On 2011-02-03 16:58, Avi Kivity wrote: > On 02/03/2011 05:55 PM, Jan Kiszka wrote: >>> >>> What's an interrupt window without IRET interception? >> >> I don't the details, but I thought you could get something like an >> interrupt-window-open interception by (fake-)injecting an IRQ and >> intercepting on VIRQ acceptance. That will not work if returning to and >> staying in irq-disabled guest code, therefore the timeout, but it should >> be most efficient (specifically if the guest uses NMIs for things like >> perf). >> > > Since NMIs are used to break out of irq-disabled regions (watchdog, NMI > IPIs during reboots) I'm wary of such a solution. Right, but we already use it for Intel. The timeout ensures that you can't get stuck forever. I think Xen works this way as well (minus the timeout - last time I checked). I hope AMD would finally realize what the left behind and improve it so that we can declare whatever "nice" solution just a temporary workaround. Will still take a few years, but we had the same situation on Intel. Jan -- Siemens AG, Corporate Technology, CT T DE IT 1 Corporate Competence Center Embedded Linux -- 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
