[PATCH v2] qga: Introduce NVMe disk bus type

[zhenwei pi <pizhenwei@bytedance.com>]

Assigning a NVMe disk by VFIO or emulating a NVMe controller by QEMU,
a NVMe disk get exposed in guest side. Support NVMe disk bus type and
implement posix version.

Test PCI passthrough case:
~#virsh qemu-agent-command buster '{"execute":"guest-get-disks"}' | jq
  ...
    {
      "name": "/dev/nvme0n1",
      "dependencies": [],
      "partition": false,
      "address": {
        "serial": "SAMSUNG MZQL23T8HCLS-00A07_S64HNE0N500076",
        "bus-type": "nvme",
        "bus": 0,
        "unit": 0,
        "pci-controller": {
          "bus": 0,
          "slot": 22,
          "domain": 0,
          "function": 0
        },
        "dev": "/dev/nvme0n1",
        "target": 0
      }
  ...

Signed-off-by: zhenwei pi <pizhenwei@bytedance.com>
---
 qga/commands-posix.c | 5 ++++-
 qga/qapi-schema.json | 3 ++-
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/qga/commands-posix.c b/qga/commands-posix.c
index 75dbaab68e..4ec83bbfbc 100644
--- a/qga/commands-posix.c
+++ b/qga/commands-posix.c
@@ -889,7 +889,8 @@ static bool build_guest_fsinfo_for_pci_dev(char const *syspath,
         if (driver && (g_str_equal(driver, "ata_piix") ||
                        g_str_equal(driver, "sym53c8xx") ||
                        g_str_equal(driver, "virtio-pci") ||
-                       g_str_equal(driver, "ahci"))) {
+                       g_str_equal(driver, "ahci") ||
+                       g_str_equal(driver, "nvme"))) {
             break;
         }
 
@@ -984,6 +985,8 @@ static bool build_guest_fsinfo_for_pci_dev(char const *syspath,
             g_debug("no host for '%s' (driver '%s')", syspath, driver);
             goto cleanup;
         }
+    } else if (strcmp(driver, "nvme") == 0) {
+        disk->bus_type = GUEST_DISK_BUS_TYPE_NVME;
     } else {
         g_debug("unknown driver '%s' (sysfs path '%s')", driver, syspath);
         goto cleanup;
diff --git a/qga/qapi-schema.json b/qga/qapi-schema.json
index 94e4aacdcc..8f73770210 100644
--- a/qga/qapi-schema.json
+++ b/qga/qapi-schema.json
@@ -827,13 +827,14 @@
 # @mmc: Win multimedia card (MMC) bus type
 # @virtual: Win virtual bus type
 # @file-backed-virtual: Win file-backed bus type
+# @nvme: NVMe disks (since 6.3)
 #
 # Since: 2.2; 'Unknown' and all entries below since 2.4
 ##
 { 'enum': 'GuestDiskBusType',
   'data': [ 'ide', 'fdc', 'scsi', 'virtio', 'xen', 'usb', 'uml', 'sata',
             'sd', 'unknown', 'ieee1394', 'ssa', 'fibre', 'raid', 'iscsi',
-            'sas', 'mmc', 'virtual', 'file-backed-virtual' ] }
+            'sas', 'mmc', 'virtual', 'file-backed-virtual', 'nvme' ] }
 
 
 ##
-- 
2.20.1