns device is registered to a nvme controller device during the
initialization in nvme_register_namespace() in case that 'bus' property
is given which means it's mapped to a single controller.

This patch introduced a new property 'subsys' just like the controller
device instance did to map a namespace to a NVMe subsystem.

If 'subsys' property is given to the nvme-ns device, it will belong to
the specified subsystem and will be attached to all controllers in that
subsystem by enabling shared namespace capability in NMIC(Namespace
Multi-path I/O and Namespace Capabilities) in Identify Namespace.

Usage:

  -device nvme-subsys,id=subsys0
  -device nvme,serial=foo,id=nvme0,subsys=subsys0
  -device nvme,serial=bar,id=nvme1,subsys=subsys0
  -device nvme,serial=baz,id=nvme2,subsys=subsys0
  -device nvme-ns,id=ns1,drive=<drv>,nsid=1,subsys=subsys0  # Shared
  -device nvme-ns,id=ns2,drive=<drv>,nsid=2,bus=nvme2       # Non-shared

  In the above example, 'ns1' will be shared to 'nvme0' and 'nvme1' in
  the same subsystem.  On the other hand, 'ns2' will be attached to the
  'nvme2' only as a private namespace in that subsystem.

All the namespace with 'subsys' parameter will attach all controllers in
the subsystem to the namespace by default.

Signed-off-by: Minwoo Im <minwoo.im.dev@gmail.com>
Tested-by: Klaus Jensen <k.jensen@samsung.com>
Reviewed-by: Klaus Jensen <k.jensen@samsung.com>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Signed-off-by: Klaus Jensen <k.jensen@samsung.com>

1 files changed, 25 insertions, 0 deletions

diff --git a/hw/block/nvme-subsys.c b/hw/block/nvme-subsys.c
index 283a97b79d..af4804a819 100644
--- a/hw/block/nvme-subsys.c
+++ b/hw/block/nvme-subsys.c
@@ -43,6 +43,31 @@ int nvme_subsys_register_ctrl(NvmeCtrl *n, Error **errp)
     return cntlid;
 }
 
+int nvme_subsys_register_ns(NvmeNamespace *ns, Error **errp)
+{
+    NvmeSubsystem *subsys = ns->subsys;
+    NvmeCtrl *n;
+    int i;
+
+    if (subsys->namespaces[nvme_nsid(ns)]) {
+        error_setg(errp, "namespace %d already registerd to subsy %s",
+                   nvme_nsid(ns), subsys->parent_obj.id);
+        return -1;
+    }
+
+    subsys->namespaces[nvme_nsid(ns)] = ns;
+
+    for (i = 0; i < ARRAY_SIZE(subsys->ctrls); i++) {
+        n = subsys->ctrls[i];
+
+        if (n && nvme_register_namespace(n, ns, errp)) {
+            return -1;
+        }
+    }
+
+    return 0;
+}
+
 static void nvme_subsys_setup(NvmeSubsystem *subsys)
 {
     const char *nqn = subsys->params.nqn ?