On 06/21/2010 06:29 PM, Chris Lalancette wrote:
Older versions of 32-bit linux have a "Checking 'hlt' instruction" test where they repeatedly call the 'hlt' instruction, and then expect a timer interrupt to kick the CPU out of halt. This happens before any LAPIC or IOAPIC setup happens, which means that all of the APIC's are in virtual wire mode at this point. Unfortunately, the current implementation of virtual wire mode is hardcoded to only kick the BSP, so if a crash+kexec occurs on a different vcpu, it will never get kicked. This patch makes pic_unlock() do the equivalent of kvm_irq_delivery_to_apic() for the IOAPIC code. That is, it runs through all of the vcpus looking for one that is in virtual wire mode. In the normal case where LAPICs and IOAPICs are configured, this won't be used at all. In the bootstrap phase of a modern OS, before the LAPICs and IOAPICs are configured, this will have exactly the same behavior as today; VCPU0 is always looked at first, so it will always get out of the loop after the first iteration. This will only go through the loop more than once during a kexec/kdump, in which case it will only do it a few times until the kexec'ed kernel programs the LAPIC and IOAPIC.
Applied, thanks. -- 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
