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, 14 insertions, 3 deletions

diff --git a/hw/block/nvme-ns.c b/hw/block/nvme-ns.c
index 93ac6e1..64b6a49 100644
--- a/hw/block/nvme-ns.c
+++ b/hw/block/nvme-ns.c
@@ -63,6 +63,10 @@ static int nvme_ns_init(NvmeNamespace *ns, Error **errp)
 
     id_ns->npda = id_ns->npdg = npdg - 1;
 
+    if (nvme_ns_shared(ns)) {
+        id_ns->nmic |= NVME_NMIC_NS_SHARED;
+    }
+
     return 0;
 }
 
@@ -363,14 +367,21 @@ static void nvme_ns_realize(DeviceState *dev, Error **errp)
         return;
     }
 
-    if (nvme_register_namespace(n, ns, errp)) {
-        return;
+    if (ns->subsys) {
+        if (nvme_subsys_register_ns(ns, errp)) {
+            return;
+        }
+    } else {
+        if (nvme_register_namespace(n, ns, errp)) {
+            return;
+        }
     }
-
 }
 
 static Property nvme_ns_props[] = {
     DEFINE_BLOCK_PROPERTIES(NvmeNamespace, blkconf),
+    DEFINE_PROP_LINK("subsys", NvmeNamespace, subsys, TYPE_NVME_SUBSYS,
+                     NvmeSubsystem *),
     DEFINE_PROP_UINT32("nsid", NvmeNamespace, params.nsid, 0),
     DEFINE_PROP_UUID("uuid", NvmeNamespace, params.uuid),
     DEFINE_PROP_BOOL("zoned", NvmeNamespace, params.zoned, false),