[Qemu-devel] The status about vhost-net on kvm-arm?

[Qemu-devel] The status about vhost-net on kvm-arm?

[Li Liu]

Hi all,

Is anyone there can tell the current status of vhost-net on kvm-arm?

Half a year has passed from Isa Ansharullah asked this question:
http://www.spinics.net/lists/kvm-arm/msg08152.html

I have found two patches which have provided the kvm-arm support of
eventfd and irqfd:

1) [RFC PATCH 0/4] ARM: KVM: Enable the ioeventfd capability of KVM on ARM
http://lists.gnu.org/archive/html/qemu-devel/2014-01/msg01770.html

2) [RFC,v3] ARM: KVM: add irqfd and irq routing support
https://patches.linaro.org/32261/

And there's a rough patch for qemu to support eventfd from Ying-Shiuan Pan:

[Qemu-devel] [PATCH 0/4] ioeventfd support for virtio-mmio
https://lists.gnu.org/archive/html/qemu-devel/2014-02/msg00715.html

But there no any comments of this patch. And I can found nothing about qemu
to support irqfd. Do I lost the track?

If nobody try to fix it. We have a plan to complete it about virtio-mmio
supporing irqfd and multiqueue.

Re: [Qemu-devel] The status about vhost-net on kvm-arm?

[Eric Auger]

On 08/12/2014 04:41 AM, Li Liu wrote:
> Hi all,
> 
> Is anyone there can tell the current status of vhost-net on kvm-arm?
> 
> Half a year has passed from Isa Ansharullah asked this question:
> http://www.spinics.net/lists/kvm-arm/msg08152.html
> 
> I have found two patches which have provided the kvm-arm support of
> eventfd and irqfd:
> 
> 1) [RFC PATCH 0/4] ARM: KVM: Enable the ioeventfd capability of KVM on ARM
> http://lists.gnu.org/archive/html/qemu-devel/2014-01/msg01770.html
> 
> 2) [RFC,v3] ARM: KVM: add irqfd and irq routing support
> https://patches.linaro.org/32261/

Hi Li,

The patch below uses Paul Mackerras' work and removed usage of GSI
routing table. It is a simpler alternative to 2)
http://www.spinics.net/lists/kvm/msg106535.html

> 
> And there's a rough patch for qemu to support eventfd from Ying-Shiuan Pan:
> 
> [Qemu-devel] [PATCH 0/4] ioeventfd support for virtio-mmio
> https://lists.gnu.org/archive/html/qemu-devel/2014-02/msg00715.html
> 
> But there no any comments of this patch. And I can found nothing about qemu
> to support irqfd. Do I lost the track?

Actually I am using irqfd in QEMU VFIO Platform device
https://lists.nongnu.org/archive/html/qemu-devel/2014-08/msg01455.html

Best Regards

Eric

> 
> If nobody try to fix it. We have a plan to complete it about virtio-mmio
> supporing irqfd and multiqueue.
> 
> 
> 
> 
> 
> 
> --
> To unsubscribe from this list: send the line "unsubscribe kvm" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> 

Re: [Qemu-devel] The status about vhost-net on kvm-arm?

[Nikolay Nikolaev]

Hello,


On Tue, Aug 12, 2014 at 5:41 AM, Li Liu <john.liuli@huawei.com> wrote:
>
> Hi all,
>
> Is anyone there can tell the current status of vhost-net on kvm-arm?
>
> Half a year has passed from Isa Ansharullah asked this question:
> http://www.spinics.net/lists/kvm-arm/msg08152.html
>
> I have found two patches which have provided the kvm-arm support of
> eventfd and irqfd:
>
> 1) [RFC PATCH 0/4] ARM: KVM: Enable the ioeventfd capability of KVM on ARM
> http://lists.gnu.org/archive/html/qemu-devel/2014-01/msg01770.html
>
> 2) [RFC,v3] ARM: KVM: add irqfd and irq routing support
> https://patches.linaro.org/32261/
>
> And there's a rough patch for qemu to support eventfd from Ying-Shiuan Pan:
>
> [Qemu-devel] [PATCH 0/4] ioeventfd support for virtio-mmio
> https://lists.gnu.org/archive/html/qemu-devel/2014-02/msg00715.html
>
> But there no any comments of this patch. And I can found nothing about qemu
> to support irqfd. Do I lost the track?
>
> If nobody try to fix it. We have a plan to complete it about virtio-mmio
> supporing irqfd and multiqueue.
>
>

we at Virtual Open Systems did some work and tested vhost-net on ARM
back in March.
The setup was based on:
 - host kernel with our ioeventfd patches:
http://www.spinics.net/lists/kvm-arm/msg08413.html

- qemu with the aforementioned patches from Ying-Shiuan Pan
https://lists.gnu.org/archive/html/qemu-devel/2014-02/msg00715.html

The testbed was ARM Chromebook with Exynos 5250, using a 1Gbps USB3
Ethernet adapter connected to a 1Gbps switch. I can't find the actual
numbers but I remember that with multiple streams the gain was clearly
seen. Note that it used the minimum required ioventfd implementation
and not irqfd.

I guess it is feasible to think that it all can be put together and
rebased + the recent irqfd work. One can achiev even better
performance (because of the irqfd).

>
>
>
>
>
> _______________________________________________
> kvmarm mailing list
> kvmarm@lists.cs.columbia.edu
> https://lists.cs.columbia.edu/mailman/listinfo/kvmarm


regards,
Nikolay Nikolaev
Virtual Open Systems

Re: [Qemu-devel] The status about vhost-net on kvm-arm?

[Li Liu]

On 2014/8/12 15:29, Eric Auger wrote:
> On 08/12/2014 04:41 AM, Li Liu wrote:
>> Hi all,
>>
>> Is anyone there can tell the current status of vhost-net on kvm-arm?
>>
>> Half a year has passed from Isa Ansharullah asked this question:
>> http://www.spinics.net/lists/kvm-arm/msg08152.html
>>
>> I have found two patches which have provided the kvm-arm support of
>> eventfd and irqfd:
>>
>> 1) [RFC PATCH 0/4] ARM: KVM: Enable the ioeventfd capability of KVM on ARM
>> http://lists.gnu.org/archive/html/qemu-devel/2014-01/msg01770.html
>>
>> 2) [RFC,v3] ARM: KVM: add irqfd and irq routing support
>> https://patches.linaro.org/32261/
> 
> Hi Li,
> 
> The patch below uses Paul Mackerras' work and removed usage of GSI
> routing table. It is a simpler alternative to 2)
> http://www.spinics.net/lists/kvm/msg106535.html
> 

Thanks for your tips. This looks more clear.

Best Regards

Li

>>
>> And there's a rough patch for qemu to support eventfd from Ying-Shiuan Pan:
>>
>> [Qemu-devel] [PATCH 0/4] ioeventfd support for virtio-mmio
>> https://lists.gnu.org/archive/html/qemu-devel/2014-02/msg00715.html
>>
>> But there no any comments of this patch. And I can found nothing about qemu
>> to support irqfd. Do I lost the track?
> 
> Actually I am using irqfd in QEMU VFIO Platform device
> https://lists.nongnu.org/archive/html/qemu-devel/2014-08/msg01455.html
> 
> Best Regards
> 
> Eric
> 
>>
>> If nobody try to fix it. We have a plan to complete it about virtio-mmio
>> supporing irqfd and multiqueue.
>>
>>
>>
>>
>>
>>
>> --
>> To unsubscribe from this list: send the line "unsubscribe kvm" in
>> the body of a message to majordomo@vger.kernel.org
>> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>>
> 
> 
> 

Re: [Qemu-devel] The status about vhost-net on kvm-arm?

[Li Liu]

On 2014/8/12 23:47, Nikolay Nikolaev wrote:
> Hello,
> 
> 
> On Tue, Aug 12, 2014 at 5:41 AM, Li Liu <john.liuli@huawei.com> wrote:
>>
>> Hi all,
>>
>> Is anyone there can tell the current status of vhost-net on kvm-arm?
>>
>> Half a year has passed from Isa Ansharullah asked this question:
>> http://www.spinics.net/lists/kvm-arm/msg08152.html
>>
>> I have found two patches which have provided the kvm-arm support of
>> eventfd and irqfd:
>>
>> 1) [RFC PATCH 0/4] ARM: KVM: Enable the ioeventfd capability of KVM on ARM
>> http://lists.gnu.org/archive/html/qemu-devel/2014-01/msg01770.html
>>
>> 2) [RFC,v3] ARM: KVM: add irqfd and irq routing support
>> https://patches.linaro.org/32261/
>>
>> And there's a rough patch for qemu to support eventfd from Ying-Shiuan Pan:
>>
>> [Qemu-devel] [PATCH 0/4] ioeventfd support for virtio-mmio
>> https://lists.gnu.org/archive/html/qemu-devel/2014-02/msg00715.html
>>
>> But there no any comments of this patch. And I can found nothing about qemu
>> to support irqfd. Do I lost the track?
>>
>> If nobody try to fix it. We have a plan to complete it about virtio-mmio
>> supporing irqfd and multiqueue.
>>
>>
> 
> we at Virtual Open Systems did some work and tested vhost-net on ARM
> back in March.
> The setup was based on:
>  - host kernel with our ioeventfd patches:
> http://www.spinics.net/lists/kvm-arm/msg08413.html
> 
> - qemu with the aforementioned patches from Ying-Shiuan Pan
> https://lists.gnu.org/archive/html/qemu-devel/2014-02/msg00715.html
> 
> The testbed was ARM Chromebook with Exynos 5250, using a 1Gbps USB3
> Ethernet adapter connected to a 1Gbps switch. I can't find the actual
> numbers but I remember that with multiple streams the gain was clearly
> seen. Note that it used the minimum required ioventfd implementation
> and not irqfd.
> 

Yeah, we have roughly tested vhost-net without irqfd and get the same
result. And now try to see what will happen with irqfd :).

> I guess it is feasible to think that it all can be put together and
> rebased + the recent irqfd work. One can achiev even better
> performance (because of the irqfd).
> 
>>
>>
>>
>>
>>
>> _______________________________________________
>> kvmarm mailing list
>> kvmarm@lists.cs.columbia.edu
>> https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
> 
> 
> regards,
> Nikolay Nikolaev
> Virtual Open Systems
> 
> .
> 

Re: [Qemu-devel] The status about vhost-net on kvm-arm?

[Ying-Shiuan Pan]

[-- Attachment #1: Type: text/plain, Size: 2912 bytes --]

I'm so glad to see my patches also work in your environment!!
That's really exciting.
I'm also wondering what will happen if integrating with irqfd.

BTW, would share your performance number?

----
Best Regards,
潘穎軒 Yingshiuan Pan


2014-08-13 10:23 GMT+08:00 Li Liu <john.liuli@huawei.com>:

>
>
> On 2014/8/12 23:47, Nikolay Nikolaev wrote:
> > Hello,
> >
> >
> > On Tue, Aug 12, 2014 at 5:41 AM, Li Liu <john.liuli@huawei.com> wrote:
> >>
> >> Hi all,
> >>
> >> Is anyone there can tell the current status of vhost-net on kvm-arm?
> >>
> >> Half a year has passed from Isa Ansharullah asked this question:
> >> http://www.spinics.net/lists/kvm-arm/msg08152.html
> >>
> >> I have found two patches which have provided the kvm-arm support of
> >> eventfd and irqfd:
> >>
> >> 1) [RFC PATCH 0/4] ARM: KVM: Enable the ioeventfd capability of KVM on
> ARM
> >> http://lists.gnu.org/archive/html/qemu-devel/2014-01/msg01770.html
> >>
> >> 2) [RFC,v3] ARM: KVM: add irqfd and irq routing support
> >> https://patches.linaro.org/32261/
> >>
> >> And there's a rough patch for qemu to support eventfd from Ying-Shiuan
> Pan:
> >>
> >> [Qemu-devel] [PATCH 0/4] ioeventfd support for virtio-mmio
> >> https://lists.gnu.org/archive/html/qemu-devel/2014-02/msg00715.html
> >>
> >> But there no any comments of this patch. And I can found nothing about
> qemu
> >> to support irqfd. Do I lost the track?
> >>
> >> If nobody try to fix it. We have a plan to complete it about virtio-mmio
> >> supporing irqfd and multiqueue.
> >>
> >>
> >
> > we at Virtual Open Systems did some work and tested vhost-net on ARM
> > back in March.
> > The setup was based on:
> >  - host kernel with our ioeventfd patches:
> > http://www.spinics.net/lists/kvm-arm/msg08413.html
> >
> > - qemu with the aforementioned patches from Ying-Shiuan Pan
> > https://lists.gnu.org/archive/html/qemu-devel/2014-02/msg00715.html
> >
> > The testbed was ARM Chromebook with Exynos 5250, using a 1Gbps USB3
> > Ethernet adapter connected to a 1Gbps switch. I can't find the actual
> > numbers but I remember that with multiple streams the gain was clearly
> > seen. Note that it used the minimum required ioventfd implementation
> > and not irqfd.
> >
>
> Yeah, we have roughly tested vhost-net without irqfd and get the same
> result. And now try to see what will happen with irqfd :).
>
> > I guess it is feasible to think that it all can be put together and
> > rebased + the recent irqfd work. One can achiev even better
> > performance (because of the irqfd).
> >
> >>
> >>
> >>
> >>
> >>
> >> _______________________________________________
> >> kvmarm mailing list
> >> kvmarm@lists.cs.columbia.edu
> >> https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
> >
> >
> > regards,
> > Nikolay Nikolaev
> > Virtual Open Systems
> >
> > .
> >
>
>
>

[-- Attachment #2: Type: text/html, Size: 4571 bytes --]

Re: [Qemu-devel] The status about vhost-net on kvm-arm?

[Nikolay Nikolaev]

On Tue, Aug 12, 2014 at 6:47 PM, Nikolay Nikolaev
<n.nikolaev@virtualopensystems.com> wrote:
>
> Hello,
>
>
> On Tue, Aug 12, 2014 at 5:41 AM, Li Liu <john.liuli@huawei.com> wrote:
> >
> > Hi all,
> >
> > Is anyone there can tell the current status of vhost-net on kvm-arm?
> >
> > Half a year has passed from Isa Ansharullah asked this question:
> > http://www.spinics.net/lists/kvm-arm/msg08152.html
> >
> > I have found two patches which have provided the kvm-arm support of
> > eventfd and irqfd:
> >
> > 1) [RFC PATCH 0/4] ARM: KVM: Enable the ioeventfd capability of KVM on ARM
> > http://lists.gnu.org/archive/html/qemu-devel/2014-01/msg01770.html
> >
> > 2) [RFC,v3] ARM: KVM: add irqfd and irq routing support
> > https://patches.linaro.org/32261/
> >
> > And there's a rough patch for qemu to support eventfd from Ying-Shiuan Pan:
> >
> > [Qemu-devel] [PATCH 0/4] ioeventfd support for virtio-mmio
> > https://lists.gnu.org/archive/html/qemu-devel/2014-02/msg00715.html
> >
> > But there no any comments of this patch. And I can found nothing about qemu
> > to support irqfd. Do I lost the track?
> >
> > If nobody try to fix it. We have a plan to complete it about virtio-mmio
> > supporing irqfd and multiqueue.
> >
> >
>
> we at Virtual Open Systems did some work and tested vhost-net on ARM
> back in March.
> The setup was based on:
>  - host kernel with our ioeventfd patches:
> http://www.spinics.net/lists/kvm-arm/msg08413.html
>
> - qemu with the aforementioned patches from Ying-Shiuan Pan
> https://lists.gnu.org/archive/html/qemu-devel/2014-02/msg00715.html
>
> The testbed was ARM Chromebook with Exynos 5250, using a 1Gbps USB3
> Ethernet adapter connected to a 1Gbps switch. I can't find the actual
> numbers but I remember that with multiple streams the gain was clearly
> seen. Note that it used the minimum required ioventfd implementation
> and not irqfd.
>
> I guess it is feasible to think that it all can be put together and
> rebased + the recent irqfd work. One can achiev even better
> performance (because of the irqfd).
>

Managed to replicate the setup with the old versions e used in March:

Single stream from another machine to chromebook with 1Gbps USB3
Ethernet adapter.
iperf -c <address> -P 1 -i 1 -p 5001 -f k -t 10
to HOST: 858316 Kbits/sec
to GUEST: 761563 Kbits/sec

10 parallel streams
iperf -c <address> -P 10 -i 1 -p 5001 -f k -t 10
to HOST: 842420 Kbits/sec
to GUEST: 625144 Kbits/sec

>
> >
> >
> >
> >
> >
> > _______________________________________________
> > kvmarm mailing list
> > kvmarm@lists.cs.columbia.edu
> > https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
>
>
> regards,
> Nikolay Nikolaev
> Virtual Open Systems

Re: [Qemu-devel] The status about vhost-net on kvm-arm?

[Li Liu]

On 2014/8/13 17:10, Nikolay Nikolaev wrote:
> On Tue, Aug 12, 2014 at 6:47 PM, Nikolay Nikolaev
> <n.nikolaev@virtualopensystems.com> wrote:
>>
>> Hello,
>>
>>
>> On Tue, Aug 12, 2014 at 5:41 AM, Li Liu <john.liuli@huawei.com> wrote:
>>>
>>> Hi all,
>>>
>>> Is anyone there can tell the current status of vhost-net on kvm-arm?
>>>
>>> Half a year has passed from Isa Ansharullah asked this question:
>>> http://www.spinics.net/lists/kvm-arm/msg08152.html
>>>
>>> I have found two patches which have provided the kvm-arm support of
>>> eventfd and irqfd:
>>>
>>> 1) [RFC PATCH 0/4] ARM: KVM: Enable the ioeventfd capability of KVM on ARM
>>> http://lists.gnu.org/archive/html/qemu-devel/2014-01/msg01770.html
>>>
>>> 2) [RFC,v3] ARM: KVM: add irqfd and irq routing support
>>> https://patches.linaro.org/32261/
>>>
>>> And there's a rough patch for qemu to support eventfd from Ying-Shiuan Pan:
>>>
>>> [Qemu-devel] [PATCH 0/4] ioeventfd support for virtio-mmio
>>> https://lists.gnu.org/archive/html/qemu-devel/2014-02/msg00715.html
>>>
>>> But there no any comments of this patch. And I can found nothing about qemu
>>> to support irqfd. Do I lost the track?
>>>
>>> If nobody try to fix it. We have a plan to complete it about virtio-mmio
>>> supporing irqfd and multiqueue.
>>>
>>>
>>
>> we at Virtual Open Systems did some work and tested vhost-net on ARM
>> back in March.
>> The setup was based on:
>>  - host kernel with our ioeventfd patches:
>> http://www.spinics.net/lists/kvm-arm/msg08413.html
>>
>> - qemu with the aforementioned patches from Ying-Shiuan Pan
>> https://lists.gnu.org/archive/html/qemu-devel/2014-02/msg00715.html
>>
>> The testbed was ARM Chromebook with Exynos 5250, using a 1Gbps USB3
>> Ethernet adapter connected to a 1Gbps switch. I can't find the actual
>> numbers but I remember that with multiple streams the gain was clearly
>> seen. Note that it used the minimum required ioventfd implementation
>> and not irqfd.
>>
>> I guess it is feasible to think that it all can be put together and
>> rebased + the recent irqfd work. One can achiev even better
>> performance (because of the irqfd).
>>
> 
> Managed to replicate the setup with the old versions e used in March:
> 
> Single stream from another machine to chromebook with 1Gbps USB3
> Ethernet adapter.
> iperf -c <address> -P 1 -i 1 -p 5001 -f k -t 10
> to HOST: 858316 Kbits/sec
> to GUEST: 761563 Kbits/sec
> 
> 10 parallel streams
> iperf -c <address> -P 10 -i 1 -p 5001 -f k -t 10
> to HOST: 842420 Kbits/sec
> to GUEST: 625144 Kbits/sec
> 

Appreciate your work. Is it convenient for you to test the same cases
without vhost=on? Then the results will show the improvement of performance
clearly only with ioeventfd.

I will try to test it with a Hisilicon board which is ongoing.

Best regards

Li

>>
>>>
>>>
>>>
>>>
>>>
>>> _______________________________________________
>>> kvmarm mailing list
>>> kvmarm@lists.cs.columbia.edu
>>> https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
>>
>>
>> regards,
>> Nikolay Nikolaev
>> Virtual Open Systems
> 
> .
> 

Re: [Qemu-devel] The status about vhost-net on kvm-arm?

[Nikolay Nikolaev]

On Wed, Aug 13, 2014 at 12:10 PM, Nikolay Nikolaev
<n.nikolaev@virtualopensystems.com> wrote:
> On Tue, Aug 12, 2014 at 6:47 PM, Nikolay Nikolaev
> <n.nikolaev@virtualopensystems.com> wrote:
>>
>> Hello,
>>
>>
>> On Tue, Aug 12, 2014 at 5:41 AM, Li Liu <john.liuli@huawei.com> wrote:
>> >
>> > Hi all,
>> >
>> > Is anyone there can tell the current status of vhost-net on kvm-arm?
>> >
>> > Half a year has passed from Isa Ansharullah asked this question:
>> > http://www.spinics.net/lists/kvm-arm/msg08152.html
>> >
>> > I have found two patches which have provided the kvm-arm support of
>> > eventfd and irqfd:
>> >
>> > 1) [RFC PATCH 0/4] ARM: KVM: Enable the ioeventfd capability of KVM on ARM
>> > http://lists.gnu.org/archive/html/qemu-devel/2014-01/msg01770.html
>> >
>> > 2) [RFC,v3] ARM: KVM: add irqfd and irq routing support
>> > https://patches.linaro.org/32261/
>> >
>> > And there's a rough patch for qemu to support eventfd from Ying-Shiuan Pan:
>> >
>> > [Qemu-devel] [PATCH 0/4] ioeventfd support for virtio-mmio
>> > https://lists.gnu.org/archive/html/qemu-devel/2014-02/msg00715.html
>> >
>> > But there no any comments of this patch. And I can found nothing about qemu
>> > to support irqfd. Do I lost the track?
>> >
>> > If nobody try to fix it. We have a plan to complete it about virtio-mmio
>> > supporing irqfd and multiqueue.
>> >
>> >
>>
>> we at Virtual Open Systems did some work and tested vhost-net on ARM
>> back in March.
>> The setup was based on:
>>  - host kernel with our ioeventfd patches:
>> http://www.spinics.net/lists/kvm-arm/msg08413.html
>>
>> - qemu with the aforementioned patches from Ying-Shiuan Pan
>> https://lists.gnu.org/archive/html/qemu-devel/2014-02/msg00715.html
>>
>> The testbed was ARM Chromebook with Exynos 5250, using a 1Gbps USB3
>> Ethernet adapter connected to a 1Gbps switch. I can't find the actual
>> numbers but I remember that with multiple streams the gain was clearly
>> seen. Note that it used the minimum required ioventfd implementation
>> and not irqfd.
>>
>> I guess it is feasible to think that it all can be put together and
>> rebased + the recent irqfd work. One can achiev even better
>> performance (because of the irqfd).
>>
>
> Managed to replicate the setup with the old versions e used in March:
>
> Single stream from another machine to chromebook with 1Gbps USB3
> Ethernet adapter.
> iperf -c <address> -P 1 -i 1 -p 5001 -f k -t 10
> to HOST: 858316 Kbits/sec
> to GUEST: 761563 Kbits/sec
to GUEST vhost=off: 508150 Kbits/sec
>
> 10 parallel streams
> iperf -c <address> -P 10 -i 1 -p 5001 -f k -t 10
> to HOST: 842420 Kbits/sec
> to GUEST: 625144 Kbits/sec
to GUEST vhost=off: 425276 Kbits/sec
>
>>
>> >
>> >
>> >
>> >
>> >
>> > _______________________________________________
>> > kvmarm mailing list
>> > kvmarm@lists.cs.columbia.edu
>> > https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
>>
>>
>> regards,
>> Nikolay Nikolaev
>> Virtual Open Systems

Re: [Qemu-devel] The status about vhost-net on kvm-arm?

[Li Liu]

On 2014/8/13 19:25, Nikolay Nikolaev wrote:
> On Wed, Aug 13, 2014 at 12:10 PM, Nikolay Nikolaev
> <n.nikolaev@virtualopensystems.com> wrote:
>> On Tue, Aug 12, 2014 at 6:47 PM, Nikolay Nikolaev
>> <n.nikolaev@virtualopensystems.com> wrote:
>>>
>>> Hello,
>>>
>>>
>>> On Tue, Aug 12, 2014 at 5:41 AM, Li Liu <john.liuli@huawei.com> wrote:
>>>>
>>>> Hi all,
>>>>
>>>> Is anyone there can tell the current status of vhost-net on kvm-arm?
>>>>
>>>> Half a year has passed from Isa Ansharullah asked this question:
>>>> http://www.spinics.net/lists/kvm-arm/msg08152.html
>>>>
>>>> I have found two patches which have provided the kvm-arm support of
>>>> eventfd and irqfd:
>>>>
>>>> 1) [RFC PATCH 0/4] ARM: KVM: Enable the ioeventfd capability of KVM on ARM
>>>> http://lists.gnu.org/archive/html/qemu-devel/2014-01/msg01770.html
>>>>
>>>> 2) [RFC,v3] ARM: KVM: add irqfd and irq routing support
>>>> https://patches.linaro.org/32261/
>>>>
>>>> And there's a rough patch for qemu to support eventfd from Ying-Shiuan Pan:
>>>>
>>>> [Qemu-devel] [PATCH 0/4] ioeventfd support for virtio-mmio
>>>> https://lists.gnu.org/archive/html/qemu-devel/2014-02/msg00715.html
>>>>
>>>> But there no any comments of this patch. And I can found nothing about qemu
>>>> to support irqfd. Do I lost the track?
>>>>
>>>> If nobody try to fix it. We have a plan to complete it about virtio-mmio
>>>> supporing irqfd and multiqueue.
>>>>
>>>>
>>>
>>> we at Virtual Open Systems did some work and tested vhost-net on ARM
>>> back in March.
>>> The setup was based on:
>>>  - host kernel with our ioeventfd patches:
>>> http://www.spinics.net/lists/kvm-arm/msg08413.html
>>>
>>> - qemu with the aforementioned patches from Ying-Shiuan Pan
>>> https://lists.gnu.org/archive/html/qemu-devel/2014-02/msg00715.html
>>>
>>> The testbed was ARM Chromebook with Exynos 5250, using a 1Gbps USB3
>>> Ethernet adapter connected to a 1Gbps switch. I can't find the actual
>>> numbers but I remember that with multiple streams the gain was clearly
>>> seen. Note that it used the minimum required ioventfd implementation
>>> and not irqfd.
>>>
>>> I guess it is feasible to think that it all can be put together and
>>> rebased + the recent irqfd work. One can achiev even better
>>> performance (because of the irqfd).
>>>
>>
>> Managed to replicate the setup with the old versions e used in March:
>>
>> Single stream from another machine to chromebook with 1Gbps USB3
>> Ethernet adapter.
>> iperf -c <address> -P 1 -i 1 -p 5001 -f k -t 10
>> to HOST: 858316 Kbits/sec
>> to GUEST: 761563 Kbits/sec
> to GUEST vhost=off: 508150 Kbits/sec
>>
>> 10 parallel streams
>> iperf -c <address> -P 10 -i 1 -p 5001 -f k -t 10
>> to HOST: 842420 Kbits/sec
>> to GUEST: 625144 Kbits/sec
> to GUEST vhost=off: 425276 Kbits/sec

I have tested the same cases on a Hisilicon board (Cortex-A15@1G)
with Integrated 1Gbps Ethernet adapter.

iperf -c <address> -P 1 -i 1 -p 5001 -f M -t 10
to HOST: 906 Mbits/sec
to GUEST: 562 Mbits/sec
to GUEST vhost=off: 340 Mbits/sec

10 parallel streams, the performance gets <10% plus:
iperf -c <address> -P 10 -i 1 -p 5001 -f M -t 10
to HOST: 923 Mbits/sec
to GUEST: 592 Mbits/sec
to GUEST vhost=off: 364 Mbits/sec

I't easy to see vhost-net brings great performance improvements,
almost 50%+.

Li.

>>
>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> _______________________________________________
>>>> kvmarm mailing list
>>>> kvmarm@lists.cs.columbia.edu
>>>> https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
>>>
>>>
>>> regards,
>>> Nikolay Nikolaev
>>> Virtual Open Systems
> 
> .
> 

Re: [Qemu-devel] The status about vhost-net on kvm-arm?

[Joel Schopp]

>>>> we at Virtual Open Systems did some work and tested vhost-net on ARM
>>>> back in March.
>>>> The setup was based on:
>>>>   - host kernel with our ioeventfd patches:
>>>> http://www.spinics.net/lists/kvm-arm/msg08413.html
>>>>
>>>> - qemu with the aforementioned patches from Ying-Shiuan Pan
>>>> https://lists.gnu.org/archive/html/qemu-devel/2014-02/msg00715.html
>>>>
>>>> The testbed was ARM Chromebook with Exynos 5250, using a 1Gbps USB3
>>>> Ethernet adapter connected to a 1Gbps switch. I can't find the actual
>>>> numbers but I remember that with multiple streams the gain was clearly
>>>> seen. Note that it used the minimum required ioventfd implementation
>>>> and not irqfd.
>>>>
>>>> I guess it is feasible to think that it all can be put together and
>>>> rebased + the recent irqfd work. One can achiev even better
>>>> performance (because of the irqfd).
>>>>
>>> Managed to replicate the setup with the old versions e used in March:
>>>
>>> Single stream from another machine to chromebook with 1Gbps USB3
>>> Ethernet adapter.
>>> iperf -c <address> -P 1 -i 1 -p 5001 -f k -t 10
>>> to HOST: 858316 Kbits/sec
>>> to GUEST: 761563 Kbits/sec
>> to GUEST vhost=off: 508150 Kbits/sec
>>> 10 parallel streams
>>> iperf -c <address> -P 10 -i 1 -p 5001 -f k -t 10
>>> to HOST: 842420 Kbits/sec
>>> to GUEST: 625144 Kbits/sec
>> to GUEST vhost=off: 425276 Kbits/sec
> I have tested the same cases on a Hisilicon board (Cortex-A15@1G)
> with Integrated 1Gbps Ethernet adapter.
>
> iperf -c <address> -P 1 -i 1 -p 5001 -f M -t 10
> to HOST: 906 Mbits/sec
> to GUEST: 562 Mbits/sec
> to GUEST vhost=off: 340 Mbits/sec
>
> 10 parallel streams, the performance gets <10% plus:
> iperf -c <address> -P 10 -i 1 -p 5001 -f M -t 10
> to HOST: 923 Mbits/sec
> to GUEST: 592 Mbits/sec
> to GUEST vhost=off: 364 Mbits/sec
>
> I't easy to see vhost-net brings great performance improvements,
> almost 50%+.
That's pretty impressive for not even having irqfd.  I guess we should 
renew some effort to get these patches merged upstream.

Re: [Qemu-devel] The status about vhost-net on kvm-arm?

[Li Liu]

Hi Ying-Shiuan Pan,

I don't know why for missing your mail in mailbox. Sorry about that.
The results of vhost-net performance have been attached in another mail.

Do you have a plan to renew your patchset to support irqfd. If not,
we will try to finish it based on yours.

