From: Xuan Zhuo <xuanzhuo@linux.alibaba.com>

virtio-net implements queue reset. Queued packets in the corresponding
queue pair are flushed or purged.

Queue reset is currently only implemented for non-vhosts.

Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
---
 hw/net/virtio-net.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
index 7ad948ee7c..8396e21a67 100644
--- a/hw/net/virtio-net.c
+++ b/hw/net/virtio-net.c
@@ -531,6 +531,19 @@ static RxFilterInfo *virtio_net_query_rxfilter(NetClientState *nc)
     return info;
 }
 
+static void virtio_net_queue_reset(VirtIODevice *vdev, uint32_t queue_index)
+{
+    VirtIONet *n = VIRTIO_NET(vdev);
+    NetClientState *nc = qemu_get_subqueue(n->nic, vq2q(queue_index));
+
+    if (!nc->peer) {
+        return;
+    }
+
+    qemu_flush_or_purge_queued_packets(nc->peer, true);
+    assert(!virtio_net_get_subqueue(nc)->async_tx.elem);
+}
+
 static void virtio_net_reset(VirtIODevice *vdev)
 {
     VirtIONet *n = VIRTIO_NET(vdev);
@@ -741,6 +754,7 @@ static uint64_t virtio_net_get_features(VirtIODevice *vdev, uint64_t features,
     }
 
     if (!get_vhost_net(nc->peer)) {
+        virtio_add_feature(&features, VIRTIO_F_RING_RESET);
         return features;
     }
 
@@ -3766,6 +3780,7 @@ static void virtio_net_class_init(ObjectClass *klass, void *data)
     vdc->set_features = virtio_net_set_features;
     vdc->bad_features = virtio_net_bad_features;
     vdc->reset = virtio_net_reset;
+    vdc->queue_reset = virtio_net_queue_reset;
     vdc->set_status = virtio_net_set_status;
     vdc->guest_notifier_mask = virtio_net_guest_notifier_mask;
     vdc->guest_notifier_pending = virtio_net_guest_notifier_pending;
-- 
2.32.0

在 2022/7/18 19:17, Kangjie Xu 写道:
> From: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
>
> virtio-net implements queue reset. Queued packets in the corresponding
> queue pair are flushed or purged.
>
> Queue reset is currently only implemented for non-vhosts.
>
> Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
> ---
>   hw/net/virtio-net.c | 15 +++++++++++++++
>   1 file changed, 15 insertions(+)
>
> diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
> index 7ad948ee7c..8396e21a67 100644
> --- a/hw/net/virtio-net.c
> +++ b/hw/net/virtio-net.c
> @@ -531,6 +531,19 @@ static RxFilterInfo *virtio_net_query_rxfilter(NetClientState *nc)
>       return info;
>   }
>   
> +static void virtio_net_queue_reset(VirtIODevice *vdev, uint32_t queue_index)
> +{
> +    VirtIONet *n = VIRTIO_NET(vdev);
> +    NetClientState *nc = qemu_get_subqueue(n->nic, vq2q(queue_index));
> +
> +    if (!nc->peer) {
> +        return;
> +    }
> +
> +    qemu_flush_or_purge_queued_packets(nc->peer, true);
> +    assert(!virtio_net_get_subqueue(nc)->async_tx.elem);


Let's try to reuse this function in virtio_net_reset().


> +}
> +
>   static void virtio_net_reset(VirtIODevice *vdev)
>   {
>       VirtIONet *n = VIRTIO_NET(vdev);
> @@ -741,6 +754,7 @@ static uint64_t virtio_net_get_features(VirtIODevice *vdev, uint64_t features,
>       }
>   
>       if (!get_vhost_net(nc->peer)) {
> +        virtio_add_feature(&features, VIRTIO_F_RING_RESET);


This breaks migration compatibility.

