OGAWA Hirofumi <hirofumi@xxxxxxxxxxxxxxxxxx> writes: > Avi Kivity <avi@xxxxxxxxxx> writes: > >>> This seems to be complex stuff depending on hardware configurations. I'm >>> not fully understanding though, current state of it is, >>> >>> Yes, PIC is in AEOI mode if linux is using IO-APIC. Um.., kvm says >>> irq == 0 is mp_INT mode in MADT, not mp_ExtINT. >> >> That is correct, kvm doesn't connect the master 8259 output to the >> IOAPIC. Instead the 8259 is connected to LINT0 (which is configured for >> ExtInt when the IOAPIC is disabled, or for NMI which the NMI watchdog is >> enabled). >> >> However, now I can't see how it would work. auto EOI works on the INTA >> cycle, which would only occur if LINT0 is configured for ExtInt. If it >> is configured for NMI, I don't think it would issue the INTA cycle. So >> the NMI watchdog not working is actually correct for our hardware >> configuration! >> >> But I may be misunderstanding something here. > > I see. If the physical machine was configured as above, I guess (not > pretty sure, I don't have this configuration machine), IOAPIC test > (check_timer() in io_apic.c) should fail, and IOAPIC wouldn't have any > effect. And I think MADT should tell mp_ExtINT. > > Yes, I also guess the above configuration wouldn't work NMI watchdog of > IOAPIC mode, and linux will report as NMI watchdog can't work in > check_timer(). Hm.., if smp was enabled, what configuration model is used by kvm? I think this configuration model can't work on smp. Thanks. -- OGAWA Hirofumi <hirofumi@xxxxxxxxxxxxxxxxxx> -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
