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

Re: [Xen-devel] GPU passthrough performance regression in >4GB vms due to XSA-60 changes

On 05/15/2014 03:23 PM, Jan Beulich wrote:
On 15.05.14 at 14:10, <tomasz.wroblewski@xxxxxxxxx> wrote:
Not really sure why it only affects 64bit vms but I've just noticed the
pci BARs for the card are being relocated by hvmloader as per some logs:

(XEN) HVM3: Relocating guest memory for lowmem MMIO space enabled
(XEN) HVM3: Relocating 0xffff pages from 0e0001000 to 14dc00000 for
lowmem MMIO hole
(XEN) HVM3: Relocating 0x1 pages from 0e0000000 to 15dbff000 for lowmem
MMIO hole

So it might be also related to that.
Indeed it might - what are the (guest) MTRR types for those regions?
It's writeback for both the 32bit and 64bit above ranges.

Xen-devel mailing list



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