On Fri, Jan 30, 2015 at 12:53:19PM +1100, Alexey Kardashevskiy wrote: > At the moment sPAPR only supports 512MB window for MMIO BARs. However > modern devices might want bigger 64bit BARs. > > This extends MMIO window from 512MB to 62GB (aligned to > SPAPR_PCI_WINDOW_SPACING) and advertises it in 2 records in > the PHB "ranges" property. 32bit gets the space from > SPAPR_PCI_MEM_WIN_BUS_OFFSET till the end of 4GB, 64bit gets the rest > of the space. If no space is left, 64bit range is not advertised. > > The MMIO space size is set to old value of 0x20000000 by default > for pseries machines older than 2.3. > > The approach changes the device tree which is a guest visible change, however > it won't break migration as: > 1. we do not support migration to older QEMU versions > 2. migration to newer QEMU will migrate the device tree as well and since > the new layout only extends the old one and does not change address mappigns, > no breakage is expected here too. > > SLOF change is required to utilize this extension. > > Suggested-by: Benjamin Herrenschmidt <b...@kernel.crashing.org> > Signed-off-by: Alexey Kardashevskiy <a...@ozlabs.ru>
Reviewed-by: David Gibson <da...@gibson.dropbear.id.au>
--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson
pgp83kYPEiptV.pgp
Description: PGP signature