On 2014/8/14 11:50, Li Liu wrote:
> 
> 
> On 2014/8/13 19:25, Nikolay Nikolaev wrote:
>> On Wed, Aug 13, 2014 at 12:10 PM, Nikolay Nikolaev
>> <n.nikolaev@virtualopensystems.com> wrote:
>>> On Tue, Aug 12, 2014 at 6:47 PM, Nikolay Nikolaev
>>> <n.nikolaev@virtualopensystems.com> wrote:
>>>>
>>>> Hello,
>>>>
>>>>
>>>> On Tue, Aug 12, 2014 at 5:41 AM, Li Liu <john.liuli@huawei.com> wrote:
>>>>>
>>>>> Hi all,
>>>>>
>>>>> Is anyone there can tell the current status of vhost-net on kvm-arm?
>>>>>
>>>>> Half a year has passed from Isa Ansharullah asked this question:
>>>>> http://www.spinics.net/lists/kvm-arm/msg08152.html
>>>>>
>>>>> I have found two patches which have provided the kvm-arm support of
>>>>> eventfd and irqfd:
>>>>>
>>>>> 1) [RFC PATCH 0/4] ARM: KVM: Enable the ioeventfd capability of KVM on ARM
>>>>> http://lists.gnu.org/archive/html/qemu-devel/2014-01/msg01770.html
>>>>>
>>>>> 2) [RFC,v3] ARM: KVM: add irqfd and irq routing support
>>>>> https://patches.linaro.org/32261/
>>>>>
>>>>> And there's a rough patch for qemu to support eventfd from Ying-Shiuan Pan:
>>>>>
>>>>> [Qemu-devel] [PATCH 0/4] ioeventfd support for virtio-mmio
>>>>> https://lists.gnu.org/archive/html/qemu-devel/2014-02/msg00715.html
>>>>>
>>>>> But there no any comments of this patch. And I can found nothing about qemu
>>>>> to support irqfd. Do I lost the track?
>>>>>
>>>>> If nobody try to fix it. We have a plan to complete it about virtio-mmio
>>>>> supporing irqfd and multiqueue.
>>>>>
>>>>>
>>>>
>>>> we at Virtual Open Systems did some work and tested vhost-net on ARM
>>>> back in March.
>>>> The setup was based on:
>>>>  - host kernel with our ioeventfd patches:
>>>> http://www.spinics.net/lists/kvm-arm/msg08413.html
>>>>
>>>> - qemu with the aforementioned patches from Ying-Shiuan Pan
>>>> https://lists.gnu.org/archive/html/qemu-devel/2014-02/msg00715.html
>>>>
>>>> The testbed was ARM Chromebook with Exynos 5250, using a 1Gbps USB3
>>>> Ethernet adapter connected to a 1Gbps switch. I can't find the actual
>>>> numbers but I remember that with multiple streams the gain was clearly
>>>> seen. Note that it used the minimum required ioventfd implementation
>>>> and not irqfd.
>>>>
>>>> I guess it is feasible to think that it all can be put together and
>>>> rebased + the recent irqfd work. One can achiev even better
>>>> performance (because of the irqfd).
>>>>
>>>
>>> Managed to replicate the setup with the old versions e used in March:
>>>
>>> Single stream from another machine to chromebook with 1Gbps USB3
>>> Ethernet adapter.
>>> iperf -c <address> -P 1 -i 1 -p 5001 -f k -t 10
>>> to HOST: 858316 Kbits/sec
>>> to GUEST: 761563 Kbits/sec
>> to GUEST vhost=off: 508150 Kbits/sec
>>>
>>> 10 parallel streams
>>> iperf -c <address> -P 10 -i 1 -p 5001 -f k -t 10
>>> to HOST: 842420 Kbits/sec
>>> to GUEST: 625144 Kbits/sec
>> to GUEST vhost=off: 425276 Kbits/sec
> 
> I have tested the same cases on a Hisilicon board (Cortex-A15@1G)
> with Integrated 1Gbps Ethernet adapter.
> 
> iperf -c <address> -P 1 -i 1 -p 5001 -f M -t 10
> to HOST: 906 Mbits/sec
> to GUEST: 562 Mbits/sec
> to GUEST vhost=off: 340 Mbits/sec
> 
> 10 parallel streams, the performance gets <10% plus:
> iperf -c <address> -P 10 -i 1 -p 5001 -f M -t 10
> to HOST: 923 Mbits/sec
> to GUEST: 592 Mbits/sec
> to GUEST vhost=off: 364 Mbits/sec
> 
> I't easy to see vhost-net brings great performance improvements,
> almost 50%+.
> 
> Li.
> 
>>>
>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> _______________________________________________
>>>>> kvmarm mailing list
>>>>> kvmarm@lists.cs.columbia.edu
>>>>> https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
>>>>
>>>>
>>>> regards,
>>>> Nikolay Nikolaev
>>>> Virtual Open Systems
>>
>> .
>>
> 
> 
> 
> .
> 

Re: [Qemu-devel] The status about vhost-net on kvm-arm?

[Yingshiuan Pan]

[-- Attachment #1: Type: text/plain, Size: 4764 bytes --]

Hi, Li,

It's ok, I did get those mails from mailing list. I guess it was because I
did not subscribe some of mailing lists.

Currently, I think I will not have any plan to renew my patcheset since I
have resigned from my previous company, I do not have Cortex-A15 platform
to test/verify.

I'm fine with that, it would be great if you or someone can take it and
improve it.
Thanks.

----
Best Regards,
Yingshiuan Pan


2014-08-15 11:04 GMT+08:00 Li Liu <john.liuli@huawei.com>:

> Hi Ying-Shiuan Pan,
>
> I don't know why for missing your mail in mailbox. Sorry about that.
> The results of vhost-net performance have been attached in another mail.
>
> Do you have a plan to renew your patchset to support irqfd. If not,
> we will try to finish it based on yours.
>
> On 2014/8/14 11:50, Li Liu wrote:
> >
> >
> > On 2014/8/13 19:25, Nikolay Nikolaev wrote:
> >> On Wed, Aug 13, 2014 at 12:10 PM, Nikolay Nikolaev
> >> <n.nikolaev@virtualopensystems.com> wrote:
> >>> On Tue, Aug 12, 2014 at 6:47 PM, Nikolay Nikolaev
> >>> <n.nikolaev@virtualopensystems.com> wrote:
> >>>>
> >>>> Hello,
> >>>>
> >>>>
> >>>> On Tue, Aug 12, 2014 at 5:41 AM, Li Liu <john.liuli@huawei.com>
> wrote:
> >>>>>
> >>>>> Hi all,
> >>>>>
> >>>>> Is anyone there can tell the current status of vhost-net on kvm-arm?
> >>>>>
> >>>>> Half a year has passed from Isa Ansharullah asked this question:
> >>>>> http://www.spinics.net/lists/kvm-arm/msg08152.html
> >>>>>
> >>>>> I have found two patches which have provided the kvm-arm support of
> >>>>> eventfd and irqfd:
> >>>>>
> >>>>> 1) [RFC PATCH 0/4] ARM: KVM: Enable the ioeventfd capability of KVM
> on ARM
> >>>>> http://lists.gnu.org/archive/html/qemu-devel/2014-01/msg01770.html
> >>>>>
> >>>>> 2) [RFC,v3] ARM: KVM: add irqfd and irq routing support
> >>>>> https://patches.linaro.org/32261/
> >>>>>
> >>>>> And there's a rough patch for qemu to support eventfd from
> Ying-Shiuan Pan:
> >>>>>
> >>>>> [Qemu-devel] [PATCH 0/4] ioeventfd support for virtio-mmio
> >>>>> https://lists.gnu.org/archive/html/qemu-devel/2014-02/msg00715.html
> >>>>>
> >>>>> But there no any comments of this patch. And I can found nothing
> about qemu
> >>>>> to support irqfd. Do I lost the track?
> >>>>>
> >>>>> If nobody try to fix it. We have a plan to complete it about
> virtio-mmio
> >>>>> supporing irqfd and multiqueue.
> >>>>>
> >>>>>
> >>>>
> >>>> we at Virtual Open Systems did some work and tested vhost-net on ARM
> >>>> back in March.
> >>>> The setup was based on:
> >>>>  - host kernel with our ioeventfd patches:
> >>>> http://www.spinics.net/lists/kvm-arm/msg08413.html
> >>>>
> >>>> - qemu with the aforementioned patches from Ying-Shiuan Pan
> >>>> https://lists.gnu.org/archive/html/qemu-devel/2014-02/msg00715.html
> >>>>
> >>>> The testbed was ARM Chromebook with Exynos 5250, using a 1Gbps USB3
> >>>> Ethernet adapter connected to a 1Gbps switch. I can't find the actual
> >>>> numbers but I remember that with multiple streams the gain was clearly
> >>>> seen. Note that it used the minimum required ioventfd implementation
> >>>> and not irqfd.
> >>>>
> >>>> I guess it is feasible to think that it all can be put together and
> >>>> rebased + the recent irqfd work. One can achiev even better
> >>>> performance (because of the irqfd).
> >>>>
> >>>
> >>> Managed to replicate the setup with the old versions e used in March:
> >>>
> >>> Single stream from another machine to chromebook with 1Gbps USB3
> >>> Ethernet adapter.
> >>> iperf -c <address> -P 1 -i 1 -p 5001 -f k -t 10
> >>> to HOST: 858316 Kbits/sec
> >>> to GUEST: 761563 Kbits/sec
> >> to GUEST vhost=off: 508150 Kbits/sec
> >>>
> >>> 10 parallel streams
> >>> iperf -c <address> -P 10 -i 1 -p 5001 -f k -t 10
> >>> to HOST: 842420 Kbits/sec
> >>> to GUEST: 625144 Kbits/sec
> >> to GUEST vhost=off: 425276 Kbits/sec
> >
> > I have tested the same cases on a Hisilicon board (Cortex-A15@1G)
> > with Integrated 1Gbps Ethernet adapter.
> >
> > iperf -c <address> -P 1 -i 1 -p 5001 -f M -t 10
> > to HOST: 906 Mbits/sec
> > to GUEST: 562 Mbits/sec
> > to GUEST vhost=off: 340 Mbits/sec
> >
> > 10 parallel streams, the performance gets <10% plus:
> > iperf -c <address> -P 10 -i 1 -p 5001 -f M -t 10
> > to HOST: 923 Mbits/sec
> > to GUEST: 592 Mbits/sec
> > to GUEST vhost=off: 364 Mbits/sec
> >
> > I't easy to see vhost-net brings great performance improvements,
> > almost 50%+.
> >
> > Li.
> >
> >>>
> >>>>
> >>>>>
> >>>>>
> >>>>>
> >>>>>
> >>>>>
> >>>>> _______________________________________________
> >>>>> kvmarm mailing list
> >>>>> kvmarm@lists.cs.columbia.edu
> >>>>> https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
> >>>>
> >>>>
> >>>> regards,
> >>>> Nikolay Nikolaev
> >>>> Virtual Open Systems
> >>
> >> .
> >>
> >
> >
> >
> > .
> >
>
>

[-- Attachment #2: Type: text/html, Size: 7720 bytes --]

Re: [Qemu-devel] The status about vhost-net on kvm-arm?

[GAUGUEY Rémy 228890]

[-- Attachment #1: Type: text/plain, Size: 6508 bytes --]

Hello,

Using this Qemu patchset as well as recent irqfd work, I’ve tried to make vhost-net working on Cortex-A15.
Unfortunately, even if I can correctly generate irqs to the guest through irqfd, it seems to me that some pieces are still missing….
Indeed, virtio mmio interrupt status register (@ offset 0x60) is not updated by vhost thread, and reading it or writing to the peer interrupt ack register (offset 0x64) from the guest causes an VM exit …

After reading older posts, I understand that vhost-net with irqfd support could only work with MSI-X support :

On 01/20/2011 09:35 AM, Michael S. Tsirkin wrote:
“When MSI is off, each interrupt needs to be bounced through the io thread when it's set/cleared, so vhost-net causes more context switches and
higher CPU utilization than userspace virtio which handles networking in the same thread.
“
Indeed, in case of MSI-X support, Virtio spec indicates that the ISR Status field is unused…

I understand that Vhost does not emulate a complete virtio PCI adapter but only manage virtqueue operations.
However I don’t have a clear view of what is performed by Qemu and what is performed by vhost-thread…
Could someone highlight me on this point, and maybe give some clues for an implementation of Vhost with irqfd and without MSI support ???

