Re: [Xen-devel] [RFC][PATCH 4/5] tools:firmware:hvmloader: reserve RMRR mappings in e820

["Chen, Tiejun" <tiejun.chen@xxxxxxxxx>]

On 2014/8/11 14:53, Jan Beulich wrote:
> > > > On 08.08.14 at 23:47, <kevin.tian@xxxxxxxxx> wrote:
> > >   From: Chen, Tiejun
> > > Sent: Thursday, August 07, 2014 4:03 AM
> > >
> > > We need to reserve all RMRR mappings in e820 to avoid any
> > > potential guest memory conflict.
> > strictly speaking besides reserving in e820, you should also poke later
> > MMIO BAR allocations to avoid confliction too. Currently it's relative
> > to low_mem_pgend, which is likely to be different from host layout
> > so it's still possible to see a virtual MMIO bar base conflicting to the
> > RMRR ranges which are supposed to be sparse.
> Correct. And what's worse: Possible collisions between RMRRs and
> the BIOS we place into the VM need to be taken care of, which may
> turn out rather tricky.
Looks BIOS itself ranges is covered with a e820 entry, so I think the 
codes to sort all entries can check this thing as well.
Thanks
Tiejun

> Jan
_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel