[PATCH v2 6/6] qapi: introduce CONFIG_READ event

2024-03-01 Thread Vladimir Sementsov-Ogievskiy
Send a new event when guest reads virtio-pci config after
virtio_notify_config() call.

That's useful to check that guest fetched modified config, for example
after resizing disk backend.

Signed-off-by: Vladimir Sementsov-Ogievskiy 
---
 hw/virtio/virtio-pci.c |  9 +
 include/monitor/qdev.h |  2 ++
 monitor/monitor.c  |  1 +
 qapi/qdev.json | 26 ++
 stubs/qdev.c   |  6 ++
 system/qdev-monitor.c  |  6 ++
 6 files changed, 50 insertions(+)

diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
index 1197341a3c..fab49a2410 100644
--- a/hw/virtio/virtio-pci.c
+++ b/hw/virtio/virtio-pci.c
@@ -23,6 +23,7 @@
 #include "hw/boards.h"
 #include "hw/virtio/virtio.h"
 #include "migration/qemu-file-types.h"
+#include "monitor/qdev.h"
 #include "hw/pci/pci.h"
 #include "hw/pci/pci_bus.h"
 #include "hw/qdev-properties.h"
@@ -530,6 +531,10 @@ static uint64_t virtio_pci_config_read(void *opaque, 
hwaddr addr,
 }
 addr -= config;
 
+if (vdev->generation > 0) {
+qdev_virtio_config_read_event(DEVICE(proxy));
+}
+
 switch (size) {
 case 1:
 val = virtio_config_readb(vdev, addr);
@@ -1735,6 +1740,10 @@ static uint64_t virtio_pci_device_read(void *opaque, 
hwaddr addr,
 return UINT64_MAX;
 }
 
+if (vdev->generation > 0) {
+qdev_virtio_config_read_event(DEVICE(proxy));
+}
+
 switch (size) {
 case 1:
 val = virtio_config_modern_readb(vdev, addr);
diff --git a/include/monitor/qdev.h b/include/monitor/qdev.h
index 1d57bf6577..fc9a834dca 100644
--- a/include/monitor/qdev.h
+++ b/include/monitor/qdev.h
@@ -36,4 +36,6 @@ DeviceState *qdev_device_add_from_qdict(const QDict *opts,
  */
 const char *qdev_set_id(DeviceState *dev, char *id, Error **errp);
 
+void qdev_virtio_config_read_event(DeviceState *dev);
+
 #endif
diff --git a/monitor/monitor.c b/monitor/monitor.c
index 01ede1babd..5b06146503 100644
--- a/monitor/monitor.c
+++ b/monitor/monitor.c
@@ -316,6 +316,7 @@ static MonitorQAPIEventConf 
monitor_qapi_event_conf[QAPI_EVENT__MAX] = {
 [QAPI_EVENT_VSERPORT_CHANGE]   = { 1000 * SCALE_MS },
 [QAPI_EVENT_MEMORY_DEVICE_SIZE_CHANGE] = { 1000 * SCALE_MS },
 [QAPI_EVENT_HV_BALLOON_STATUS_REPORT] = { 1000 * SCALE_MS },
+[QAPI_EVENT_VIRTIO_CONFIG_READ] = { 300 * SCALE_MS },
 };
 
 /*
diff --git a/qapi/qdev.json b/qapi/qdev.json
index 6ece164172..ffc5e3be18 100644
--- a/qapi/qdev.json
+++ b/qapi/qdev.json
@@ -179,3 +179,29 @@
 { 'command': 'device-sync-config',
   'features': [ 'unstable' ],
   'data': {'id': 'str'} }
+
+##
+# @VIRTIO_CONFIG_READ:
+#
+# Emitted whenever guest reads virtio device config after config change.
+#
+# @device: device name
+#
+# @path: device path
+#
+# Features:
+#
+# @unstable: The event is experimental.
+#
+# Since: 9.0
+#
+# Example:
+#
+# <- { "event": "VIRTIO_CONFIG_READ",
+#  "data": { "device": "virtio-net-pci-0",
+#"path": "/machine/peripheral/virtio-net-pci-0" },
+#  "timestamp": { "seconds": 1265044230, "microseconds": 450486 } }
+##
+{ 'event': 'VIRTIO_CONFIG_READ',
+  'features': [ 'unstable' ],
+  'data': { '*device': 'str', 'path': 'str' } }
diff --git a/stubs/qdev.c b/stubs/qdev.c
index 6869f6f90a..ab6c4afe0b 100644
--- a/stubs/qdev.c
+++ b/stubs/qdev.c
@@ -26,3 +26,9 @@ void qapi_event_send_device_unplug_guest_error(const char 
*device,
 {
 /* Nothing to do. */
 }
+
+void qapi_event_send_virtio_config_read(const char *device,
+const char *path)
+{
+/* Nothing to do. */
+}
diff --git a/system/qdev-monitor.c b/system/qdev-monitor.c
index b83b5d23c9..29b8242a2d 100644
--- a/system/qdev-monitor.c
+++ b/system/qdev-monitor.c
@@ -26,6 +26,7 @@
 #include "sysemu/runstate.h"
 #include "qapi/error.h"
 #include "qapi/qapi-commands-qdev.h"
+#include "qapi/qapi-events-qdev.h"
 #include "qapi/qmp/dispatch.h"
 #include "qapi/qmp/qdict.h"
 #include "qapi/qmp/qerror.h"
@@ -1206,3 +1207,8 @@ bool qmp_command_available(const QmpCommand *cmd, Error 
**errp)
 }
 return true;
 }
+
+void qdev_virtio_config_read_event(DeviceState *dev)
+{
+qapi_event_send_virtio_config_read(dev->id, dev->canonical_path);
+}
-- 
2.34.1




