Re: Statistics at the host for network nic that was PCI-Passthrough

Re: Statistics at the host for network nic that was PCI-Passthrough

[Shimon Zadok]

-------- Original Message --------
Subject: Re: [Xen-devel] Statistics at the host for network nic that 
was PCI-Passthrough
Date: 14-04-2014 12:30
 From: Shimon Zadok <shimonz@startpo.co.il>
To: Ian Campbell <Ian.Campbell@citrix.com>

Is it possible to write an extension to pciback to load a module 
specific to that h/w?
It could be a new driver for that hardware that operates by itself for 
reading these statistics from the nic...

On 14-04-2014 12:10, Ian Campbell wrote:
> On Mon, 2014-04-14 at 11:16 +0300, Shimon Zadok wrote:
>> For the case of a network nic that was PCI-Passthrough to a VM.
>>
>> Does the pciback or some API can enable the read of ethtool-like
>> statistics?
>
> These stats are h/w specific so generally only the driver within the
> guest would know how to extract them.
>
> Ian.
>
>
>
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@lists.xen.org
> http://lists.xen.org/xen-devel

-- 
Shimon Zadok
Startpo

Re: Statistics at the host for network nic that was PCI-Passthrough

[Ian Campbell]

On Mon, 2014-04-14 at 12:32 +0300, Shimon Zadok wrote:
> 
> -------- Original Message --------
> Subject: Re: [Xen-devel] Statistics at the host for network nic that 
> was PCI-Passthrough
> Date: 14-04-2014 12:30
>  From: Shimon Zadok <shimonz@startpo.co.il>
> To: Ian Campbell <Ian.Campbell@citrix.com>
> 
> Is it possible to write an extension to pciback to load a module 
> specific to that h/w?
> It could be a new driver for that hardware that operates by itself for 
> reading these statistics from the nic...

Then you would have uncoordinated accesses to the hardware from two
domains. That might work for some hardware I suppose but it certainly
isn't a good idea in general.

You'd be better off building something in the domu to export the stats
e.g. via xenstore. It could be entirely userspace I expect.

Ian.

Re: Statistics at the host for network nic that was PCI-Passthrough

[Shimon Zadok]

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The guest is not in my control. Use case is: user uploads a Guest VM he made by himself...
It could be the case that I give him an sr-iov (vf) by pci-passthrough or a pci device (not vf). I would still like to get a sense of the pci at the host level...

On April 14, 2014 12:35:01 PM GMT+02:00, Ian Campbell <Ian.Campbell@citrix.com> wrote:
>On Mon, 2014-04-14 at 12:32 +0300, Shimon Zadok wrote:
>> 
>> -------- Original Message --------
>> Subject: Re: [Xen-devel] Statistics at the host for network nic that 
>> was PCI-Passthrough
>> Date: 14-04-2014 12:30
>>  From: Shimon Zadok <shimonz@startpo.co.il>
>> To: Ian Campbell <Ian.Campbell@citrix.com>
>> 
>> Is it possible to write an extension to pciback to load a module 
>> specific to that h/w?
>> It could be a new driver for that hardware that operates by itself
>for 
>> reading these statistics from the nic...
>
>Then you would have uncoordinated accesses to the hardware from two
>domains. That might work for some hardware I suppose but it certainly
>isn't a good idea in general.
>
>You'd be better off building something in the domu to export the stats
>e.g. via xenstore. It could be entirely userspace I expect.
>
>Ian.
>
>
>
>_______________________________________________
>Xen-devel mailing list
>Xen-devel@lists.xen.org
>http://lists.xen.org/xen-devel

-- 
Sent from my Android phone with K-9 Mail. Please excuse my brevity.

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http://lists.xen.org/xen-devel

Re: Statistics at the host for network nic that was PCI-Passthrough

[Ian Campbell]

Please don't top post.

On Mon, 2014-04-14 at 14:43 +0300, Shimon Zadok wrote:
> The guest is not in my control. Use case is: user uploads a Guest VM
> he made by himself...
> It could be the case that I give him an sr-iov (vf) by pci-passthrough
> or a pci device (not vf). I would still like to get a sense of the pci
> at the host level...

I'm afraid that AFAIK this is not possible without guest (admin)
cooperation.

Ian.

Re: Statistics at the host for network nic that was PCI-Passthrough

[Andrew Cooper]

On 14/04/14 12:44, Ian Campbell wrote:
> Please don't top post.
>
> On Mon, 2014-04-14 at 14:43 +0300, Shimon Zadok wrote:
>> The guest is not in my control. Use case is: user uploads a Guest VM
>> he made by himself...
>> It could be the case that I give him an sr-iov (vf) by pci-passthrough
>> or a pci device (not vf). I would still like to get a sense of the pci
>> at the host level...
> I'm afraid that AFAIK this is not possible without guest (admin)
> cooperation.
>
> Ian.

For some SRIOV devices, there is vf accounting available from the pf,
but this is hardware and driver dependent.

For non SRIOV, all bets are off in this regard.

~Andrew

Statistics at the host for network nic that was PCI-Passthrough

[Shimon Zadok]

For the case of a network nic that was PCI-Passthrough to a VM.

Does the pciback or some API can enable the read of ethtool-like 
statistics?

-- 
Shimon Zadok
Startpo

Re: Statistics at the host for network nic that was PCI-Passthrough

[Ian Campbell]

On Mon, 2014-04-14 at 11:16 +0300, Shimon Zadok wrote:
> For the case of a network nic that was PCI-Passthrough to a VM.
> 
> Does the pciback or some API can enable the read of ethtool-like 
> statistics?

These stats are h/w specific so generally only the driver within the
guest would know how to extract them.

Ian.