Avi: Basically with those patches applied so far, we can do k<->k, u <->u and k->u live migration for typical case, the u->k migration has bug so far which is still debuging. But I am thinking about the corner case (pending irq) for cross migration, i.e. pending irq in valid IDT_Vectoring of kernel irqchip and those in interrupt_bitmap of user level case. In most case, there are no pending irqs, that is fine for us. In some case if there is a pending irq, cross migration need to convert between them which may be not feasible. In k->u case, we can just convert the IDT_vectoring indicated pending irq (single vector) to a interrupt_bitmap, but vice versa may not be true since user level case may have multiple pending irqs in theory though rare. In that case u->k cross migration may fail since we don't know this vectored irq comes from PIC or APIC and thus unable to push back to PIC/APIC device model. If there is only one pending irq in interrupt_bitmap, we can simply convert it to IDT_Vectoring BTW, multiple pending IRQs in interrupt_bitmap has potential architectural issue even in pure user level case due to premature IRR->ISR convert in PIC/APIC device model as we discussed.
If above limitation is fine, we can use interrupt_bitmap in SREGS data structure to carry the pending irq for kernel level too. Any opinion? thx,eddie ------------------------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now >> http://get.splunk.com/ _______________________________________________ kvm-devel mailing list kvm-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/kvm-devel