| |
|
 |
|
 |
|
|
|
| |
|
|
xen-devel
[Xen-devel] Re: [PATCH][FIX] Possible fix for spurious interrupts
On 20 Apr 2006, at 08:45, Jan Beulich wrote:
... and even worse when the interrupt belongs to a domU.
Have you heard anything from Intel on this? I am still hoping that
there is a pattern which interrupt gets triggered by
masking a certain other one, so a (perhaps more complex, but less
impacting) fix could be derived...
Arun Sharma pointed out its the same problem that FreeBSD has been
having (they also mask interrupt lines when the ISR is scheduled in an
interrupt thread). The problem is caused *by design* on many chipsets
-- the idea is that if the bootloader or OS does not know about ACPI
and cannot find the IO-APICs then interrupt lines routed to those
IO-APICs should have their interrupt fired on a legacy line (it so
happens that this usually is also the line used by the USB
controllers). They detect this by seeing if the IO-APIC RTE is masked.
Many chipsets have no way to disable this mode of operation (no need
for Linux and Windows -- when they detect and enable IO-APICs, they
never mask active RTEs). So, basically, we're screwed and have to work
around by delaying the EOI.
-- Keir
_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel
|
|
|
| |
|
Home