Re: [RFC PATCH v5 20/45] KVM: x86/mmu: Allocate/free S-EPT pages using tdx_{alloc,free}_control_page()

[Huang, Kai]

On Tue, 2026-02-03 at 12:17 -0800, Sean Christopherson wrote:
> On Tue, Feb 03, 2026, Kai Huang wrote:
> > On Wed, 2026-01-28 at 17:14 -0800, Sean Christopherson wrote:
> > >   	int (*set_external_spte)(struct kvm *kvm, gfn_t gfn, enum pg_level level,
> > >   				 u64 mirror_spte);
> > > -
> > > -	/* Update external page tables for page table about to be freed. */
> > >   	void (*reclaim_external_sp)(struct kvm *kvm, gfn_t gfn,
> > >   				    struct kvm_mmu_page *sp);
> > > -
> > > -	/* Update external page table from spte getting removed, and flush TLB. */
> > 
> > The above two comments are still useful to me.
> > 
> > Not sure why do you want to remove them, especially in _this_ patch?
> 
> My intent was to replace the individual comments with a more generic comment for
> all of the "external" hooks.  For things like "and flush TLB", IMO those comments
> belong at the call sites, not at this point.  E.g. _KVM_ doesn't require a TLB
> flush in all cases.  And so for the definition of the hooks, I would prefer a more
> generic comment, so that if there are details that matter to the usage, they are
> documented there.

I see.  You actually mentioned "propagate changes in mirror page tables to
the external pages" in the new comment, so all make sense to me now.