Messages in this thread | | | Date | Mon, 12 Dec 2011 17:29:59 -0800 | Subject | Re: x2apic boot failure on recent sandy bridge system | From | Yinghai Lu <> |
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On Mon, Dec 12, 2011 at 4:25 PM, Suresh Siddha <suresh.b.siddha@intel.com> wrote: > On Mon, 2011-12-12 at 15:21 -0800, Berck E. Nash wrote: >> On 12/11/2011 08:40 PM, Yinghai Lu wrote: >> > x2apic pre-enabled skip the mapping for lapic address. so need map it >> > after fall back. >> > >> > please check attached -v5.. >> >> It appears to work correctly as far as I can tell. > > Ok. In this case, it looks like bios didn't enable interrupt-remapping > (part of vt-d) and just enabled x2apic with out touching or exporting > vt-d HW. > > Yinghai, In other scenarios where OS can't recover, mostly likely we > will fail in check_timer() when we fall back to xapic. Can we add a > printk in this case to convey the potential reason (that I mentioned in > the previous e-mail), so that the user can get more accurate information > for the check timer failure.
agree. in that case, will have problem.
but i don't think bios buy can go that far to enable intr-remapping without providing DMAR.
will check if can add print out in check_timer() when x2apic_preenabled == 1 and x2apic == 0...
Thanks
Yinghai Lu
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