We probably need:

1) a new command line parameter
2) make it disabled for pre-7.2 machine

Thanks


>           return features;
>       }
>   
> @@ -3766,6 +3780,7 @@ static void virtio_net_class_init(ObjectClass *klass, void *data)
>       vdc->set_features = virtio_net_set_features;
>       vdc->bad_features = virtio_net_bad_features;
>       vdc->reset = virtio_net_reset;
> +    vdc->queue_reset = virtio_net_queue_reset;
>       vdc->set_status = virtio_net_set_status;
>       vdc->guest_notifier_mask = virtio_net_guest_notifier_mask;
>       vdc->guest_notifier_pending = virtio_net_guest_notifier_pending;

在 2022/7/26 11:43, Jason Wang 写道:
>
> 在 2022/7/18 19:17, Kangjie Xu 写道:
>> From: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
>>
>> virtio-net implements queue reset. Queued packets in the corresponding
>> queue pair are flushed or purged.
>>
>> Queue reset is currently only implemented for non-vhosts.
>>
>> Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
>> ---
>>   hw/net/virtio-net.c | 15 +++++++++++++++
>>   1 file changed, 15 insertions(+)
>>
>> diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
>> index 7ad948ee7c..8396e21a67 100644
>> --- a/hw/net/virtio-net.c
>> +++ b/hw/net/virtio-net.c
>> @@ -531,6 +531,19 @@ static RxFilterInfo 
>> *virtio_net_query_rxfilter(NetClientState *nc)
>>       return info;
>>   }
>>   +static void virtio_net_queue_reset(VirtIODevice *vdev, uint32_t 
>> queue_index)
>> +{
>> +    VirtIONet *n = VIRTIO_NET(vdev);
>> +    NetClientState *nc = qemu_get_subqueue(n->nic, vq2q(queue_index));
>> +
>> +    if (!nc->peer) {
>> +        return;
>> +    }
>> +
>> +    qemu_flush_or_purge_queued_packets(nc->peer, true);
>> +    assert(!virtio_net_get_subqueue(nc)->async_tx.elem);
>
>
> Let's try to reuse this function in virtio_net_reset().
>
Yeah, I'll fix it.

Thanks.

>
>> +}
>> +
>>   static void virtio_net_reset(VirtIODevice *vdev)
>>   {
>>       VirtIONet *n = VIRTIO_NET(vdev);
>> @@ -741,6 +754,7 @@ static uint64_t 
>> virtio_net_get_features(VirtIODevice *vdev, uint64_t features,
>>       }
>>         if (!get_vhost_net(nc->peer)) {
>> +        virtio_add_feature(&features, VIRTIO_F_RING_RESET);
>
>
> This breaks migration compatibility.
>
> We probably need:
>
> 1) a new command line parameter
> 2) make it disabled for pre-7.2 machine
>
> Thanks
>
>
Sorry, I don't get what is the meaning of "pre-7.2 machine". Could you 
please explain it?

Thanks

>>           return features;
>>       }
>>   @@ -3766,6 +3780,7 @@ static void virtio_net_class_init(ObjectClass 
>> *klass, void *data)
>>       vdc->set_features = virtio_net_set_features;
>>       vdc->bad_features = virtio_net_bad_features;
>>       vdc->reset = virtio_net_reset;
>> +    vdc->queue_reset = virtio_net_queue_reset;
>>       vdc->set_status = virtio_net_set_status;
>>       vdc->guest_notifier_mask = virtio_net_guest_notifier_mask;
>>       vdc->guest_notifier_pending = virtio_net_guest_notifier_pending;