Re: [PATCH v2 6/6] qapi: introduce CONFIG_READ event

2024-03-07 Thread Markus Armbruster
Vladimir Sementsov-Ogievskiy  writes:

> Send a new event when guest reads virtio-pci config after
> virtio_notify_config() call.
>
> That's useful to check that guest fetched modified config, for example
> after resizing disk backend.
>
> Signed-off-by: Vladimir Sementsov-Ogievskiy 

[...]

> diff --git a/qapi/qdev.json b/qapi/qdev.json
> index 6ece164172..ffc5e3be18 100644
> --- a/qapi/qdev.json
> +++ b/qapi/qdev.json
> @@ -179,3 +179,29 @@
>  { 'command': 'device-sync-config',
>'features': [ 'unstable' ],
>'data': {'id': 'str'} }
> +
> +##
> +# @VIRTIO_CONFIG_READ:
> +#
> +# Emitted whenever guest reads virtio device config after config change.

Let's not abbreviate "configuration" to "config".

> +#
> +# @device: device name
> +#
> +# @path: device path
> +#
> +# Features:
> +#
> +# @unstable: The event is experimental.
> +#
> +# Since: 9.0
> +#
> +# Example:
> +#
> +# <- { "event": "VIRTIO_CONFIG_READ",
> +#  "data": { "device": "virtio-net-pci-0",
> +#"path": "/machine/peripheral/virtio-net-pci-0" },
> +#  "timestamp": { "seconds": 1265044230, "microseconds": 450486 } }
> +##

As for PATCH 4, I'd like to see some guidance on intended use.

> +{ 'event': 'VIRTIO_CONFIG_READ',
> +  'features': [ 'unstable' ],
> +  'data': { '*device': 'str', 'path': 'str' } }

[...]




Re: [PATCH v2 6/6] qapi: introduce CONFIG_READ event

2024-03-07 Thread Vladimir Sementsov-Ogievskiy

On 07.03.24 13:01, Markus Armbruster wrote:

Vladimir Sementsov-Ogievskiy  writes:


Send a new event when guest reads virtio-pci config after
virtio_notify_config() call.

That's useful to check that guest fetched modified config, for example
after resizing disk backend.

Signed-off-by: Vladimir Sementsov-Ogievskiy 


[...]


diff --git a/qapi/qdev.json b/qapi/qdev.json
index 6ece164172..ffc5e3be18 100644
--- a/qapi/qdev.json
+++ b/qapi/qdev.json
@@ -179,3 +179,29 @@
  { 'command': 'device-sync-config',
'features': [ 'unstable' ],
'data': {'id': 'str'} }
+
+##
+# @VIRTIO_CONFIG_READ:
+#
+# Emitted whenever guest reads virtio device config after config change.


Let's not abbreviate "configuration" to "config".


Oops, me again.




+#
+# @device: device name
+#
+# @path: device path
+#
+# Features:
+#
+# @unstable: The event is experimental.
+#
+# Since: 9.0
+#
+# Example:
+#
+# <- { "event": "VIRTIO_CONFIG_READ",
+#  "data": { "device": "virtio-net-pci-0",
+#"path": "/machine/peripheral/virtio-net-pci-0" },
+#  "timestamp": { "seconds": 1265044230, "microseconds": 450486 } }
+##


As for PATCH 4, I'd like to see some guidance on intended use.


Will do




+{ 'event': 'VIRTIO_CONFIG_READ',
+  'features': [ 'unstable' ],
+  'data': { '*device': 'str', 'path': 'str' } }


[...]



Thanks for reviewing my patches!

--
Best regards,
Vladimir