Re: [PATCH 2/2] PCI: pci-stub module to reserve pci device

[Chris Wright]

* Greg KH (greg@xxxxxxxxx) wrote:
> On Tue, Nov 25, 2008 at 07:38:39PM -0800, Chris Wright wrote:
> > When doing device assignment with KVM there's currently nothing to
> > protect the device from having a driver in the host as well as the guest.
> > This trivial module just binds the pci device on the host to a stub
> > driver so that a real host driver can't bind to the device.  It has no
> > pci id table, it supports only dynamic ids.
> > 
> >  # echo "8086 10f5" > /sys/bus/pci/drivers/pci-stub/new_id
> >  # echo -n 0000:00:19.0 > /sys/bus/pci/drivers/e1000e/unbind
> >  # echo -n 0000:00:19.0 > /sys/bus/pci/drivers/pci-stub/bind
> >  # ls -l /sys/bus/pci/devices/0000:00:19.0/driver
> >  lrwxrwxrwx 1 root root 0 2008-11-25 19:10 /sys/bus/pci/devices/0000:00:19.0/driver -> ../../../bus/pci/drivers/pci-stub
> 
> You might want to put this somewhere in the .c or documentation files
> somewhere as well.

OK, I'll add this to the .c file for now.

> > Cc: "Kay, Allen M" <allen.m.kay@xxxxxxxxx>
> > Cc: "Nakajima, Jun" <jun.nakajima@xxxxxxxxx>
> > Signed-off-by: Chris Wright <chrisw@xxxxxxxxxxxx>
> > ---
> >  drivers/pci/Kconfig    |    9 +++++++++
> >  drivers/pci/Makefile   |    2 ++
> >  drivers/pci/pci-stub.c |   38 ++++++++++++++++++++++++++++++++++++++
> >  3 files changed, 49 insertions(+), 0 deletions(-)
> >  create mode 100644 drivers/pci/pci-stub.c
> > 
> > diff --git a/drivers/pci/Kconfig b/drivers/pci/Kconfig
> > index e1ca425..f6183df 100644
> > --- a/drivers/pci/Kconfig
> > +++ b/drivers/pci/Kconfig
> > @@ -42,6 +42,15 @@ config PCI_DEBUG
> >  
> >  	  When in doubt, say N.
> >  
> > +config PCI_STUB
> > +	tristate "PCI Stub driver"
> > +	depends on PCI
> > +	help
> > +	  Say Y or M here if you want be able to reserve a PCI device
> > +	  when it is going to be assigned to a guest.
> 
> "guest operating system"?  Otherwise, just "guest" doesn't mean much
> here in this context.

fixed

> Other than that minor thing, looks great.
> 
> Acked-by: Greg Kroah-Hartman <gregkh@xxxxxxx>

thanks,
-chris
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