On Tue, Jul 26, 2022 at 3:02 PM Kangjie Xu <kangjie.xu@linux.alibaba.com> wrote:
>
>
> 在 2022/7/26 11:43, Jason Wang 写道:
> >
> > 在 2022/7/18 19:17, Kangjie Xu 写道:
> >> From: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
> >>
> >> virtio-net implements queue reset. Queued packets in the corresponding
> >> queue pair are flushed or purged.
> >>
> >> Queue reset is currently only implemented for non-vhosts.
> >>
> >> Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
> >> ---
> >>   hw/net/virtio-net.c | 15 +++++++++++++++
> >>   1 file changed, 15 insertions(+)
> >>
> >> diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
> >> index 7ad948ee7c..8396e21a67 100644
> >> --- a/hw/net/virtio-net.c
> >> +++ b/hw/net/virtio-net.c
> >> @@ -531,6 +531,19 @@ static RxFilterInfo
> >> *virtio_net_query_rxfilter(NetClientState *nc)
> >>       return info;
> >>   }
> >>   +static void virtio_net_queue_reset(VirtIODevice *vdev, uint32_t
> >> queue_index)
> >> +{
> >> +    VirtIONet *n = VIRTIO_NET(vdev);
> >> +    NetClientState *nc = qemu_get_subqueue(n->nic, vq2q(queue_index));
> >> +
> >> +    if (!nc->peer) {
> >> +        return;
> >> +    }
> >> +
> >> +    qemu_flush_or_purge_queued_packets(nc->peer, true);
> >> +    assert(!virtio_net_get_subqueue(nc)->async_tx.elem);
> >
> >
> > Let's try to reuse this function in virtio_net_reset().
> >
> Yeah, I'll fix it.
>
> Thanks.
>
> >
> >> +}
> >> +
> >>   static void virtio_net_reset(VirtIODevice *vdev)
> >>   {
> >>       VirtIONet *n = VIRTIO_NET(vdev);
> >> @@ -741,6 +754,7 @@ static uint64_t
> >> virtio_net_get_features(VirtIODevice *vdev, uint64_t features,
> >>       }
> >>         if (!get_vhost_net(nc->peer)) {
> >> +        virtio_add_feature(&features, VIRTIO_F_RING_RESET);
> >
> >
> > This breaks migration compatibility.
> >
> > We probably need:
> >
> > 1) a new command line parameter
> > 2) make it disabled for pre-7.2 machine
> >
> > Thanks
> >
> >
> Sorry, I don't get what is the meaning of "pre-7.2 machine". Could you
> please explain it?

I meant for pre 7.2 machine type, we should make reset fault off by default.

Otherwise we break migration compatibility.

Thanks

>
> Thanks
>
> >>           return features;
> >>       }
> >>   @@ -3766,6 +3780,7 @@ static void virtio_net_class_init(ObjectClass
> >> *klass, void *data)
> >>       vdc->set_features = virtio_net_set_features;
> >>       vdc->bad_features = virtio_net_bad_features;
> >>       vdc->reset = virtio_net_reset;
> >> +    vdc->queue_reset = virtio_net_queue_reset;
> >>       vdc->set_status = virtio_net_set_status;
> >>       vdc->guest_notifier_mask = virtio_net_guest_notifier_mask;
> >>       vdc->guest_notifier_pending = virtio_net_guest_notifier_pending;
>

