hw/block/nvme: introduce nvme-subsys device

To support multi-path in QEMU NVMe device model, We need to have NVMe
subsystem hierarchy to map controllers and namespaces to a NVMe
subsystem.

This patch introduced a simple nvme-subsys device model.  The subsystem
will be prepared with subsystem NQN with <subsys_id> provided in
nvme-subsys device:

  ex) -device nvme-subsys,id=subsys0: nqn.2019-08.org.qemu:subsys0

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>
[k.jensen: added 'nqn' device parameter per request]
Signed-off-by: Klaus Jensen <k.jensen@samsung.com>

1 files changed, 70 insertions, 0 deletions

diff --git a/hw/block/nvme-subsys.c b/hw/block/nvme-subsys.c
new file mode 100644
index 0000000000..840448bb13
--- /dev/null
+++ b/hw/block/nvme-subsys.c
@@ -0,0 +1,70 @@
+/*
+ * QEMU NVM Express Subsystem: nvme-subsys
+ *
+ * Copyright (c) 2021 Minwoo Im <minwoo.im.dev@gmail.com>
+ *
+ * This code is licensed under the GNU GPL v2.  Refer COPYING.
+ */
+
+#include "qemu/units.h"
+#include "qemu/osdep.h"
+#include "qemu/uuid.h"
+#include "qemu/iov.h"
+#include "qemu/cutils.h"
+#include "qapi/error.h"
+#include "hw/qdev-properties.h"
+#include "hw/qdev-core.h"
+#include "hw/block/block.h"
+#include "block/aio.h"
+#include "block/accounting.h"
+#include "sysemu/sysemu.h"
+#include "hw/pci/pci.h"
+#include "nvme.h"
+#include "nvme-subsys.h"
+
+static void nvme_subsys_setup(NvmeSubsystem *subsys)
+{
+    const char *nqn = subsys->params.nqn ?
+        subsys->params.nqn : subsys->parent_obj.id;
+
+    snprintf((char *)subsys->subnqn, sizeof(subsys->subnqn),
+             "nqn.2019-08.org.qemu:%s", nqn);
+}
+
+static void nvme_subsys_realize(DeviceState *dev, Error **errp)
+{
+    NvmeSubsystem *subsys = NVME_SUBSYS(dev);
+
+    nvme_subsys_setup(subsys);
+}
+
+static Property nvme_subsystem_props[] = {
+    DEFINE_PROP_STRING("nqn", NvmeSubsystem, params.nqn),
+    DEFINE_PROP_END_OF_LIST(),
+};
+
+static void nvme_subsys_class_init(ObjectClass *oc, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(oc);
+
+    set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
+
+    dc->realize = nvme_subsys_realize;
+    dc->desc = "Virtual NVMe subsystem";
+
+    device_class_set_props(dc, nvme_subsystem_props);
+}
+
+static const TypeInfo nvme_subsys_info = {
+    .name = TYPE_NVME_SUBSYS,
+    .parent = TYPE_DEVICE,
+    .class_init = nvme_subsys_class_init,
+    .instance_size = sizeof(NvmeSubsystem),
+};
+
+static void nvme_subsys_register_types(void)
+{
+    type_register_static(&nvme_subsys_info);
+}
+
+type_init(nvme_subsys_register_types)