Re: [PATCH v19 120/130] KVM: TDX: Add a method to ignore dirty logging

Isaku Yamahata
2024-03-15T01:35:13Z

On Fri, Mar 15, 2024 at 12:06:31AM +0000,
"Edgecombe, Rick P" <rick.p.edgecombe@intel.com> wrote:

> On Mon, 2024-02-26 at 00:27 -0800, isaku.yamahata@intel.com wrote:
> >
> > +static void vt_update_cpu_dirty_logging(struct kvm_vcpu *vcpu)
> > +{
> > +       if (KVM_BUG_ON(is_td_vcpu(vcpu), vcpu->kvm))
> > +               return;
> > +
> > +       vmx_update_cpu_dirty_logging(vcpu);
> > +}
>
> Discussed this first part offline, but logging it here. Since
> guest_memfd cannot have dirty logging, this is essentially bugging the
> VM if somehow they manage anyway. But it should be blocked via the code
> in check_memory_region_flags().

Will drop this patch.

> On the subject of warnings and KVM_BUG_ON(), my feeling so far is that
> this series is quite aggressive about these. Is it due the complexity
> of the series? I think maybe we can remove some of the simple ones, but
> not sure if there was already some discussion on what level is
> appropriate.

KVM_BUG_ON() was helpful at the early stage. Because we don't hit them
recently, it's okay to remove them. Will remove them.
--
Isaku Yamahata <isaku.yamahata@intel.com>