在 2022/7/27 13:00, Jason Wang 写道:
> On Tue, Jul 26, 2022 at 3:02 PM Kangjie Xu <kangjie.xu@linux.alibaba.com> wrote:
>>
>> 在 2022/7/26 11:43, Jason Wang 写道:
>>> 在 2022/7/18 19:17, Kangjie Xu 写道:
>>>> From: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
>>>>
>>>> virtio-net implements queue reset. Queued packets in the corresponding
>>>> queue pair are flushed or purged.
>>>>
>>>> Queue reset is currently only implemented for non-vhosts.
>>>>
>>>> Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
>>>> ---
>>>>    hw/net/virtio-net.c | 15 +++++++++++++++
>>>>    1 file changed, 15 insertions(+)
>>>>
>>>> diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
>>>> index 7ad948ee7c..8396e21a67 100644
>>>> --- a/hw/net/virtio-net.c
>>>> +++ b/hw/net/virtio-net.c
>>>> @@ -531,6 +531,19 @@ static RxFilterInfo
>>>> *virtio_net_query_rxfilter(NetClientState *nc)
>>>>        return info;
>>>>    }
>>>>    +static void virtio_net_queue_reset(VirtIODevice *vdev, uint32_t
>>>> queue_index)
>>>> +{
>>>> +    VirtIONet *n = VIRTIO_NET(vdev);
>>>> +    NetClientState *nc = qemu_get_subqueue(n->nic, vq2q(queue_index));
>>>> +
>>>> +    if (!nc->peer) {
>>>> +        return;
>>>> +    }
>>>> +
>>>> +    qemu_flush_or_purge_queued_packets(nc->peer, true);
>>>> +    assert(!virtio_net_get_subqueue(nc)->async_tx.elem);
>>>
>>> Let's try to reuse this function in virtio_net_reset().
>>>
>> Yeah, I'll fix it.
>>
>> Thanks.
>>
>>>> +}
>>>> +
>>>>    static void virtio_net_reset(VirtIODevice *vdev)
>>>>    {
>>>>        VirtIONet *n = VIRTIO_NET(vdev);
>>>> @@ -741,6 +754,7 @@ static uint64_t
>>>> virtio_net_get_features(VirtIODevice *vdev, uint64_t features,
>>>>        }
>>>>          if (!get_vhost_net(nc->peer)) {
>>>> +        virtio_add_feature(&features, VIRTIO_F_RING_RESET);
>>>
>>> This breaks migration compatibility.
>>>
>>> We probably need:
>>>
>>> 1) a new command line parameter
>>> 2) make it disabled for pre-7.2 machine
>>>
>>> Thanks
>>>
>>>
>> Sorry, I don't get what is the meaning of "pre-7.2 machine". Could you
>> please explain it?
> I meant for pre 7.2 machine type, we should make reset fault off by default.
>
> Otherwise we break migration compatibility.
>
> Thanks

Sorry, I did not express myself clearly. Is "7.2" the version of a 
system or a module? If it is a system version, what is the system?

I did not have backgrond knowledge related to this part and will 
investigate migration issues afterwards.

Thanks.

>> Thanks
>>
>>>>            return features;
>>>>        }
>>>>    @@ -3766,6 +3780,7 @@ static void virtio_net_class_init(ObjectClass
>>>> *klass, void *data)
>>>>        vdc->set_features = virtio_net_set_features;
>>>>        vdc->bad_features = virtio_net_bad_features;
>>>>        vdc->reset = virtio_net_reset;
>>>> +    vdc->queue_reset = virtio_net_queue_reset;
>>>>        vdc->set_status = virtio_net_set_status;
>>>>        vdc->guest_notifier_mask = virtio_net_guest_notifier_mask;
>>>>        vdc->guest_notifier_pending = virtio_net_guest_notifier_pending;

