On 07/17/2012 11:51 AM, Alexander Graf wrote: > On 07/17/2012 06:27 PM, Scott Wood wrote: >> Determining whether we're on final expiration is based only on the >> previous value of TSR[ENW,WIS] when the timer expires. We look at TCR >> to determine whether we need to actually exit to QEMU (as opposed to a >> final expiration with no action, which still should result in the timer >> being stopped), but I don't see any problematic races there as long as >> we don't try to update TCR from that context. > > Yeah, what I was trying to say is that I would like to keep the TSR > state unmodified for the final expiry case. If user space decides to not > act upon it, it should be able to call into VCPU_RUN and have the same > behavior as if the watchdog never expired. I agree, it would be racy for QEMU to have to clear TSR if it's not doing a full reset. And that fact is making me wonder if I should have listened to you and kept TSR owned by the vcpu thread. :-) -Scott -- 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