Thanks a lot in advance.
Best regards.
Rémy



De : kvmarm-bounces@lists.cs.columbia.edu [mailto:kvmarm-bounces@lists.cs.columbia.edu] De la part de Yingshiuan Pan
Envoyé : vendredi 15 août 2014 09:25
À : Li Liu
Cc : kvmarm@lists.cs.columbia.edu; kvm@vger.kernel.org; qemu-devel
Objet : Re: [Qemu-devel] The status about vhost-net on kvm-arm?

Hi, Li,

It's ok, I did get those mails from mailing list. I guess it was because I did not subscribe some of mailing lists.

Currently, I think I will not have any plan to renew my patcheset since I have resigned from my previous company, I do not have Cortex-A15 platform to test/verify.

I'm fine with that, it would be great if you or someone can take it and improve it.
Thanks.

----
Best Regards,
Yingshiuan Pan

2014-08-15 11:04 GMT+08:00 Li Liu <john.liuli@huawei.com<mailto:john.liuli@huawei.com>>:
Hi Ying-Shiuan Pan,

I don't know why for missing your mail in mailbox. Sorry about that.
The results of vhost-net performance have been attached in another mail.

Do you have a plan to renew your patchset to support irqfd. If not,
we will try to finish it based on yours.

On 2014/8/14 11:50, Li Liu wrote:
>
>
> On 2014/8/13 19:25, Nikolay Nikolaev wrote:
>> On Wed, Aug 13, 2014 at 12:10 PM, Nikolay Nikolaev
>> <n.nikolaev@virtualopensystems.com<mailto:n.nikolaev@virtualopensystems.com>> wrote:
>>> On Tue, Aug 12, 2014 at 6:47 PM, Nikolay Nikolaev
>>> <n.nikolaev@virtualopensystems.com<mailto:n.nikolaev@virtualopensystems.com>> wrote:
>>>>
>>>> Hello,
>>>>
>>>>
>>>> On Tue, Aug 12, 2014 at 5:41 AM, Li Liu <john.liuli@huawei.com<mailto:john.liuli@huawei.com>> wrote:
>>>>>
>>>>> Hi all,
>>>>>
>>>>> Is anyone there can tell the current status of vhost-net on kvm-arm?
>>>>>
>>>>> Half a year has passed from Isa Ansharullah asked this question:
>>>>> http://www.spinics.net/lists/kvm-arm/msg08152.html
>>>>>
>>>>> I have found two patches which have provided the kvm-arm support of
>>>>> eventfd and irqfd:
>>>>>
>>>>> 1) [RFC PATCH 0/4] ARM: KVM: Enable the ioeventfd capability of KVM on ARM
>>>>> http://lists.gnu.org/archive/html/qemu-devel/2014-01/msg01770.html
>>>>>
>>>>> 2) [RFC,v3] ARM: KVM: add irqfd and irq routing support
>>>>> https://patches.linaro.org/32261/
>>>>>
>>>>> And there's a rough patch for qemu to support eventfd from Ying-Shiuan Pan:
>>>>>
>>>>> [Qemu-devel] [PATCH 0/4] ioeventfd support for virtio-mmio
>>>>> https://lists.gnu.org/archive/html/qemu-devel/2014-02/msg00715.html
>>>>>
>>>>> But there no any comments of this patch. And I can found nothing about qemu
>>>>> to support irqfd. Do I lost the track?
>>>>>
>>>>> If nobody try to fix it. We have a plan to complete it about virtio-mmio
>>>>> supporing irqfd and multiqueue.
>>>>>
>>>>>
>>>>
>>>> we at Virtual Open Systems did some work and tested vhost-net on ARM
>>>> back in March.
>>>> The setup was based on:
>>>>  - host kernel with our ioeventfd patches:
>>>> http://www.spinics.net/lists/kvm-arm/msg08413.html
>>>>
>>>> - qemu with the aforementioned patches from Ying-Shiuan Pan
>>>> https://lists.gnu.org/archive/html/qemu-devel/2014-02/msg00715.html
>>>>
>>>> The testbed was ARM Chromebook with Exynos 5250, using a 1Gbps USB3
>>>> Ethernet adapter connected to a 1Gbps switch. I can't find the actual
>>>> numbers but I remember that with multiple streams the gain was clearly
>>>> seen. Note that it used the minimum required ioventfd implementation
>>>> and not irqfd.
>>>>
>>>> I guess it is feasible to think that it all can be put together and
>>>> rebased + the recent irqfd work. One can achiev even better
>>>> performance (because of the irqfd).
>>>>
>>>
>>> Managed to replicate the setup with the old versions e used in March:
>>>
>>> Single stream from another machine to chromebook with 1Gbps USB3
>>> Ethernet adapter.
>>> iperf -c <address> -P 1 -i 1 -p 5001 -f k -t 10
>>> to HOST: 858316 Kbits/sec
>>> to GUEST: 761563 Kbits/sec
>> to GUEST vhost=off: 508150 Kbits/sec
>>>
>>> 10 parallel streams
>>> iperf -c <address> -P 10 -i 1 -p 5001 -f k -t 10
>>> to HOST: 842420 Kbits/sec
>>> to GUEST: 625144 Kbits/sec
>> to GUEST vhost=off: 425276 Kbits/sec
>
> I have tested the same cases on a Hisilicon board (Cortex-A15@1G)
> with Integrated 1Gbps Ethernet adapter.
>
> iperf -c <address> -P 1 -i 1 -p 5001 -f M -t 10
> to HOST: 906 Mbits/sec
> to GUEST: 562 Mbits/sec
> to GUEST vhost=off: 340 Mbits/sec
>
> 10 parallel streams, the performance gets <10% plus:
> iperf -c <address> -P 10 -i 1 -p 5001 -f M -t 10
> to HOST: 923 Mbits/sec
> to GUEST: 592 Mbits/sec
> to GUEST vhost=off: 364 Mbits/sec
>
> I't easy to see vhost-net brings great performance improvements,
> almost 50%+.
>
> Li.
>
>>>
>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> _______________________________________________
>>>>> kvmarm mailing list
>>>>> kvmarm@lists.cs.columbia.edu<mailto:kvmarm@lists.cs.columbia.edu>
>>>>> https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
>>>>
>>>>
>>>> regards,
>>>> Nikolay Nikolaev
>>>> Virtual Open Systems
>>
>> .
>>
>
>
>
> .
>


[-- Attachment #2: Type: text/html, Size: 16176 bytes --]

Re: [Qemu-devel] The status about vhost-net on kvm-arm?

[Li Liu]

On 2014/10/15 22:39, GAUGUEY Rémy 228890 wrote:
> Hello,
> 
> Using this Qemu patchset as well as recent irqfd work, I’ve tried to make vhost-net working on Cortex-A15.
> Unfortunately, even if I can correctly generate irqs to the guest through irqfd, it seems to me that some pieces are still missing….
> Indeed, virtio mmio interrupt status register (@ offset 0x60) is not updated by vhost thread, and reading it or writing to the peer interrupt ack register (offset 0x64) from the guest causes an VM exit …
> 

Yeah, you are correct. But it's not far away from success if have injected irqs
to the guest through irqfd. Do below things to let guest receive packets
correctly without checking VIRTIO_MMIO_INTERRUPT_STATUS in guest virtio_mmio.c:

static irqreturn_t vm_interrupt(int irq, void *opaque)
{
	......

	/* Read and acknowledge interrupts */
	/*status = readl(vm_dev->base + VIRTIO_MMIO_INTERRUPT_STATUS);
	writel(status, vm_dev->base + VIRTIO_MMIO_INTERRUPT_ACK);

	if (unlikely(status & VIRTIO_MMIO_INT_CONFIG)
			&& vdrv && vdrv->config_changed) {
		vdrv->config_changed(&vm_dev->vdev);
		ret = IRQ_HANDLED;
	}*/

	//if (likely(status & VIRTIO_MMIO_INT_VRING)) {
		spin_lock_irqsave(&vm_dev->lock, flags);
		list_for_each_entry(info, &vm_dev->virtqueues, node)
			ret |= vring_interrupt(irq, info->vq);
		spin_unlock_irqrestore(&vm_dev->lock, flags);
	//}

	return ret;
}

This is very roughly :), and a lot of coding things need to be done.

Li.

