On Sep 12, 2016 08:17, "George Dunlap" <george.dun...@citrix.com> wrote: > > On 09/09/16 16:41, Tamas K Lengyel wrote: > > When emulating instructions the emulator maintains a small i-cache fetched > > from the guest memory. Under certain scenarios this memory region may contain > > instructions that a monitor subscriber would prefer to hide, namely INT3, and > > instead would prefer to emulate a different instruction in-place. > > > > This patch extends the vm_event interface to allow returning this i-cache via > > the vm_event response. > > So do you have a problem right now with stale caches (i.e., you modify > an INT3 back to something else in guest RAM but the emulator still > emulates the INT3)? Or is the idea here that instead of doing the > replace-singlestep-replace loop, you just tell the emulator, "Here, > emulate this instead" (without removing the INT3 from guest memory at all)? > > (Or am I completely missing the point here?) >
Hi George, it's the latter! This would make tracing with int3s a bit more flexible on multi-vcpu guests as there would be no racecondition. I use altp2m right now to get around this problem but it's always good to have a backup in case altp2m is disabled. Tamas
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