vhost_net_init returned -7

vhost_net_init returned -7

[Brian Jackson]

I'm trying to tinker with vhost_net. I have a 2.6.31-rc4 host kernel patched 
to support vhost_net (v5) (along with ksm if it matters). The guest is a 
debian-5.0.2 (2.6.26) install CD for now. When the guest tries to load the 
virtio-net drivers, kvm closes and prints "vhost_net_init returned -7". KVM is 
patched with your patches from 20090817.

I tried looking through the code but without adding some other debug code, 
it's not obvious where exactly it's failing. Was going to see if anyone (I 
know, not a lot of users yet) had any ideas before I dig too deep.

--Iggy

Re: vhost_net_init returned -7

[Michael S. Tsirkin]

On Fri, Aug 28, 2009 at 03:10:43PM -0500, Brian Jackson wrote:
> I'm trying to tinker with vhost_net. I have a 2.6.31-rc4 host kernel patched 
> to support vhost_net (v5) (along with ksm if it matters). The guest is a 
> debian-5.0.2 (2.6.26) install CD for now. When the guest tries to load the 
> virtio-net drivers, kvm closes and prints "vhost_net_init returned -7". KVM is 
> patched with your patches from 20090817.
> 
> I tried looking through the code but without adding some other debug code, 
> it's not obvious where exactly it's failing. Was going to see if anyone (I 
> know, not a lot of users yet) had any ideas before I dig too deep.
> 
> --Iggy

What I think you miss is eventfd support from kvm module in kernel.
Patches for this are in Avi's kvm.git tree:
git://git.kernel.org/pub/scm/linux/kernel/git/avi/kvm.git

-- 
MST

Re: vhost_net_init returned -7

[Michael S. Tsirkin]

On Fri, Aug 28, 2009 at 03:10:43PM -0500, Brian Jackson wrote:
> I'm trying to tinker with vhost_net. I have a 2.6.31-rc4 host kernel patched 
> to support vhost_net (v5) (along with ksm if it matters). The guest is a 
> debian-5.0.2 (2.6.26) install CD for now. When the guest tries to load the 
> virtio-net drivers, kvm closes and prints "vhost_net_init returned -7". KVM is 
> patched with your patches from 20090817.
> 
> I tried looking through the code but without adding some other debug code, 
> it's not obvious where exactly it's failing. Was going to see if anyone (I 
> know, not a lot of users yet) had any ideas before I dig too deep.
> 
> --Iggy

Something I forgot to mention is that userspace I posted currently rely on
guest MSI support which requires guest v2.6.31 (any rc will do). You don't need
kvm.git in guest though: kernel.org kernels should work ok.

-- 
MST

Re: vhost_net_init returned -7

[Brian Jackson]

I'm guessing that's not something the windows virtio drivers support  
yet. Do you plan on adding support for guests without msi or am I  
stuck waiting for the windows drivers to add support for msi?



On Aug 29, 2009, at 4:01 PM, "Michael S. Tsirkin" <mst@redhat.com>  
wrote:

> On Fri, Aug 28, 2009 at 03:10:43PM -0500, Brian Jackson wrote:
>> I'm trying to tinker with vhost_net. I have a 2.6.31-rc4 host  
>> kernel patched
>> to support vhost_net (v5) (along with ksm if it matters). The guest  
>> is a
>> debian-5.0.2 (2.6.26) install CD for now. When the guest tries to  
>> load the
>> virtio-net drivers, kvm closes and prints "vhost_net_init returned  
>> -7". KVM is
>> patched with your patches from 20090817.
>>
>> I tried looking through the code but without adding some other  
>> debug code,
>> it's not obvious where exactly it's failing. Was going to see if  
>> anyone (I
>> know, not a lot of users yet) had any ideas before I dig too deep.
>>
>> --Iggy
>
> Something I forgot to mention is that userspace I posted currently  
> rely on
> guest MSI support which requires guest v2.6.31 (any rc will do). You  
> don't need
> kvm.git in guest though: kernel.org kernels should work ok.
>
> -- 
> MST
> --
> 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: vhost_net_init returned -7

[Michael S. Tsirkin]

On Sat, Aug 29, 2009 at 04:38:25PM -0500, Brian Jackson wrote:
> I'm guessing that's not something the windows virtio drivers support  
> yet. Do you plan on adding support for guests without msi or am I stuck 
> waiting for the windows drivers to add support for msi?
>

I do want to support non-MSI. Host kernel KVM will have to be extended
for this, though.

>
> On Aug 29, 2009, at 4:01 PM, "Michael S. Tsirkin" <mst@redhat.com>  
> wrote:
>
>> On Fri, Aug 28, 2009 at 03:10:43PM -0500, Brian Jackson wrote:
>>> I'm trying to tinker with vhost_net. I have a 2.6.31-rc4 host kernel 
>>> patched
>>> to support vhost_net (v5) (along with ksm if it matters). The guest  
>>> is a
>>> debian-5.0.2 (2.6.26) install CD for now. When the guest tries to  
>>> load the
>>> virtio-net drivers, kvm closes and prints "vhost_net_init returned  
>>> -7". KVM is
>>> patched with your patches from 20090817.
>>>
>>> I tried looking through the code but without adding some other debug 
>>> code,
>>> it's not obvious where exactly it's failing. Was going to see if  
>>> anyone (I
>>> know, not a lot of users yet) had any ideas before I dig too deep.
>>>
>>> --Iggy
>>
>> Something I forgot to mention is that userspace I posted currently  
>> rely on
>> guest MSI support which requires guest v2.6.31 (any rc will do). You  
>> don't need
>> kvm.git in guest though: kernel.org kernels should work ok.
>>
>> -- 
>> MST
>> --
>> 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: vhost_net_init returned -7

[Avi Kivity]

On 08/30/2009 08:12 AM, Michael S. Tsirkin wrote:
> On Sat, Aug 29, 2009 at 04:38:25PM -0500, Brian Jackson wrote:
>    
>> I'm guessing that's not something the windows virtio drivers support
>> yet. Do you plan on adding support for guests without msi or am I stuck
>> waiting for the windows drivers to add support for msi?
>>
>>      
> I do want to support non-MSI. Host kernel KVM will have to be extended
> for this, though.
>
>    

You can proxy the interrupt in userspace.  I don't think we should spend 
a lot of time optimizing vhost-net pci-intx, just get it to work 
reasonably well.


-- 
I have a truly marvellous patch that fixes the bug which this
signature is too narrow to contain.

Re: vhost_net_init returned -7

[Dor Laor]

On 08/31/2009 08:33 PM, Avi Kivity wrote:
> On 08/30/2009 08:12 AM, Michael S. Tsirkin wrote:
>> On Sat, Aug 29, 2009 at 04:38:25PM -0500, Brian Jackson wrote:
>>> I'm guessing that's not something the windows virtio drivers support
>>> yet. Do you plan on adding support for guests without msi or am I stuck
>>> waiting for the windows drivers to add support for msi?

It's work in progress.

>>>
>> I do want to support non-MSI. Host kernel KVM will have to be extended
>> for this, though.
>>
>
> You can proxy the interrupt in userspace. I don't think we should spend
> a lot of time optimizing vhost-net pci-intx, just get it to work
> reasonably well.
>
>