> After reading older posts, I understand that vhost-net with irqfd support could only work with MSI-X support :
> 
> On 01/20/2011 09:35 AM, Michael S. Tsirkin wrote:
> “When MSI is off, each interrupt needs to be bounced through the io thread when it's set/cleared, so vhost-net causes more context switches and
> higher CPU utilization than userspace virtio which handles networking in the same thread.
> “
> Indeed, in case of MSI-X support, Virtio spec indicates that the ISR Status field is unused…
> 
> I understand that Vhost does not emulate a complete virtio PCI adapter but only manage virtqueue operations.
> However I don’t have a clear view of what is performed by Qemu and what is performed by vhost-thread…
> Could someone highlight me on this point, and maybe give some clues for an implementation of Vhost with irqfd and without MSI support ???
> 
> Thanks a lot in advance.
> Best regards.
> Rémy
> 
> 
> 
> De : kvmarm-bounces@lists.cs.columbia.edu [mailto:kvmarm-bounces@lists.cs.columbia.edu] De la part de Yingshiuan Pan
> Envoyé : vendredi 15 août 2014 09:25
> À : Li Liu
> Cc : kvmarm@lists.cs.columbia.edu; kvm@vger.kernel.org; qemu-devel
> Objet : Re: [Qemu-devel] The status about vhost-net on kvm-arm?
> 
> Hi, Li,
> 
> It's ok, I did get those mails from mailing list. I guess it was because I did not subscribe some of mailing lists.
> 
> Currently, I think I will not have any plan to renew my patcheset since I have resigned from my previous company, I do not have Cortex-A15 platform to test/verify.
> 
> I'm fine with that, it would be great if you or someone can take it and improve it.
> Thanks.
> 
> ----
> Best Regards,
> Yingshiuan Pan
> 
> 2014-08-15 11:04 GMT+08:00 Li Liu <john.liuli@huawei.com<mailto:john.liuli@huawei.com>>:
> Hi Ying-Shiuan Pan,
> 
> I don't know why for missing your mail in mailbox. Sorry about that.
> The results of vhost-net performance have been attached in another mail.
> 
> Do you have a plan to renew your patchset to support irqfd. If not,
> we will try to finish it based on yours.
> 
> On 2014/8/14 11:50, Li Liu wrote:
>>
>>
>> On 2014/8/13 19:25, Nikolay Nikolaev wrote:
>>> On Wed, Aug 13, 2014 at 12:10 PM, Nikolay Nikolaev
>>> <n.nikolaev@virtualopensystems.com<mailto:n.nikolaev@virtualopensystems.com>> wrote:
>>>> On Tue, Aug 12, 2014 at 6:47 PM, Nikolay Nikolaev
>>>> <n.nikolaev@virtualopensystems.com<mailto:n.nikolaev@virtualopensystems.com>> wrote:
>>>>>
>>>>> Hello,
>>>>>
>>>>>
>>>>> On Tue, Aug 12, 2014 at 5:41 AM, Li Liu <john.liuli@huawei.com<mailto:john.liuli@huawei.com>> wrote:
>>>>>>
>>>>>> Hi all,
>>>>>>
>>>>>> Is anyone there can tell the current status of vhost-net on kvm-arm?
>>>>>>
>>>>>> Half a year has passed from Isa Ansharullah asked this question:
>>>>>> http://www.spinics.net/lists/kvm-arm/msg08152.html
>>>>>>
>>>>>> I have found two patches which have provided the kvm-arm support of
>>>>>> eventfd and irqfd:
>>>>>>
>>>>>> 1) [RFC PATCH 0/4] ARM: KVM: Enable the ioeventfd capability of KVM on ARM
>>>>>> http://lists.gnu.org/archive/html/qemu-devel/2014-01/msg01770.html
>>>>>>
>>>>>> 2) [RFC,v3] ARM: KVM: add irqfd and irq routing support
>>>>>> https://patches.linaro.org/32261/
>>>>>>
>>>>>> And there's a rough patch for qemu to support eventfd from Ying-Shiuan Pan:
>>>>>>
>>>>>> [Qemu-devel] [PATCH 0/4] ioeventfd support for virtio-mmio
>>>>>> https://lists.gnu.org/archive/html/qemu-devel/2014-02/msg00715.html
>>>>>>
>>>>>> But there no any comments of this patch. And I can found nothing about qemu
>>>>>> to support irqfd. Do I lost the track?
>>>>>>
>>>>>> If nobody try to fix it. We have a plan to complete it about virtio-mmio
>>>>>> supporing irqfd and multiqueue.
>>>>>>
>>>>>>
>>>>>
>>>>> we at Virtual Open Systems did some work and tested vhost-net on ARM
>>>>> back in March.
>>>>> The setup was based on:
>>>>>  - host kernel with our ioeventfd patches:
>>>>> http://www.spinics.net/lists/kvm-arm/msg08413.html
>>>>>
>>>>> - qemu with the aforementioned patches from Ying-Shiuan Pan
>>>>> https://lists.gnu.org/archive/html/qemu-devel/2014-02/msg00715.html
>>>>>
>>>>> The testbed was ARM Chromebook with Exynos 5250, using a 1Gbps USB3
>>>>> Ethernet adapter connected to a 1Gbps switch. I can't find the actual
>>>>> numbers but I remember that with multiple streams the gain was clearly
>>>>> seen. Note that it used the minimum required ioventfd implementation
>>>>> and not irqfd.
>>>>>
>>>>> I guess it is feasible to think that it all can be put together and
>>>>> rebased + the recent irqfd work. One can achiev even better
>>>>> performance (because of the irqfd).
>>>>>
>>>>
>>>> Managed to replicate the setup with the old versions e used in March:
>>>>
>>>> Single stream from another machine to chromebook with 1Gbps USB3
>>>> Ethernet adapter.
>>>> iperf -c <address> -P 1 -i 1 -p 5001 -f k -t 10
>>>> to HOST: 858316 Kbits/sec
>>>> to GUEST: 761563 Kbits/sec
>>> to GUEST vhost=off: 508150 Kbits/sec
>>>>
>>>> 10 parallel streams
>>>> iperf -c <address> -P 10 -i 1 -p 5001 -f k -t 10
>>>> to HOST: 842420 Kbits/sec
>>>> to GUEST: 625144 Kbits/sec
>>> to GUEST vhost=off: 425276 Kbits/sec
>>
>> I have tested the same cases on a Hisilicon board (Cortex-A15@1G)
>> with Integrated 1Gbps Ethernet adapter.
>>
>> iperf -c <address> -P 1 -i 1 -p 5001 -f M -t 10
>> to HOST: 906 Mbits/sec
>> to GUEST: 562 Mbits/sec
>> to GUEST vhost=off: 340 Mbits/sec
>>
>> 10 parallel streams, the performance gets <10% plus:
>> iperf -c <address> -P 10 -i 1 -p 5001 -f M -t 10
>> to HOST: 923 Mbits/sec
>> to GUEST: 592 Mbits/sec
>> to GUEST vhost=off: 364 Mbits/sec
>>
>> I't easy to see vhost-net brings great performance improvements,
>> almost 50%+.
>>
>> Li.
>>
>>>>
>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>> _______________________________________________
>>>>>> kvmarm mailing list
>>>>>> kvmarm@lists.cs.columbia.edu<mailto:kvmarm@lists.cs.columbia.edu>
>>>>>> https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
>>>>>
>>>>>
>>>>> regards,
>>>>> Nikolay Nikolaev
>>>>> Virtual Open Systems
>>>
>>> .
>>>
>>
>>
>>
>> .
>>
> 

Re: [Qemu-devel] The status about vhost-net on kvm-arm?

[GAUGUEY Rémy 228890]

Thanks for your feedback, 

>static irqreturn_t vm_interrupt(int irq, void *opaque) {
>	......
>
>	/* Read and acknowledge interrupts */
>	/*status = readl(vm_dev->base + VIRTIO_MMIO_INTERRUPT_STATUS);
>	writel(status, vm_dev->base + VIRTIO_MMIO_INTERRUPT_ACK);
>
>	if (unlikely(status & VIRTIO_MMIO_INT_CONFIG)
>			&& vdrv && vdrv->config_changed) {
>		vdrv->config_changed(&vm_dev->vdev);
>		ret = IRQ_HANDLED;
>	}*/
>
>	//if (likely(status & VIRTIO_MMIO_INT_VRING)) {
>		spin_lock_irqsave(&vm_dev->lock, flags);
>		list_for_each_entry(info, &vm_dev->virtqueues, node)
>			ret |= vring_interrupt(irq, info->vq);
>		spin_unlock_irqrestore(&vm_dev->lock, flags);
>	//}
>
>	return ret;
>}
>
>This is very roughly :), and a lot of coding things need to be done.

I agree ;-)
Anyway, with this "workaround" you disable the control plane interrupt, which is needed to bring up/down the virtio link... unless VIRTIO_NET_F_STATUS feature is off.
I was thinking about connecting those 2 registers to an ioeventfd in order to emulate them in Vhost and bypass Qemu... but AFAIK ioeventfd can only work with "write" registers.
Any idea for a long term solution ?

best regards.
Rémy

-----Message d'origine-----
De : Li Liu [mailto:john.liuli@huawei.com] 
Envoyé : vendredi 17 octobre 2014 14:27
À : GAUGUEY Rémy 228890; Yingshiuan Pan
Cc : kvmarm@lists.cs.columbia.edu; kvm@vger.kernel.org; qemu-devel
Objet : Re: [Qemu-devel] The status about vhost-net on kvm-arm?



On 2014/10/15 22:39, GAUGUEY Rémy 228890 wrote:
> Hello,
> 
> Using this Qemu patchset as well as recent irqfd work, I’ve tried to make vhost-net working on Cortex-A15.
> Unfortunately, even if I can correctly generate irqs to the guest through irqfd, it seems to me that some pieces are still missing….
> Indeed, virtio mmio interrupt status register (@ offset 0x60) is not 
> updated by vhost thread, and reading it or writing to the peer 
> interrupt ack register (offset 0x64) from the guest causes an VM exit 
> …
> 

Yeah, you are correct. But it's not far away from success if have injected irqs to the guest through irqfd. Do below things to let guest receive packets correctly without checking VIRTIO_MMIO_INTERRUPT_STATUS in guest virtio_mmio.c:

static irqreturn_t vm_interrupt(int irq, void *opaque) {
	......

	/* Read and acknowledge interrupts */
	/*status = readl(vm_dev->base + VIRTIO_MMIO_INTERRUPT_STATUS);
	writel(status, vm_dev->base + VIRTIO_MMIO_INTERRUPT_ACK);

	if (unlikely(status & VIRTIO_MMIO_INT_CONFIG)
			&& vdrv && vdrv->config_changed) {
		vdrv->config_changed(&vm_dev->vdev);
		ret = IRQ_HANDLED;
	}*/

	//if (likely(status & VIRTIO_MMIO_INT_VRING)) {
		spin_lock_irqsave(&vm_dev->lock, flags);
		list_for_each_entry(info, &vm_dev->virtqueues, node)
			ret |= vring_interrupt(irq, info->vq);
		spin_unlock_irqrestore(&vm_dev->lock, flags);
	//}

	return ret;
}

This is very roughly :), and a lot of coding things need to be done.

Li.

