Re: [RFC PATCH v5 02/45] KVM: x86/mmu: Update iter->old_spte if cmpxchg64 on mirror SPTE "fails"

[Huang, Kai]

On Wed, 2026-01-28 at 17:14 -0800, Sean Christopherson wrote:
> Pass a pointer to iter->old_spte, not simply its value, when setting an
> external SPTE in __tdp_mmu_set_spte_atomic(), so that the iterator's value
> will be updated if the cmpxchg64 to freeze the mirror SPTE fails.  The bug
> is currently benign as TDX is mutualy exclusive with all paths that do
> "local" retry", e.g. clear_dirty_gfn_range() and wrprot_gfn_range().
> 
> Fixes: 77ac7079e66d ("KVM: x86/tdp_mmu: Propagate building mirror page tables")
> Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>

Reviewed-by: Kai Huang <kai.huang@xxxxxxxxx>

Btw, do we need to cc stable?