On 05/03/2011 04:25 PM, OGAWA Hirofumi wrote:
Avi Kivity<avi@xxxxxxxxxx> writes: > On 05/03/2011 12:36 PM, Avi Kivity wrote: >> >>> I don't know about live migration of kvm. If we said the wiring is like >>> figure 5-2, what is required for the live migration? It was required >>> only if IMCR was required? >> >> The issue with live migration is that we can't change the running >> configuration while the system is running, like adding the IMCR or >> changing the wiring. The hardware will be programmed for the old >> configuration and will likely fail with the new one. For example, the >> current wiring has the PIT output wired to PIC IRQ0 and IOAPIC INTI0; >> we need to change it to IOAPIC INTI2 instead. >> > > btw, I believe that the configuration currently implemented is legal > (it's similar to config 7 in table 5-2 of the mpspec); the only problem > is that it can't support the NMI watchdog through the I/O APIC trick, > yet we allow it through a hack. I'm confused a bit. "config 7 in table 5-2" says PIT output wired to IOAPIC INTIN2. So, we don't need to change it?
We're like config 7 in that the 8259A output isn't wired to the IOAPIC. However we're unlike config 7 in that the PIT output is wired to IOAPIC INTIN0. I think we can keep it that way.
> Something we can do is connect the 8259A output to the I/O APIC INTIN2; > it should be masked so live migration will continue to work. We just > have to make sure that the guest is able to find that it is connected there. 8259A INTR to IOAPIC INTIN2 sounds strange. Isn't it IOAPIC INTIN0?
Usually yes, but we already have the PIT wired to INTIN0. I saw that the kernel consults the mptable to see which pin to use, so with the right BIOS magic we can get things to work.
-- error compiling committee.c: too many arguments to function -- 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