> After reading older posts, I understand that vhost-net with irqfd support could only work with MSI-X support :
> 
> On 01/20/2011 09:35 AM, Michael S. Tsirkin wrote:
> “When MSI is off, each interrupt needs to be bounced through the io 
> thread when it's set/cleared, so vhost-net causes more context switches and higher CPU utilization than userspace virtio which handles networking in the same thread.
> “
> Indeed, in case of MSI-X support, Virtio spec indicates that the ISR 
> Status field is unused…
> 
> I understand that Vhost does not emulate a complete virtio PCI adapter but only manage virtqueue operations.
> However I don’t have a clear view of what is performed by Qemu and 
> what is performed by vhost-thread… Could someone highlight me on this point, and maybe give some clues for an implementation of Vhost with irqfd and without MSI support ???
> 
> Thanks a lot in advance.
> Best regards.
> Rémy
> 
> 
> 
> De : kvmarm-bounces@lists.cs.columbia.edu 
> [mailto:kvmarm-bounces@lists.cs.columbia.edu] De la part de Yingshiuan 
> Pan Envoyé : vendredi 15 août 2014 09:25 À : Li Liu Cc : 
> kvmarm@lists.cs.columbia.edu; kvm@vger.kernel.org; qemu-devel Objet : 
> Re: [Qemu-devel] The status about vhost-net on kvm-arm?
> 
> Hi, Li,
> 
> It's ok, I did get those mails from mailing list. I guess it was because I did not subscribe some of mailing lists.
> 
> Currently, I think I will not have any plan to renew my patcheset since I have resigned from my previous company, I do not have Cortex-A15 platform to test/verify.
> 
> I'm fine with that, it would be great if you or someone can take it and improve it.
> Thanks.
> 
> ----
> Best Regards,
> Yingshiuan Pan
> 
> 2014-08-15 11:04 GMT+08:00 Li Liu <john.liuli@huawei.com<mailto:john.liuli@huawei.com>>:
> Hi Ying-Shiuan Pan,
> 
> I don't know why for missing your mail in mailbox. Sorry about that.
> The results of vhost-net performance have been attached in another mail.
> 
> Do you have a plan to renew your patchset to support irqfd. If not, we 
> will try to finish it based on yours.
> 
> On 2014/8/14 11:50, Li Liu wrote:
>>
>>
>> On 2014/8/13 19:25, Nikolay Nikolaev wrote:
>>> On Wed, Aug 13, 2014 at 12:10 PM, Nikolay Nikolaev 
>>> <n.nikolaev@virtualopensystems.com<mailto:n.nikolaev@virtualopensystems.com>> wrote:
>>>> On Tue, Aug 12, 2014 at 6:47 PM, Nikolay Nikolaev 
>>>> <n.nikolaev@virtualopensystems.com<mailto:n.nikolaev@virtualopensystems.com>> wrote:
>>>>>
>>>>> Hello,
>>>>>
>>>>>
>>>>> On Tue, Aug 12, 2014 at 5:41 AM, Li Liu <john.liuli@huawei.com<mailto:john.liuli@huawei.com>> wrote:
>>>>>>
>>>>>> Hi all,
>>>>>>
>>>>>> Is anyone there can tell the current status of vhost-net on kvm-arm?
>>>>>>
>>>>>> Half a year has passed from Isa Ansharullah asked this question:
>>>>>> http://www.spinics.net/lists/kvm-arm/msg08152.html
>>>>>>
>>>>>> I have found two patches which have provided the kvm-arm support 
>>>>>> of eventfd and irqfd:
>>>>>>
>>>>>> 1) [RFC PATCH 0/4] ARM: KVM: Enable the ioeventfd capability of 
>>>>>> KVM on ARM 
>>>>>> http://lists.gnu.org/archive/html/qemu-devel/2014-01/msg01770.htm
>>>>>> l
>>>>>>
>>>>>> 2) [RFC,v3] ARM: KVM: add irqfd and irq routing support 
>>>>>> https://patches.linaro.org/32261/
>>>>>>
>>>>>> And there's a rough patch for qemu to support eventfd from Ying-Shiuan Pan:
>>>>>>
>>>>>> [Qemu-devel] [PATCH 0/4] ioeventfd support for virtio-mmio 
>>>>>> https://lists.gnu.org/archive/html/qemu-devel/2014-02/msg00715.ht
>>>>>> ml
>>>>>>
>>>>>> But there no any comments of this patch. And I can found nothing 
>>>>>> about qemu to support irqfd. Do I lost the track?
>>>>>>
>>>>>> If nobody try to fix it. We have a plan to complete it about 
>>>>>> virtio-mmio supporing irqfd and multiqueue.
>>>>>>
>>>>>>
>>>>>
>>>>> we at Virtual Open Systems did some work and tested vhost-net on 
>>>>> ARM back in March.
>>>>> The setup was based on:
>>>>>  - host kernel with our ioeventfd patches:
>>>>> http://www.spinics.net/lists/kvm-arm/msg08413.html
>>>>>
>>>>> - qemu with the aforementioned patches from Ying-Shiuan Pan 
>>>>> https://lists.gnu.org/archive/html/qemu-devel/2014-02/msg00715.htm
>>>>> l
>>>>>
>>>>> The testbed was ARM Chromebook with Exynos 5250, using a 1Gbps 
>>>>> USB3 Ethernet adapter connected to a 1Gbps switch. I can't find 
>>>>> the actual numbers but I remember that with multiple streams the 
>>>>> gain was clearly seen. Note that it used the minimum required 
>>>>> ioventfd implementation and not irqfd.
>>>>>
>>>>> I guess it is feasible to think that it all can be put together 
>>>>> and rebased + the recent irqfd work. One can achiev even better 
>>>>> performance (because of the irqfd).
>>>>>
>>>>
>>>> Managed to replicate the setup with the old versions e used in March:
>>>>
>>>> Single stream from another machine to chromebook with 1Gbps USB3 
>>>> Ethernet adapter.
>>>> iperf -c <address> -P 1 -i 1 -p 5001 -f k -t 10 to HOST: 858316 
>>>> Kbits/sec to GUEST: 761563 Kbits/sec
>>> to GUEST vhost=off: 508150 Kbits/sec
>>>>
>>>> 10 parallel streams
>>>> iperf -c <address> -P 10 -i 1 -p 5001 -f k -t 10 to HOST: 842420 
>>>> Kbits/sec to GUEST: 625144 Kbits/sec
>>> to GUEST vhost=off: 425276 Kbits/sec
>>
>> I have tested the same cases on a Hisilicon board (Cortex-A15@1G) 
>> with Integrated 1Gbps Ethernet adapter.
>>
>> iperf -c <address> -P 1 -i 1 -p 5001 -f M -t 10 to HOST: 906 
>> Mbits/sec to GUEST: 562 Mbits/sec to GUEST vhost=off: 340 Mbits/sec
>>
>> 10 parallel streams, the performance gets <10% plus:
>> iperf -c <address> -P 10 -i 1 -p 5001 -f M -t 10 to HOST: 923 
>> Mbits/sec to GUEST: 592 Mbits/sec to GUEST vhost=off: 364 Mbits/sec
>>
>> I't easy to see vhost-net brings great performance improvements, 
>> almost 50%+.
>>
>> Li.
>>
>>>>
>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>> _______________________________________________
>>>>>> kvmarm mailing list
>>>>>> kvmarm@lists.cs.columbia.edu<mailto:kvmarm@lists.cs.columbia.edu>
>>>>>> https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
>>>>>
>>>>>
>>>>> regards,
>>>>> Nikolay Nikolaev
>>>>> Virtual Open Systems
>>>
>>> .
>>>
>>
>>
>>
>> .
>>
> 

Re: [Qemu-devel] The status about vhost-net on kvm-arm?

[Li Liu]

On 2014/10/17 20:49, GAUGUEY Rémy 228890 wrote:
> Thanks for your feedback, 
> 
>> static irqreturn_t vm_interrupt(int irq, void *opaque) {
>> 	......
>>
>> 	/* Read and acknowledge interrupts */
>> 	/*status = readl(vm_dev->base + VIRTIO_MMIO_INTERRUPT_STATUS);
>> 	writel(status, vm_dev->base + VIRTIO_MMIO_INTERRUPT_ACK);
>>
>> 	if (unlikely(status & VIRTIO_MMIO_INT_CONFIG)
>> 			&& vdrv && vdrv->config_changed) {
>> 		vdrv->config_changed(&vm_dev->vdev);
>> 		ret = IRQ_HANDLED;
>> 	}*/
>>
>> 	//if (likely(status & VIRTIO_MMIO_INT_VRING)) {
>> 		spin_lock_irqsave(&vm_dev->lock, flags);
>> 		list_for_each_entry(info, &vm_dev->virtqueues, node)
>> 			ret |= vring_interrupt(irq, info->vq);
>> 		spin_unlock_irqrestore(&vm_dev->lock, flags);
>> 	//}
>>
>> 	return ret;
>> }
>>
>> This is very roughly :), and a lot of coding things need to be done.
> 
> I agree ;-)
> Anyway, with this "workaround" you disable the control plane interrupt, which is needed to bring up/down the virtio link... unless VIRTIO_NET_F_STATUS feature is off.
> I was thinking about connecting those 2 registers to an ioeventfd in order to emulate them in Vhost and bypass Qemu... but AFAIK ioeventfd can only work with "write" registers.
> Any idea for a long term solution ?
> 

Yes, how to emulate mis-x is the point and I also sleep on it. Anyone have good ideas?

Li.

