RE: [net-next 0/8][pull request] Intel Wired LAN Driver Update

["Rose, Gregory V" <gregory.v.rose@intel.com>]

> -----Original Message-----
> From: netdev-owner@vger.kernel.org [mailto:netdev-owner@vger.kernel.org]
> On Behalf Of David Miller
> Sent: Wednesday, September 21, 2011 12:14 PM
> To: Kirsher, Jeffrey T
> Cc: netdev@vger.kernel.org; gospo@redhat.com
> Subject: Re: [net-next 0/8][pull request] Intel Wired LAN Driver Update
> 
> From: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
> Date: Wed, 21 Sep 2011 03:12:46 -0700
> 
> >   - reconfigure SR-IOV init to take advantage of the new pci flag
> 
> Has this gotten any review from the PCI maintainers?

Yes, when it was posted as an RFC back in July.  It was deemed acceptable at the time.

See inline mail below.

We probably should have copied Ian Campbell on Konrad Wilk.  I have added them to the CC line in this response.

- Greg

From:	netdev-owner@vger.kernel.org on behalf of Rose, Gregory V [gregory.v.rose@intel.com]
Sent:	Friday, July 29, 2011 9:55 AM
To:	Jesse Barnes; Ian Campbell
Cc:	Konrad Rzeszutek Wilk; netdev@vger.kernel.org; davem@davemloft.net; bhutchings@solarflare.com; Kirsher, Jeffrey T; linux-pci@vger.kernel.org
Subject:	RE: [RFC net-next PATCH 1/4] pci: Add flag indicating device has been assigned by KVM

> -----Original Message-----
> From: Jesse Barnes [mailto:jbarnes@virtuousgeek.org]
> Sent: Friday, July 29, 2011 9:52 AM
> To: Ian Campbell
> Cc: Rose, Gregory V; Konrad Rzeszutek Wilk; netdev@vger.kernel.org;
> davem@davemloft.net; bhutchings@solarflare.com; Kirsher, Jeffrey T; linux-
> pci@vger.kernel.org
> Subject: Re: [RFC net-next PATCH 1/4] pci: Add flag indicating device has
> been assigned by KVM
> 
> On Thu, 28 Jul 2011 16:11:17 +0100
> Ian Campbell <ijc@hellion.org.uk> wrote:
> 
> > On Wed, 2011-07-27 at 15:17 -0700, Greg Rose wrote:
> > > Device drivers that create and destroy SR-IOV virtual functions via
> > > calls to pci_enable_sriov() and pci_disable_sriov can cause
> catastrophic
> > > failures if they attempt to destroy VFs while they are assigned to
> > > guest virtual machines.  By adding a flag for use by the KVM module
> > > to indicate that a device is assigned a device driver can check that
> > > flag and avoid destroying VFs while they are assigned and avoid system
> > > failures.
> > >
> > > Signed-off-by: Greg Rose <gregory.v.rose@intel.com>
> > > ---
> > >
> > >  include/linux/pci.h     |    2 ++
> >
> > I added Jesse and linux-pci to CC.
> >
> > >  virt/kvm/assigned-dev.c |    2 ++
> > >  virt/kvm/iommu.c        |    4 ++++
> > >  3 files changed, 8 insertions(+), 0 deletions(-)
> >
> > I suppose this would also be useful in Xen's pciback or any other system
> > which does passthrough? (Konrad CC'd for pciback)
> >
> > Is there some common lower layer we could hook this in to? (does
> > iommu_attach/detach_device make sense?) Or shall we just add the flag
> > manipulations to pciback as well?
> >
> > Ian.
> >
> > >
> > > diff --git a/include/linux/pci.h b/include/linux/pci.h
> > > index 2d29218..a297ca2 100644
> > > --- a/include/linux/pci.h
> > > +++ b/include/linux/pci.h
> > > @@ -174,6 +174,8 @@ enum pci_dev_flags {
> > >  	PCI_DEV_FLAGS_MSI_INTX_DISABLE_BUG = (__force pci_dev_flags_t) 1,
> > >  	/* Device configuration is irrevocably lost if disabled into D3 */
> > >  	PCI_DEV_FLAGS_NO_D3 = (__force pci_dev_flags_t) 2,
> > > +	/* Provide indication device is assigned by KVM */
> > > +	PCI_DEV_FLAGS_ASSIGNED = (__force pci_dev_flags_t) 4,
> > >  };
> 
> Looks fine, but I'd make the comment less redundant with the code, e.g.
> "set when the device is assigned to a guest instance" or somesuch.

Sure, sounds good to me.

Rev 2 of the RFC patches will be out in a couple of weeks, I'm away next week.

Thanks,

- Greg

> 
> --
> Jesse Barnes, Intel Open Source Technology Center
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html