* [PATCH v4] net: vhost-user: add QAPI events to report connection state
@ 2025-02-17 9:25 Laurent Vivier
2025-02-18 7:50 ` Markus Armbruster
0 siblings, 1 reply; 3+ messages in thread
From: Laurent Vivier @ 2025-02-17 9:25 UTC (permalink / raw)
To: qemu-devel
Cc: Stefano Brivio, Marc-André Lureau, Jason Wang, Laine Stump,
Markus Armbruster, Eric Blake, Paolo Bonzini, Michael S. Tsirkin
The netdev reports NETDEV_VHOST_USER_CONNECTED event when
the chardev is connected, and NETDEV_VHOST_USER_DISCONNECTED
when it is disconnected.
The NETDEV_VHOST_USER_CONNECTED event includes the chardev id.
This allows a system manager like libvirt to detect when the server
fails.
For instance with passt:
{ 'execute': 'qmp_capabilities' }
{ "return": { } }
[killing passt here]
{ "timestamp": { "seconds": 1739538634, "microseconds": 920450 },
"event": "NETDEV_VHOST_USER_DISCONNECTED",
"data": { "netdev-id": "netdev0" } }
[automatic reconnection with reconnect-ms]
{ "timestamp": { "seconds": 1739538638, "microseconds": 354181 },
"event": "NETDEV_VHOST_USER_CONNECTED",
"data": { "netdev-id": "netdev0", "chardev-id": "chr0" } }
Tested-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: Laurent Vivier <lvivier@redhat.com>
---
Notes:
v4:
- as ChardevInfo is not needed, move events definition from
qapi/char.json to qapi/net.json
v3:
- remove ChardevInfo, provides only the chardev id
v2:
- remove duplicate line info.frontend_open
qapi/net.json | 40 ++++++++++++++++++++++++++++++++++++++++
net/vhost-user.c | 3 +++
2 files changed, 43 insertions(+)
diff --git a/qapi/net.json b/qapi/net.json
index 2739a2f42332..310cc4fd1907 100644
--- a/qapi/net.json
+++ b/qapi/net.json
@@ -1031,3 +1031,43 @@
##
{ 'event': 'NETDEV_STREAM_DISCONNECTED',
'data': { 'netdev-id': 'str' } }
+
+##
+# @NETDEV_VHOST_USER_CONNECTED:
+#
+# Emitted when the vhost-user chardev is connected
+#
+# @netdev-id: QEMU netdev id that is connected
+#
+# @chardev-id: The character device id used by the QEMU netdev
+#
+# Since: 10.0
+#
+# .. qmp-example::
+#
+# <- { "timestamp": {"seconds": 1739538638, "microseconds": 354181 },
+# "event": "NETDEV_VHOST_USER_CONNECTED",
+# "data": { "netdev-id": "netdev0", "chardev-id": "chr0" } }
+#
+##
+{ 'event': 'NETDEV_VHOST_USER_CONNECTED',
+ 'data': { 'netdev-id': 'str', 'chardev-id': 'str' } }
+
+##
+# @NETDEV_VHOST_USER_DISCONNECTED:
+#
+# Emitted when the vhost-user chardev is disconnected
+#
+# @netdev-id: QEMU netdev id that is disconnected
+#
+# Since: 10.0
+#
+# .. qmp-example::
+#
+# <- { "timestamp": { "seconds": 1739538634, "microseconds": 920450 },
+# "event": "NETDEV_VHOST_USER_DISCONNECTED",
+# "data": { "netdev-id": "netdev0" } }
+#
+##
+{ 'event': 'NETDEV_VHOST_USER_DISCONNECTED',
+ 'data': { 'netdev-id': 'str' } }
diff --git a/net/vhost-user.c b/net/vhost-user.c
index 12555518e838..0b235e50c650 100644
--- a/net/vhost-user.c
+++ b/net/vhost-user.c
@@ -16,6 +16,7 @@
#include "chardev/char-fe.h"
#include "qapi/error.h"
#include "qapi/qapi-commands-net.h"
+#include "qapi/qapi-events-net.h"
#include "qemu/config-file.h"
#include "qemu/error-report.h"
#include "qemu/option.h"
@@ -271,6 +272,7 @@ static void chr_closed_bh(void *opaque)
if (err) {
error_report_err(err);
}
+ qapi_event_send_netdev_vhost_user_disconnected(name);
}