> best regards.
> Rémy
> 
> -----Message d'origine-----
> De : Li Liu [mailto:john.liuli@huawei.com] 
> Envoyé : vendredi 17 octobre 2014 14:27
> À : GAUGUEY Rémy 228890; Yingshiuan Pan
> Cc : kvmarm@lists.cs.columbia.edu; kvm@vger.kernel.org; qemu-devel
> Objet : Re: [Qemu-devel] The status about vhost-net on kvm-arm?
> 
> 
> 
> On 2014/10/15 22:39, GAUGUEY Rémy 228890 wrote:
>> Hello,
>>
>> Using this Qemu patchset as well as recent irqfd work, I’ve tried to make vhost-net working on Cortex-A15.
>> Unfortunately, even if I can correctly generate irqs to the guest through irqfd, it seems to me that some pieces are still missing….
>> Indeed, virtio mmio interrupt status register (@ offset 0x60) is not 
>> updated by vhost thread, and reading it or writing to the peer 
>> interrupt ack register (offset 0x64) from the guest causes an VM exit 
>> …
>>
> 
> Yeah, you are correct. But it's not far away from success if have injected irqs to the guest through irqfd. Do below things to let guest receive packets correctly without checking VIRTIO_MMIO_INTERRUPT_STATUS in guest virtio_mmio.c:
> 
> static irqreturn_t vm_interrupt(int irq, void *opaque) {
> 	......
> 
> 	/* Read and acknowledge interrupts */
> 	/*status = readl(vm_dev->base + VIRTIO_MMIO_INTERRUPT_STATUS);
> 	writel(status, vm_dev->base + VIRTIO_MMIO_INTERRUPT_ACK);
> 
> 	if (unlikely(status & VIRTIO_MMIO_INT_CONFIG)
> 			&& vdrv && vdrv->config_changed) {
> 		vdrv->config_changed(&vm_dev->vdev);
> 		ret = IRQ_HANDLED;
> 	}*/
> 
> 	//if (likely(status & VIRTIO_MMIO_INT_VRING)) {
> 		spin_lock_irqsave(&vm_dev->lock, flags);
> 		list_for_each_entry(info, &vm_dev->virtqueues, node)
> 			ret |= vring_interrupt(irq, info->vq);
> 		spin_unlock_irqrestore(&vm_dev->lock, flags);
> 	//}
> 
> 	return ret;
> }
> 
> This is very roughly :), and a lot of coding things need to be done.
> 
> Li.
> 
>> After reading older posts, I understand that vhost-net with irqfd support could only work with MSI-X support :
>>
>> On 01/20/2011 09:35 AM, Michael S. Tsirkin wrote:
>> “When MSI is off, each interrupt needs to be bounced through the io 
>> thread when it's set/cleared, so vhost-net causes more context switches and higher CPU utilization than userspace virtio which handles networking in the same thread.
>> “
>> Indeed, in case of MSI-X support, Virtio spec indicates that the ISR 
>> Status field is unused…
>>
>> I understand that Vhost does not emulate a complete virtio PCI adapter but only manage virtqueue operations.
>> However I don’t have a clear view of what is performed by Qemu and 
>> what is performed by vhost-thread… Could someone highlight me on this point, and maybe give some clues for an implementation of Vhost with irqfd and without MSI support ???
>>
>> Thanks a lot in advance.
>> Best regards.
>> Rémy
>>
>>
>>
>> De : kvmarm-bounces@lists.cs.columbia.edu 
>> [mailto:kvmarm-bounces@lists.cs.columbia.edu] De la part de Yingshiuan 
>> Pan Envoyé : vendredi 15 août 2014 09:25 À : Li Liu Cc : 
>> kvmarm@lists.cs.columbia.edu; kvm@vger.kernel.org; qemu-devel Objet : 
>> Re: [Qemu-devel] The status about vhost-net on kvm-arm?
>>
>> Hi, Li,
>>
>> It's ok, I did get those mails from mailing list. I guess it was because I did not subscribe some of mailing lists.
>>
>> Currently, I think I will not have any plan to renew my patcheset since I have resigned from my previous company, I do not have Cortex-A15 platform to test/verify.
>>
>> I'm fine with that, it would be great if you or someone can take it and improve it.
>> Thanks.
>>
>> ----
>> Best Regards,
>> Yingshiuan Pan
>>
>> 2014-08-15 11:04 GMT+08:00 Li Liu <john.liuli@huawei.com<mailto:john.liuli@huawei.com>>:
>> Hi Ying-Shiuan Pan,
>>
>> I don't know why for missing your mail in mailbox. Sorry about that.
>> The results of vhost-net performance have been attached in another mail.
>>
>> Do you have a plan to renew your patchset to support irqfd. If not, we 
>> will try to finish it based on yours.
>>
>> On 2014/8/14 11:50, Li Liu wrote:
>>>
>>>
>>> On 2014/8/13 19:25, Nikolay Nikolaev wrote:
>>>> On Wed, Aug 13, 2014 at 12:10 PM, Nikolay Nikolaev 
>>>> <n.nikolaev@virtualopensystems.com<mailto:n.nikolaev@virtualopensystems.com>> wrote:
>>>>> On Tue, Aug 12, 2014 at 6:47 PM, Nikolay Nikolaev 
>>>>> <n.nikolaev@virtualopensystems.com<mailto:n.nikolaev@virtualopensystems.com>> wrote:
>>>>>>
>>>>>> Hello,
>>>>>>
>>>>>>
>>>>>> On Tue, Aug 12, 2014 at 5:41 AM, Li Liu <john.liuli@huawei.com<mailto:john.liuli@huawei.com>> wrote:
>>>>>>>
>>>>>>> Hi all,
>>>>>>>
>>>>>>> Is anyone there can tell the current status of vhost-net on kvm-arm?
>>>>>>>
>>>>>>> Half a year has passed from Isa Ansharullah asked this question:
>>>>>>> http://www.spinics.net/lists/kvm-arm/msg08152.html
>>>>>>>
>>>>>>> I have found two patches which have provided the kvm-arm support 
>>>>>>> of eventfd and irqfd:
>>>>>>>
>>>>>>> 1) [RFC PATCH 0/4] ARM: KVM: Enable the ioeventfd capability of 
>>>>>>> KVM on ARM 
>>>>>>> http://lists.gnu.org/archive/html/qemu-devel/2014-01/msg01770.htm
>>>>>>> l
>>>>>>>
>>>>>>> 2) [RFC,v3] ARM: KVM: add irqfd and irq routing support 
>>>>>>> https://patches.linaro.org/32261/
>>>>>>>
>>>>>>> And there's a rough patch for qemu to support eventfd from Ying-Shiuan Pan:
>>>>>>>
>>>>>>> [Qemu-devel] [PATCH 0/4] ioeventfd support for virtio-mmio 
>>>>>>> https://lists.gnu.org/archive/html/qemu-devel/2014-02/msg00715.ht
>>>>>>> ml
>>>>>>>
>>>>>>> But there no any comments of this patch. And I can found nothing 
>>>>>>> about qemu to support irqfd. Do I lost the track?
>>>>>>>
>>>>>>> If nobody try to fix it. We have a plan to complete it about 
>>>>>>> virtio-mmio supporing irqfd and multiqueue.
>>>>>>>
>>>>>>>
>>>>>>
>>>>>> we at Virtual Open Systems did some work and tested vhost-net on 
>>>>>> ARM back in March.
>>>>>> The setup was based on:
>>>>>>  - host kernel with our ioeventfd patches:
>>>>>> http://www.spinics.net/lists/kvm-arm/msg08413.html
>>>>>>
>>>>>> - qemu with the aforementioned patches from Ying-Shiuan Pan 
>>>>>> https://lists.gnu.org/archive/html/qemu-devel/2014-02/msg00715.htm
>>>>>> l
>>>>>>
>>>>>> The testbed was ARM Chromebook with Exynos 5250, using a 1Gbps 
>>>>>> USB3 Ethernet adapter connected to a 1Gbps switch. I can't find 
>>>>>> the actual numbers but I remember that with multiple streams the 
>>>>>> gain was clearly seen. Note that it used the minimum required 
>>>>>> ioventfd implementation and not irqfd.
>>>>>>
>>>>>> I guess it is feasible to think that it all can be put together 
>>>>>> and rebased + the recent irqfd work. One can achiev even better 
>>>>>> performance (because of the irqfd).
>>>>>>
>>>>>
>>>>> Managed to replicate the setup with the old versions e used in March:
>>>>>
>>>>> Single stream from another machine to chromebook with 1Gbps USB3 
>>>>> Ethernet adapter.
>>>>> iperf -c <address> -P 1 -i 1 -p 5001 -f k -t 10 to HOST: 858316 
>>>>> Kbits/sec to GUEST: 761563 Kbits/sec
>>>> to GUEST vhost=off: 508150 Kbits/sec
>>>>>
>>>>> 10 parallel streams
>>>>> iperf -c <address> -P 10 -i 1 -p 5001 -f k -t 10 to HOST: 842420 
>>>>> Kbits/sec to GUEST: 625144 Kbits/sec
>>>> to GUEST vhost=off: 425276 Kbits/sec
>>>
>>> I have tested the same cases on a Hisilicon board (Cortex-A15@1G) 
>>> with Integrated 1Gbps Ethernet adapter.
>>>
>>> iperf -c <address> -P 1 -i 1 -p 5001 -f M -t 10 to HOST: 906 
>>> Mbits/sec to GUEST: 562 Mbits/sec to GUEST vhost=off: 340 Mbits/sec
>>>
>>> 10 parallel streams, the performance gets <10% plus:
>>> iperf -c <address> -P 10 -i 1 -p 5001 -f M -t 10 to HOST: 923 
>>> Mbits/sec to GUEST: 592 Mbits/sec to GUEST vhost=off: 364 Mbits/sec
>>>
>>> I't easy to see vhost-net brings great performance improvements, 
>>> almost 50%+.
>>>
>>> Li.
>>>
>>>>>
>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> _______________________________________________
>>>>>>> kvmarm mailing list
>>>>>>> kvmarm@lists.cs.columbia.edu<mailto:kvmarm@lists.cs.columbia.edu>
>>>>>>> https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
>>>>>>
>>>>>>
>>>>>> regards,
>>>>>> Nikolay Nikolaev
>>>>>> Virtual Open Systems
>>>>
>>>> .
>>>>
>>>
>>>
>>>
>>> .
>>>
>>
> 

Re: [Qemu-devel] The status about vhost-net on kvm-arm?

[Shannon Zhao]

Hi Nikolay,
>From this mail I know you guys have done some work about ioeventfd support
on kvm-arm before. Do you have plan to rework your patch based on
the new branch? If not, I think we should send a patch to make eventfd
support on kvm-arm and make vhost-net work.

Based on the new kvm-arm branch with Eric's patch "ARM: KVM: add irqfd support"
and eventfd patch in both kvm and qemu we have run virtio-mmio with vhost-net.
And with our patch to enable virtio-mmio multiple irq and irqfd support, it
work well to run vhost-net with irqfd on ARM.

The performance test data as followed :

Type of backend         bandwith(GBytes/sec) (From Host to Guest)
virtio-net              0.66
vhost-net               1.49
vhost-net with irqfd    2.01

>From this test data, vhost-net and irqfd have great improvement on performance.
So maybe it's necessary to enable ioeventfd make vhost-net work with
virtio-mmio on ARM.

It's ok if I send these patches?
Thanks,
Shannon

On 2014/8/12 23:47, Nikolay Nikolaev wrote:
> Hello,
> 
> 
> On Tue, Aug 12, 2014 at 5:41 AM, Li Liu <john.liuli@huawei.com> wrote:
>>
>> Hi all,
>>
>> Is anyone there can tell the current status of vhost-net on kvm-arm?
>>
>> Half a year has passed from Isa Ansharullah asked this question:
>> http://www.spinics.net/lists/kvm-arm/msg08152.html
>>
>> I have found two patches which have provided the kvm-arm support of
>> eventfd and irqfd:
>>
>> 1) [RFC PATCH 0/4] ARM: KVM: Enable the ioeventfd capability of KVM on ARM
>> http://lists.gnu.org/archive/html/qemu-devel/2014-01/msg01770.html
>>
>> 2) [RFC,v3] ARM: KVM: add irqfd and irq routing support
>> https://patches.linaro.org/32261/
>>
>> And there's a rough patch for qemu to support eventfd from Ying-Shiuan Pan:
>>
>> [Qemu-devel] [PATCH 0/4] ioeventfd support for virtio-mmio
>> https://lists.gnu.org/archive/html/qemu-devel/2014-02/msg00715.html
>>
>> But there no any comments of this patch. And I can found nothing about qemu
>> to support irqfd. Do I lost the track?
>>
>> If nobody try to fix it. We have a plan to complete it about virtio-mmio
>> supporing irqfd and multiqueue.
>>
>>
> 
> we at Virtual Open Systems did some work and tested vhost-net on ARM
> back in March.
> The setup was based on:
>  - host kernel with our ioeventfd patches:
> http://www.spinics.net/lists/kvm-arm/msg08413.html
> 
> - qemu with the aforementioned patches from Ying-Shiuan Pan
> https://lists.gnu.org/archive/html/qemu-devel/2014-02/msg00715.html
> 
> The testbed was ARM Chromebook with Exynos 5250, using a 1Gbps USB3
> Ethernet adapter connected to a 1Gbps switch. I can't find the actual
> numbers but I remember that with multiple streams the gain was clearly
> seen. Note that it used the minimum required ioventfd implementation
> and not irqfd.
> 
> I guess it is feasible to think that it all can be put together and
> rebased + the recent irqfd work. One can achiev even better
> performance (because of the irqfd).
> 
>>
>>
>>
>>
>>
>> _______________________________________________
>> kvmarm mailing list
>> kvmarm@lists.cs.columbia.edu
>> https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
> 
> 
> regards,
> Nikolay Nikolaev
> Virtual Open Systems
> _______________________________________________
> kvmarm mailing list
> kvmarm@lists.cs.columbia.edu
> https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
> 
> 

-- 
Shannon