On Lu, 2018-02-12 at 15:54 +0000, Andrew Cooper wrote: > On 12/02/18 15:08, Alexandru Isaila wrote: > > > > @@ -2619,14 +2634,31 @@ void svm_vmexit_handler(struct > > cpu_user_regs *regs) > > break; > > > > case VMEXIT_EXCEPTION_BP: > > - if ( !v->domain->debugger_attached ) > > - goto unexpected_exit_type; > > - /* AMD Vol2, 15.11: INT3, INTO, BOUND intercepts do not > > update RIP. */ > > - if ( (inst_len = __get_instruction_length(v, INSTR_INT3)) > > == 0 ) > > + inst_len = __get_instruction_length(v, INSTR_INT3); > There are multiple ways of ending up with this vmexit, and INT3 is > not > the only way. > > The old code was somewhat broken (but only in the case that a > debugger > was attached), but now with this introspection hook active, > executing > `0xcd 0x03` will end up crashing the domain because of a length > mismatch > looking for 0xcc. > > You need to inspect EXITINTINFO to work out what went on here, and > distinguish INT3 from INT $3. > > Can I suggest that you run this unit test > http://xenbits.xen.org/docs/xtf/test-swint-emulation.html under debug > introspection an check that you get all expected events? Every time > we > touch this code, we seem to break it :( > > ~Andrew > I've tested on Intel and AMD and I only get events on int3. Further more, I don't think there is any way to use the vmcb->exitintinfo because all the fields are 0 on the time of VMEXIT_EXCEPTION_BP. Did I understand the test scenario correctly?
Thanks, Alex ________________________ This email was scanned by Bitdefender _______________________________________________ Xen-devel mailing list Xenemail@example.com https://lists.xenproject.org/mailman/listinfo/xen-devel