static void net_vhost_user_event(void *opaque, QEMUChrEvent event)
@@ -300,6 +302,7 @@ static void net_vhost_user_event(void *opaque, QEMUChrEvent event)
net_vhost_user_watch, s);
qmp_set_link(name, true, &err);
s->started = true;
+ qapi_event_send_netdev_vhost_user_connected(name, chr->label);
break;
case CHR_EVENT_CLOSED:
/* a close event may happen during a read/write, but vhost
--
2.48.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH v4] net: vhost-user: add QAPI events to report connection state
2025-02-17 9:25 [PATCH v4] net: vhost-user: add QAPI events to report connection state Laurent Vivier
@ 2025-02-18 7:50 ` Markus Armbruster
2025-02-18 10:02 ` Laurent Vivier
0 siblings, 1 reply; 3+ messages in thread
From: Markus Armbruster @ 2025-02-18 7:50 UTC (permalink / raw)
To: Laurent Vivier
Cc: qemu-devel, Stefano Brivio, Marc-André Lureau, Jason Wang,
Laine Stump, Eric Blake, Paolo Bonzini, Michael S. Tsirkin
Laurent Vivier <lvivier@redhat.com> writes:
> The netdev reports NETDEV_VHOST_USER_CONNECTED event when
> the chardev is connected, and NETDEV_VHOST_USER_DISCONNECTED
> when it is disconnected.
>
> The NETDEV_VHOST_USER_CONNECTED event includes the chardev id.
>
> This allows a system manager like libvirt to detect when the server
> fails.
>
> For instance with passt:
>
> { 'execute': 'qmp_capabilities' }
> { "return": { } }
>
> [killing passt here]
>
> { "timestamp": { "seconds": 1739538634, "microseconds": 920450 },
> "event": "NETDEV_VHOST_USER_DISCONNECTED",
> "data": { "netdev-id": "netdev0" } }
>
> [automatic reconnection with reconnect-ms]
>
> { "timestamp": { "seconds": 1739538638, "microseconds": 354181 },
> "event": "NETDEV_VHOST_USER_CONNECTED",
> "data": { "netdev-id": "netdev0", "chardev-id": "chr0" } }
>
> Tested-by: Stefano Brivio <sbrivio@redhat.com>
> Signed-off-by: Laurent Vivier <lvivier@redhat.com>
> ---
>
> Notes:
> v4:
> - as ChardevInfo is not needed, move events definition from
> qapi/char.json to qapi/net.json
>
> v3:
> - remove ChardevInfo, provides only the chardev id
>
> v2:
> - remove duplicate line info.frontend_open
>
> qapi/net.json | 40 ++++++++++++++++++++++++++++++++++++++++
> net/vhost-user.c | 3 +++
> 2 files changed, 43 insertions(+)
>
> diff --git a/qapi/net.json b/qapi/net.json
> index 2739a2f42332..310cc4fd1907 100644
> --- a/qapi/net.json
> +++ b/qapi/net.json
> @@ -1031,3 +1031,43 @@
> ##
> { 'event': 'NETDEV_STREAM_DISCONNECTED',
> 'data': { 'netdev-id': 'str' } }
> +
> +##
> +# @NETDEV_VHOST_USER_CONNECTED:
> +#
> +# Emitted when the vhost-user chardev is connected
> +#
> +# @netdev-id: QEMU netdev id that is connected
> +#
> +# @chardev-id: The character device id used by the QEMU netdev
> +#
> +# Since: 10.0
> +#
> +# .. qmp-example::
> +#
> +# <- { "timestamp": {"seconds": 1739538638, "microseconds": 354181 },
> +# "event": "NETDEV_VHOST_USER_CONNECTED",
> +# "data": { "netdev-id": "netdev0", "chardev-id": "chr0" } }
> +#
> +##
> +{ 'event': 'NETDEV_VHOST_USER_CONNECTED',
> + 'data': { 'netdev-id': 'str', 'chardev-id': 'str' } }
> +
> +##
> +# @NETDEV_VHOST_USER_DISCONNECTED:
> +#
> +# Emitted when the vhost-user chardev is disconnected
> +#
> +# @netdev-id: QEMU netdev id that is disconnected
> +#
> +# Since: 10.0
> +#
> +# .. qmp-example::
> +#
> +# <- { "timestamp": { "seconds": 1739538634, "microseconds": 920450 },
> +# "event": "NETDEV_VHOST_USER_DISCONNECTED",
> +# "data": { "netdev-id": "netdev0" } }
> +#
> +##
> +{ 'event': 'NETDEV_VHOST_USER_DISCONNECTED',
> + 'data': { 'netdev-id': 'str' } }
> diff --git a/net/vhost-user.c b/net/vhost-user.c
> index 12555518e838..0b235e50c650 100644
> --- a/net/vhost-user.c
> +++ b/net/vhost-user.c
> @@ -16,6 +16,7 @@
> #include "chardev/char-fe.h"
> #include "qapi/error.h"
> #include "qapi/qapi-commands-net.h"
> +#include "qapi/qapi-events-net.h"
> #include "qemu/config-file.h"
> #include "qemu/error-report.h"
> #include "qemu/option.h"
> @@ -271,6 +272,7 @@ static void chr_closed_bh(void *opaque)
> if (err) {
> error_report_err(err);
> }
> + qapi_event_send_netdev_vhost_user_disconnected(name);
> }
>
> static void net_vhost_user_event(void *opaque, QEMUChrEvent event)
> @@ -300,6 +302,7 @@ static void net_vhost_user_event(void *opaque, QEMUChrEvent event)
> net_vhost_user_watch, s);
> qmp_set_link(name, true, &err);
> s->started = true;
> + qapi_event_send_netdev_vhost_user_connected(name, chr->label);
We seem to use "label" and "id" interchangeably. Unfortunate.
> break;
> case CHR_EVENT_CLOSED:
> /* a close event may happen during a read/write, but vhost
Like Daniel, I wonder whether provding events for chardevs instead would
be more broadly useful.
That said, there's nothing wrong with the patch itself, so
Acked-by: Markus Armbruster <armbru@redhat.com>
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH v4] net: vhost-user: add QAPI events to report connection state
2025-02-18 7:50 ` Markus Armbruster
@ 2025-02-18 10:02 ` Laurent Vivier
0 siblings, 0 replies; 3+ messages in thread
From: Laurent Vivier @ 2025-02-18 10:02 UTC (permalink / raw)
To: Markus Armbruster
Cc: qemu-devel, Stefano Brivio, Marc-André Lureau, Jason Wang,
Laine Stump, Eric Blake, Paolo Bonzini, Michael S. Tsirkin
On 18/02/2025 08:50, Markus Armbruster wrote:
> Laurent Vivier <lvivier@redhat.com> writes:
>
>> The netdev reports NETDEV_VHOST_USER_CONNECTED event when
>> the chardev is connected, and NETDEV_VHOST_USER_DISCONNECTED
>> when it is disconnected.
>>
>> The NETDEV_VHOST_USER_CONNECTED event includes the chardev id.
>>
>> This allows a system manager like libvirt to detect when the server
>> fails.
>>
>> For instance with passt:
>>
>> { 'execute': 'qmp_capabilities' }
>> { "return": { } }
>>
>> [killing passt here]
>>
>> { "timestamp": { "seconds": 1739538634, "microseconds": 920450 },
>> "event": "NETDEV_VHOST_USER_DISCONNECTED",
>> "data": { "netdev-id": "netdev0" } }
>>
>> [automatic reconnection with reconnect-ms]
>>
>> { "timestamp": { "seconds": 1739538638, "microseconds": 354181 },
>> "event": "NETDEV_VHOST_USER_CONNECTED",
>> "data": { "netdev-id": "netdev0", "chardev-id": "chr0" } }
>>
>> Tested-by: Stefano Brivio <sbrivio@redhat.com>
>> Signed-off-by: Laurent Vivier <lvivier@redhat.com>
>> ---
>>
>> Notes:
>> v4:
>> - as ChardevInfo is not needed, move events definition from
>> qapi/char.json to qapi/net.json
>>
>> v3:
>> - remove ChardevInfo, provides only the chardev id
>>
>> v2:
>> - remove duplicate line info.frontend_open
>>
>> qapi/net.json | 40 ++++++++++++++++++++++++++++++++++++++++
>> net/vhost-user.c | 3 +++
>> 2 files changed, 43 insertions(+)
>>
>> diff --git a/qapi/net.json b/qapi/net.json
>> index 2739a2f42332..310cc4fd1907 100644
>> --- a/qapi/net.json
>> +++ b/qapi/net.json
>> @@ -1031,3 +1031,43 @@
>> ##
>> { 'event': 'NETDEV_STREAM_DISCONNECTED',
>> 'data': { 'netdev-id': 'str' } }
>> +
>> +##
>> +# @NETDEV_VHOST_USER_CONNECTED:
>> +#
>> +# Emitted when the vhost-user chardev is connected
>> +#
>> +# @netdev-id: QEMU netdev id that is connected
>> +#
>> +# @chardev-id: The character device id used by the QEMU netdev
>> +#
>> +# Since: 10.0
>> +#
>> +# .. qmp-example::
>> +#
>> +# <- { "timestamp": {"seconds": 1739538638, "microseconds": 354181 },
>> +# "event": "NETDEV_VHOST_USER_CONNECTED",
>> +# "data": { "netdev-id": "netdev0", "chardev-id": "chr0" } }
>> +#
>> +##
>> +{ 'event': 'NETDEV_VHOST_USER_CONNECTED',
>> + 'data': { 'netdev-id': 'str', 'chardev-id': 'str' } }
>> +
>> +##
>> +# @NETDEV_VHOST_USER_DISCONNECTED:
>> +#
>> +# Emitted when the vhost-user chardev is disconnected
>> +#
>> +# @netdev-id: QEMU netdev id that is disconnected
>> +#
>> +# Since: 10.0
>> +#
>> +# .. qmp-example::
>> +#
>> +# <- { "timestamp": { "seconds": 1739538634, "microseconds": 920450 },
>> +# "event": "NETDEV_VHOST_USER_DISCONNECTED",
>> +# "data": { "netdev-id": "netdev0" } }
>> +#
>> +##
>> +{ 'event': 'NETDEV_VHOST_USER_DISCONNECTED',
>> + 'data': { 'netdev-id': 'str' } }
>> diff --git a/net/vhost-user.c b/net/vhost-user.c
>> index 12555518e838..0b235e50c650 100644
>> --- a/net/vhost-user.c
>> +++ b/net/vhost-user.c
>> @@ -16,6 +16,7 @@
>> #include "chardev/char-fe.h"
>> #include "qapi/error.h"
>> #include "qapi/qapi-commands-net.h"
>> +#include "qapi/qapi-events-net.h"
>> #include "qemu/config-file.h"
>> #include "qemu/error-report.h"
>> #include "qemu/option.h"
>> @@ -271,6 +272,7 @@ static void chr_closed_bh(void *opaque)
>> if (err) {
>> error_report_err(err);
>> }
>> + qapi_event_send_netdev_vhost_user_disconnected(name);
>> }
>>
>> static void net_vhost_user_event(void *opaque, QEMUChrEvent event)
>> @@ -300,6 +302,7 @@ static void net_vhost_user_event(void *opaque, QEMUChrEvent event)
>> net_vhost_user_watch, s);
>> qmp_set_link(name, true, &err);
>> s->started = true;
>> + qapi_event_send_netdev_vhost_user_connected(name, chr->label);
>
> We seem to use "label" and "id" interchangeably. Unfortunate.
>
>
>> break;
>> case CHR_EVENT_CLOSED:
>> /* a close event may happen during a read/write, but vhost
>
> Like Daniel, I wonder whether provding events for chardevs instead would
> be more broadly useful.
In fact, it depends on what libvirt needs or wants.
If we implement the event for chardev, libvirt will have to find internally which netdev
it belongs to, if we implement the event for netdev it has directly the netdev id.
But no one never asked for a chardev event until now, not sure it's useful.
Stefano shown that vhost-user event is really easy to use with existing code of libvirt.
>
> That said, there's nothing wrong with the patch itself, so
> Acked-by: Markus Armbruster <armbru@redhat.com>
>
Thanks,
Laurent
^ permalink raw reply [flat|nested] 3+ messages in thread
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2025-02-17 9:25 [PATCH v4] net: vhost-user: add QAPI events to report connection state Laurent Vivier
2025-02-18 7:50 ` Markus Armbruster
2025-02-18 10:02 ` Laurent Vivier
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