On 04/05/20 20:55, Peter Xu wrote: > On Mon, May 04, 2020 at 11:55:55AM -0400, Paolo Bonzini wrote: >> The purpose of this series is to get rid of the get_dr6 accessor >> and, on Intel, of set_dr6 as well. This is done mostly in patch 2, >> since patch 3 is only the resulting cleanup. Patch 1 is a related >> bug fix that I found while inspecting the code. > > Reviewed-by: Peter Xu <peterx@xxxxxxxxxx> > > (Btw, the db_interception() change in patch 2 seems to be a real fix to me) It should be okay because vcpu->arch.dr6 is not used on AMD. However I think a kvm_update_dr6 call is missing in kvm_deliver_exception_payload, and kvm_vcpu_check_breakpoint should use kvm_queue_exception_p. I'll fix all of those. > I have that in my list, but I don't know it's "sorely" needed. :) It was low > after I knew the fact that we've got one test in kvm-unit-test, but I can for > sure do that earlier. > > I am wondering whether we still want a test in selftests if there's a similar > test in kvm-unit-test already. For this one I guess at least the guest debug > test is still missing. The guest debugging test would basically cover the gdbstub case, which is different from kvm-unit-tests. It would run similar tests to kvm-unit-tests, but #DB and #BP exceptions would be replaced by KVM_EXIT_DEBUG, and MOVs to DR would be replaced by KVM_SET_GUEST_DEBUG. It could also cover exception payload support in KVM_GET_VCPU_EVENTS, but that is more complicated because it would require support for exceptions in the selftests. Paolo
