Re: [Xen-devel] [PATCH 0/3] RFC: PCIe IO space multiplexing for bootable pass through HVM domain

[Isaku Yamahata <yamahata@xxxxxxxxxxxxx>]

On Thu, Apr 02, 2009 at 04:12:56PM +0900, Yuji Shimada wrote:
> On Thu, 2 Apr 2009 13:01:28 +0900
> Isaku Yamahata <yamahata@xxxxxxxxxxxxx> wrote:
> 
> > 
> > Hi all. This is for PCIe IO space multiplexing. Please comment.
> > 
> > It is not uncommon that a big iron for server consolidation has
> > many (e.g. > 16) PCIe slots. It will hold many domains, and
> > the administrator wants them to boot from pass through devices.
> > But currently up to 16 hvm domains can boot from pass through device.
> > 
> > This patch series addresses this issue by multiplexing IO space access.
> > The patches are composed of
> >     Linux part: IO space ressignment code and multiplexing driver
> >     xen part:   udev script for the driver
> >     ioemu part: make use of the PCIe io space multiplexing driver
> > 
> > 
> > Usage:
> > Add dom0 kernel command line specifying the pass through devices by
> >   guestiomuldev=[<segment>:]<bus>:<dev>[,[<segment:><bus>:dev]][,...]
> > (Don't forget add related options. pciback.hide, reassign_resources,
> > reassigndev or guestdev.)
> 
> It is nice to add "iomul" flag to "guestdev=" boot parameter, because
> segment# and bus# can be changed on rebooting. In addition to this,
> specifying pciback.hide, reassigndev and guestioemuldev is redundant.
> 
> This is a example.
> 
>         guestdev=PNP0A03:0-02.0+iomul,PNP0A03:0-1e.0+iomul

That sounds a good idea.
I haven't addressed the option integration yet because I'd like to verify
the functionality itself first.

My IO sharing code handles devices in the unit of device (not function),
so ".<func>" isn't necessary. The parser will be modified slightly.

thanks,

> Incidentally, I will submit the patch to use device path to assign
> devices to guest domain as discussed in xen-devel, after xen 3.4 is
> released.
> 
> Thanks,

-- 
yamahata

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel