On 21.03.19 23:52, Steve Rutherford wrote: > Not that I know of. > > This is surprisingly hard to implement correctly in KVM. On Intel x86 > it could be done with MTF (monitor trap fault), but you would need to > VMEXIT at each instruction boundary, and getting the behavior right > for other traps/faults is pretty hard when running around with MTF > enabled on every instruction. It could be done somewhat inaccurately > using perf counters (setup interrupt on overflow for the per-thread > instruction count, and set the base value for that counter really > high), but I'm not even sure what the current state of KVM's Perf > support is, or if this trick would work well in practice since this > isn't really what perf counters were built for. > > > > On Wed, Mar 20, 2019 at 9:33 PM liushuyu <liushuyu@xxxxxxx> wrote: >> >> Hi there, >> >> I am new to KVM API and I have a question: Is there a way to stop/kick vCPU >> after it executes a specific number of instructions? I have searched online, >> read the documentation in the Linux kernel source code, searched through the >> archives of this mailing list and I couldn't find the answer. >> >> Thanks very much for your attention. There is a very hacky way to stop/kick a VCPU on every branch using the BTS buffer and EPT, however it requires guest interaction. Most probably not what you are looking for. >> >> Thanks, >> Zixing Liu >> >> -- Thanks, David / dhildenb
