Question on skip_emulated_instructions()

[Yoshiaki Tamura <tamura.yoshiaki@lab.ntt.co.jp>]

Hi.

When handle_io() is called, rip is currently proceeded *before* actually having
I/O handled by qemu in userland.  Upon implementing Kemari for
KVM(http://www.mail-archive.com/kvm@vger.kernel.org/msg25141.html) mainly in
userland qemu, we encountered a problem that synchronizing the content of VCPU
before handling I/O in qemu is too late because rip is already proceeded in KVM,
Although we avoided this issue with temporal hack, I would like to ask a few
question on skip_emulated_instructions.

1. Does rip need to be proceeded before having I/O handled by qemu?
2. If no, is it possible to divide skip_emulated_instructions(), like
rec_emulated_instructions() to remember to next_rip, and
skip_emulated_instructions() to actually proceed the rip.
3. svm has next_rip but when it is 0, nop is emulated.  Can this be modified to
continue without emulating nop when next_rip is 0?

Thanks,

Yoshi