On Sat, May 09, 2020 at 03:28:44PM +0200, Paolo Bonzini wrote: > On 08/05/20 17:32, Peter Xu wrote: > > On Fri, May 08, 2020 at 12:33:57AM +0200, Paolo Bonzini wrote: > >> On 07/05/20 21:28, Peter Xu wrote: > >>>> - svm->vcpu.arch.dr6 = dr6; > >>>> + WARN_ON(svm->vcpu.arch.switch_db_regs & KVM_DEBUGREG_WONT_EXIT); > >>>> + svm->vcpu.arch.dr6 &= ~(DR_TRAP_BITS | DR6_RTM); > >>>> + svm->vcpu.arch.dr6 |= dr6 & ~DR6_FIXED_1; > >>> I failed to figure out what the above calculation is going to do... > >> > >> The calculation is merging the cause of the #DB with the guest DR6. > >> It's basically the same effect as kvm_deliver_exception_payload. > > > > Shall we introduce a helper for both kvm_deliver_exception_payload and here > > (e.g. kvm_merge_dr6)? Also, wondering whether this could be a bit easier to > > follow by defining: > > It would make sense indeed but I plan to get rid of this in 5.9 (so in > about a month), as explained in the comment. OK. I thought it would be easy to change and verify when with the selftests, however it's definitely ok to work upon it too. Thanks, -- Peter Xu
