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, 7 insertions, 0 deletions

diff --git a/hw/block/nvme-ns.h b/hw/block/nvme-ns.h
index 293ac990e3..929e788619 100644
--- a/hw/block/nvme-ns.h
+++ b/hw/block/nvme-ns.h
@@ -47,6 +47,8 @@ typedef struct NvmeNamespace {
     const uint32_t *iocs;
     uint8_t      csi;
 
+    NvmeSubsystem   *subsys;
+
     NvmeIdNsZoned   *id_ns_zoned;
     NvmeZone        *zone_array;
     QTAILQ_HEAD(, NvmeZone) exp_open_zones;
@@ -77,6 +79,11 @@ static inline uint32_t nvme_nsid(NvmeNamespace *ns)
     return -1;
 }
 
+static inline bool nvme_ns_shared(NvmeNamespace *ns)
+{
+    return !!ns->subsys;
+}
+
 static inline NvmeLBAF *nvme_ns_lbaf(NvmeNamespace *ns)
 {
     NvmeIdNs *id_ns = &ns->id_ns;