Avi Kivity wrote: > On 11/30/2009 07:30 PM, Jan Kiszka wrote: >>>> No. But what's wrong with on_vcpu? >>>> >>> intrinsically racy. signal passing slow down things, etc. >>> >>> That said, as I've stated many times: I don't believe there's anything >>> fundamentally wrong with on_vcpu. But we might get benefits from a re-design >>> of things to avoid it whenever possible. (just like the vcpu_reset() >>> I've just posted) >>> >>> >> If you don't want immediate execution of update_guest_debug, save the >> state that shall be transferred, set some flag, and run the transfer >> before guest entry inside the vcpu threads (after putting the registers >> as older kernels may otherwise overwrite the flags register). Should >> work, may even avoid redundant calls during a gdb session. >> > > There's no guarantee the vcpu will ever exit to qemu, so you have to > signal the vcpu thread anyway. When you do that, you might as well load > the new state.
Debugging is special here as it involves vmstop before you start playing with the debug settings. But I may also oversee some corner case right now. Jan -- Siemens AG, Corporate Technology, CT T DE IT 1 Corporate Competence Center Embedded Linux
