Re: [Intel-wired-lan] [PATCH net-next 00/13] resource management using devlink reload

[Michal Swiatkowski <michal.swiatkowski@linux.intel.com>]

On Wed, Nov 16, 2022 at 08:04:56AM +0200, Leon Romanovsky wrote:
> On Tue, Nov 15, 2022 at 07:59:06PM -0600, Samudrala, Sridhar wrote:
> > On 11/15/2022 11:57 AM, Leon Romanovsky wrote:
> 
> <...>
> 
> > > > In case of ice driver lspci -vs shows:
> > > > Capabilities: [70] MSI-X: Enable+ Count=1024 Masked
> > > > 
> > > > so all vectors that hw supports (PFs, VFs, misc, etc). Because of that
> > > > total number of MSI-X in the devlink example from cover letter is 1024.
> > > > 
> > > > I see that mellanox shows:
> > > > Capabilities: [9c] MSI-X: Enable+ Count=64 Masked
> > > > 
> > > > I assume that 64 is in this case MSI-X ony for this one PF (it make
> > > > sense).
> > > Yes and PF MSI-X count can be changed through FW configuration tool, as
> > > we need to write new value when the driver is unbound and we need it to
> > > be persistent. Users are expecting to see "stable" number any time they
> > > reboot the server. It is not the case for VFs, as they are explicitly
> > > created after reboots and start "fresh" after every boot.
> > > 
> > > So we set large enough but not too large value as a default for PFs.
> > > If you find sane model of how to change it through kernel, you can count
> > > on our support.
> > 
> > I guess one main difference is that in case of ice, PF driver manager resources
> > for all its associated functions, not the FW. So the MSI-X count reported for PF
> > shows the total vectors(PF netdev, VFs, rdma, SFs). VFs talk to PF over a mailbox
> > to get their MSI-X vector information.
> 
> What is the output of lspci for ice VF when the driver is not bound?
> 
> Thanks
> 

It is the same after creating and after unbonding:
Capabilities: [70] MSI-X: Enable- Count=17 Masked-

17, because 16 for traffic and 1 for mailbox.

Thanks
> > 
> > 
> > 
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