On 05/19/2011 03:30 AM, Jan Kiszka wrote:
On 2011-05-19 10:26, Gleb Natapov wrote:
On Wed, May 18, 2011 at 09:27:55PM +0200, Jan Kiszka wrote:
if an I/O is to the APIC page,
it's handled by the APIC
That's not that simple. We need to tell apart:
- if a cpu issued the request, and which one => forward to APIC
And cpu mode may affect where access is forwarded to. If cpu is in SMM
mode access to frame buffer may be forwarded to a memory (depends on
chipset configuration).
So we have a second use case for CPU-local I/O regions?
I wonder if only a single CPU can enter SMM or if all have to.
For the i440fx, it's a chipset register (not a per-CPU register).
Maybe it's per-CPU on more modern chipsets... I'm not really sure.
Regards,
Anthony Liguori