On Wed, Jul 27, 2022 at 2:25 PM Kangjie Xu <kangjie.xu@linux.alibaba.com> wrote:
>
>
> 在 2022/7/27 13:00, Jason Wang 写道:
> > On Tue, Jul 26, 2022 at 3:02 PM Kangjie Xu <kangjie.xu@linux.alibaba.com> wrote:
> >>
> >> 在 2022/7/26 11:43, Jason Wang 写道:
> >>> 在 2022/7/18 19:17, Kangjie Xu 写道:
> >>>> From: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
> >>>>
> >>>> virtio-net implements queue reset. Queued packets in the corresponding
> >>>> queue pair are flushed or purged.
> >>>>
> >>>> Queue reset is currently only implemented for non-vhosts.
> >>>>
> >>>> Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
> >>>> ---
> >>>>    hw/net/virtio-net.c | 15 +++++++++++++++
> >>>>    1 file changed, 15 insertions(+)
> >>>>
> >>>> diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
> >>>> index 7ad948ee7c..8396e21a67 100644
> >>>> --- a/hw/net/virtio-net.c
> >>>> +++ b/hw/net/virtio-net.c
> >>>> @@ -531,6 +531,19 @@ static RxFilterInfo
> >>>> *virtio_net_query_rxfilter(NetClientState *nc)
> >>>>        return info;
> >>>>    }
> >>>>    +static void virtio_net_queue_reset(VirtIODevice *vdev, uint32_t
> >>>> queue_index)
> >>>> +{
> >>>> +    VirtIONet *n = VIRTIO_NET(vdev);
> >>>> +    NetClientState *nc = qemu_get_subqueue(n->nic, vq2q(queue_index));
> >>>> +
> >>>> +    if (!nc->peer) {
> >>>> +        return;
> >>>> +    }
> >>>> +
> >>>> +    qemu_flush_or_purge_queued_packets(nc->peer, true);
> >>>> +    assert(!virtio_net_get_subqueue(nc)->async_tx.elem);
> >>>
> >>> Let's try to reuse this function in virtio_net_reset().
> >>>
> >> Yeah, I'll fix it.
> >>
> >> Thanks.
> >>
> >>>> +}
> >>>> +
> >>>>    static void virtio_net_reset(VirtIODevice *vdev)
> >>>>    {
> >>>>        VirtIONet *n = VIRTIO_NET(vdev);
> >>>> @@ -741,6 +754,7 @@ static uint64_t
> >>>> virtio_net_get_features(VirtIODevice *vdev, uint64_t features,
> >>>>        }
> >>>>          if (!get_vhost_net(nc->peer)) {
> >>>> +        virtio_add_feature(&features, VIRTIO_F_RING_RESET);
> >>>
> >>> This breaks migration compatibility.
> >>>
> >>> We probably need:
> >>>
> >>> 1) a new command line parameter
> >>> 2) make it disabled for pre-7.2 machine
> >>>
> >>> Thanks
> >>>
> >>>
> >> Sorry, I don't get what is the meaning of "pre-7.2 machine". Could you
> >> please explain it?
> > I meant for pre 7.2 machine type, we should make reset fault off by default.
> >
> > Otherwise we break migration compatibility.
> >
> > Thanks
>
> Sorry, I did not express myself clearly. Is "7.2" the version of a
> system or a module? If it is a system version, what is the system?

It's the machine type to make sure the migration can work. (you can
get the list of those types via qemu -machine ?)

E.g you can start a 7.0 machine on Qemu 7.1 and it guarantees to be
migrated to 7.0 machine on Qemu 7.0.

>
> I did not have backgrond knowledge related to this part and will
> investigate migration issues afterwards.

Git grep hw_compat_7_0 may give you more hints.

Thanks

>
> Thanks.
>
> >> Thanks
> >>
> >>>>            return features;
> >>>>        }
> >>>>    @@ -3766,6 +3780,7 @@ static void virtio_net_class_init(ObjectClass
> >>>> *klass, void *data)
> >>>>        vdc->set_features = virtio_net_set_features;
> >>>>        vdc->bad_features = virtio_net_bad_features;
> >>>>        vdc->reset = virtio_net_reset;
> >>>> +    vdc->queue_reset = virtio_net_queue_reset;
> >>>>        vdc->set_status = virtio_net_set_status;
> >>>>        vdc->guest_notifier_mask = virtio_net_guest_notifier_mask;
> >>>>        vdc->guest_notifier_pending = virtio_net_guest_notifier_pending;
>

