tree d49073cd79a4987ded9b57a1b057a6329877160f
parent c902760fb25f9c490af01e8f6bccaa8dd71cc224
author Jan Kiszka <jan.kiszka@siemens.com> 1267467029 +0100
committer Marcelo Tosatti <mtosatti@redhat.com> 1267673366 -0300

KVM: Rework of guest debug state writing

So far we synchronized any dirty VCPU state back into the kernel before
updating the guest debug state. This was a tribute to a deficite in x86
kernels before 2.6.33. But as this is an arch-dependent issue, it is
better handle in the x86 part of KVM and remove the writeback point for
generic code. This also avoids overwriting the flushed state later on if
user space decides to change some more registers before resuming the
guest.

We furthermore need to reinject guest exceptions via the appropriate
mechanism. That is KVM_SET_GUEST_DEBUG for older kernels and
KVM_SET_VCPU_EVENTS for recent ones. Using both mechanisms at the same
time will cause state corruptions.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>