Introduce a test, that checks that plug/unplug of virtio-blk device
works.

(the test is developed by copying hotplug_cpu.py, so keep original
copyright)

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
---
 tests/avocado/hotplug_blk.py | 69 ++++++++++++++++++++++++++++++++++++
 1 file changed, 69 insertions(+)
 create mode 100644 tests/avocado/hotplug_blk.py

diff --git a/tests/avocado/hotplug_blk.py b/tests/avocado/hotplug_blk.py
new file mode 100644
index 0000000000..5dc30f6616
--- /dev/null
+++ b/tests/avocado/hotplug_blk.py
@@ -0,0 +1,69 @@
+# Functional test that hotplugs a virtio blk disk and checks it on a Linux
+# guest
+#
+# Copyright (c) 2021 Red Hat, Inc.
+# Copyright (c) Yandex
+#
+# This work is licensed under the terms of the GNU GPL, version 2 or
+# later.  See the COPYING file in the top-level directory.
+
+import time
+
+from avocado_qemu import LinuxTest
+
+
+class HotPlug(LinuxTest):
+    def blockdev_add(self) -> None:
+        self.vm.cmd('blockdev-add', **{
+            'driver': 'null-co',
+            'size': 1073741824,
+            'node-name': 'disk'
+        })
+
+    def assert_vda(self) -> None:
+        self.ssh_command('test -e /sys/block/vda')
+
+    def assert_no_vda(self) -> None:
+        with self.assertRaises(AssertionError):
+            self.assert_vda()
+
+    def plug(self) -> None:
+        args = {
+            'driver': 'virtio-blk-pci',
+            'drive': 'disk',
+            'id': 'virtio-disk0',
+            'bus': 'pci.1',
+            'addr': 1
+        }
+
+        self.assert_no_vda()
+        self.vm.cmd('device_add', args)
+        try:
+            self.assert_vda()
+        except AssertionError:
+            time.sleep(1)
+            self.assert_vda()
+
+    def unplug(self) -> None:
+        self.vm.cmd('device_del', id='virtio-disk0')
+
+        self.vm.event_wait('DEVICE_DELETED', 1.0,
+                           match={'data': {'device': 'virtio-disk0'}})
+
+        self.assert_no_vda()
+
+    def test(self) -> None:
+        """
+        :avocado: tags=arch:x86_64
+        :avocado: tags=machine:q35
+        :avocado: tags=accel:kvm
+        """
+        self.require_accelerator('kvm')
+        self.vm.add_args('-accel', 'kvm')
+        self.vm.add_args('-device', 'pcie-pci-bridge,id=pci.1,bus=pcie.0')
+
+        self.launch_and_wait()
+        self.blockdev_add()
+
+        self.plug()
+        self.unplug()
-- 
2.34.1

ping!)

-- 
Best regards,
Vladimir