> On May 18, 2020, at 11:38 PM, Paolo Bonzini <pbonzini@xxxxxxxxxx> wrote:
>
> On 18/05/20 23:36, Felipe Franciosi wrote:
>> exception_type(ctxt->exception.vector) == EXCPT_TRAP) {
>> kvm_rip_write(vcpu, ctxt->eip);
>> - if (r && ctxt->tf)
>> + if ((r && ctxt->tf) || (vcpu->guest_debug & KVM_GUESTDBG_SINGLESTEP))
>> r = kvm_vcpu_do_singlestep(vcpu);
>
> Almost:
>
> if (r && (ctxt->tf || (vcpu->guest_debug & KVM_GUESTDBG_SINGLESTEP))
>
> This is because if r == 0 you have to exit to userspace with KVM_EXIT_MMIO
> and KVM_EXIT_IO before completing execution of the instruction. Once
> this is done, you'll get here again and you'll be able to go through
> kvm_vcpu_do_singlestep.
AHH yeah. I tested *only* with SINGLESTEP enabled and I didn't do any
MMIO/PIO, so I didn't even realise it. Thanks. Sending v2.
F.
>
> Thanks,
>
> Paolo
>