在 2022/7/27 14:59, Jason Wang 写道:
> On Wed, Jul 27, 2022 at 2:25 PM Kangjie Xu <kangjie.xu@linux.alibaba.com> wrote:
>>
>> 在 2022/7/27 13:00, Jason Wang 写道:
>>> On Tue, Jul 26, 2022 at 3:02 PM Kangjie Xu <kangjie.xu@linux.alibaba.com> wrote:
>>>> 在 2022/7/26 11:43, Jason Wang 写道:
>>>>> 在 2022/7/18 19:17, Kangjie Xu 写道:
>>>>>> From: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
>>>>>>
>>>>>> virtio-net implements queue reset. Queued packets in the corresponding
>>>>>> queue pair are flushed or purged.
>>>>>>
>>>>>> Queue reset is currently only implemented for non-vhosts.
>>>>>>
>>>>>> Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
>>>>>> ---
>>>>>>     hw/net/virtio-net.c | 15 +++++++++++++++
>>>>>>     1 file changed, 15 insertions(+)
>>>>>>
>>>>>> diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
>>>>>> index 7ad948ee7c..8396e21a67 100644
>>>>>> --- a/hw/net/virtio-net.c
>>>>>> +++ b/hw/net/virtio-net.c
>>>>>> @@ -531,6 +531,19 @@ static RxFilterInfo
>>>>>> *virtio_net_query_rxfilter(NetClientState *nc)
>>>>>>         return info;
>>>>>>     }
>>>>>>     +static void virtio_net_queue_reset(VirtIODevice *vdev, uint32_t
>>>>>> queue_index)
>>>>>> +{
>>>>>> +    VirtIONet *n = VIRTIO_NET(vdev);
>>>>>> +    NetClientState *nc = qemu_get_subqueue(n->nic, vq2q(queue_index));
>>>>>> +
>>>>>> +    if (!nc->peer) {
>>>>>> +        return;
>>>>>> +    }
>>>>>> +
>>>>>> +    qemu_flush_or_purge_queued_packets(nc->peer, true);
>>>>>> +    assert(!virtio_net_get_subqueue(nc)->async_tx.elem);
>>>>> Let's try to reuse this function in virtio_net_reset().
>>>>>
>>>> Yeah, I'll fix it.
>>>>
>>>> Thanks.
>>>>
>>>>>> +}
>>>>>> +
>>>>>>     static void virtio_net_reset(VirtIODevice *vdev)
>>>>>>     {
>>>>>>         VirtIONet *n = VIRTIO_NET(vdev);
>>>>>> @@ -741,6 +754,7 @@ static uint64_t
>>>>>> virtio_net_get_features(VirtIODevice *vdev, uint64_t features,
>>>>>>         }
>>>>>>           if (!get_vhost_net(nc->peer)) {
>>>>>> +        virtio_add_feature(&features, VIRTIO_F_RING_RESET);
>>>>> This breaks migration compatibility.
>>>>>
>>>>> We probably need:
>>>>>
>>>>> 1) a new command line parameter
>>>>> 2) make it disabled for pre-7.2 machine
>>>>>
>>>>> Thanks
>>>>>
>>>>>
>>>> Sorry, I don't get what is the meaning of "pre-7.2 machine". Could you
>>>> please explain it?
>>> I meant for pre 7.2 machine type, we should make reset fault off by default.
>>>
>>> Otherwise we break migration compatibility.
>>>
>>> Thanks
>> Sorry, I did not express myself clearly. Is "7.2" the version of a
>> system or a module? If it is a system version, what is the system?
> It's the machine type to make sure the migration can work. (you can
> get the list of those types via qemu -machine ?)
>
> E.g you can start a 7.0 machine on Qemu 7.1 and it guarantees to be
> migrated to 7.0 machine on Qemu 7.0.
>
>> I did not have backgrond knowledge related to this part and will
>> investigate migration issues afterwards.
> Git grep hw_compat_7_0 may give you more hints.
>
> Thanks

Okay, I get it.

Thanks for your guidelines.


>
>> Thanks.
>>
>>>> Thanks
>>>>
>>>>>>             return features;
>>>>>>         }
>>>>>>     @@ -3766,6 +3780,7 @@ static void virtio_net_class_init(ObjectClass
>>>>>> *klass, void *data)
>>>>>>         vdc->set_features = virtio_net_set_features;
>>>>>>         vdc->bad_features = virtio_net_bad_features;
>>>>>>         vdc->reset = virtio_net_reset;
>>>>>> +    vdc->queue_reset = virtio_net_queue_reset;
>>>>>>         vdc->set_status = virtio_net_set_status;
>>>>>>         vdc->guest_notifier_mask = virtio_net_guest_notifier_mask;
>>>>>>         vdc->guest_notifier_pending = virtio_net_guest_notifier_pending;