On Thu, Apr 23, 2020 at 12:09:42PM -0700, Sean Christopherson wrote:
> On Thu, Apr 16, 2020 at 06:15:07PM +0800, Xiaoyao Li wrote:
> > To make it more clear that the flag means DRn (except DR7) need to be
> > reloaded before vm entry.
> >
> > Signed-off-by: Xiaoyao Li <xiaoyao.li@xxxxxxxxx>
> > ---
> > arch/x86/include/asm/kvm_host.h | 2 +-
> > arch/x86/kvm/x86.c | 6 +++---
> > 2 files changed, 4 insertions(+), 4 deletions(-)
> >
> > diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
> > index c7da23aed79a..f465c76e6e5a 100644
> > --- a/arch/x86/include/asm/kvm_host.h
> > +++ b/arch/x86/include/asm/kvm_host.h
> > @@ -511,7 +511,7 @@ struct kvm_pmu_ops;
> > enum {
> > KVM_DEBUGREG_BP_ENABLED = 1,
> > KVM_DEBUGREG_WONT_EXIT = 2,
> > - KVM_DEBUGREG_RELOAD = 4,
> > + KVM_DEBUGREG_NEED_RELOAD = 4,
>
> My vote would be for KVM_DEBUGREG_DIRTY Any bit that is set switch_db_regs
> triggers a reload, whereas I would expect a RELOAD flag to be set _every_
> time a load is needed and thus be the only bit that's checked
But then shouldn't DIRTY be set as long as KVM_DEBUGREG_BP_ENABLED is set every
time before vmenter? Then it'll somehow go back to switch_db_regs, iiuc...
IIUC RELOAD actually wants to say "reload only for this iteration", that's why
it's cleared after each reload. So maybe... RELOAD_ONCE?
(Btw, do we have debug regs tests somewhere no matter inside guest or with
KVM_SET_GUEST_DEBUG?)
Thanks,
--
Peter Xu
