[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Xen-devel] [PATCH WIP 2/5] xen/arm: set xen_platform_pci_unplug to XEN_UNPLUG_ALL

On Wed, 2012-07-04 at 12:27 +0100, Stefano Stabellini wrote:
> On Wed, 4 Jul 2012, David Vrabel wrote:
> > On 04/07/12 12:15, Stefano Stabellini wrote:
> > > Set xen_platform_pci_unplug to XEN_UNPLUG_ALL by default to make
> > > blkfront happy. The parameter doesn't make sense on ARM and should be
> > > removed.
> > 
> > Why is this parameter nonsensical on ARM?  ARM systems can have PCI devices.
> Because we shouldn't assume the presence of a PCI bus on ARM. Moreover
> it would be nice to avoid the ugly unplug protocol entirely if we can.

Also "pci" here refers to the "platform_pci" device not to PCI devices
in general.

SO I think this option is indeed nonsensical at least until such a time
as we have HVM like ARM guests (i.e. ones with a DM emulating specific
platforms) which require a PCI device which serves as the "you are
running under Xen" hook intp to the non-PV aware OSes driver subsystem.
And it's not clear that when we have such guests that a platform pci
device will be the correct solution on ARM anyway.


Xen-devel mailing list



Lists.xenproject.org is hosted with RackSpace, monitoring our
servers 24x7x365 and backed by RackSpace's Fanatical Support®.