On Sun, Jul 11, 2010 at 09:30:59PM +0300, Avi Kivity wrote: > On 07/11/2010 09:26 PM, Alex Williamson wrote: > >On Sun, 2010-07-11 at 21:14 +0300, Avi Kivity wrote: > >>On 07/11/2010 09:09 PM, Alex Williamson wrote: > >>>For device assignment, we need to know when the VM writes an end > >>>of interrupt to the APIC, which allows us to de-assert the interrupt > >>>line and clear the DisINTx bit. Add a new wrapper for ioapic > >>>generated interrupts with a callback on eoi and create an interface > >>>for drivers to be notified on eoi. > >>> > >>You aren't going to get this with kvm's in-kernel irqchip, so we need a > >>new interface there. > >Registering an eventfd for the eoi seems like a reasonable alternative. > > I'm worried about that racing (with what?) With device asserting the interrupt? Need to make sure that all possible scenarious work well: device asserts interrupt driver clears interrupt device asserts interrupt eoi device asserts interrupt driver clears interrupt eoi device asserts interrupt etc Not that I see issues, these are things we need to check. > >I also need to figure out how to avoid bouncing the vfio interrupt > >events through qemu, but it's a functional start. Thanks, > > I thought the scheduler has/wants to have something that moves the > irq to whatever thread it wakes up. With irqfd, it would flow > naturally. > > -- > I have a truly marvellous patch that fixes the bug which this > signature is too narrow to contain. -- 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
