linux-next: build warning after merge of the kvm tree

From: Stephen Rothwell
Date: Mon Oct 28 2024 - 04:30:50 EST


Hi all,

After merging the kvm tree, today's linux-next build (htmldocs) produced
this warning:

Documentation/virt/kvm/locking.rst:157: ERROR: Malformed table.

+-------------------------------------------------------------------------+
| At the beginning:: |
| |
| spte.W = 0 |
| spte.Accessed = 1 |
+-------------------------------------+-----------------------------------+
| CPU 0: | CPU 1: |
+-------------------------------------+-----------------------------------+
| In mmu_spte_update():: | |
| | |
| old_spte = *spte; | |
| | |
| | |
| /* 'if' condition is satisfied. */ | |
| if (old_spte.Accessed == 1 && | |
| old_spte.W == 0) | |
| spte = new_spte; | |
+-------------------------------------+-----------------------------------+
| | on fast page fault path:: |
| | |
| | spte.W = 1 |
| | |
| | memory write on the spte:: |
| | |
| | spte.Dirty = 1 |
+-------------------------------------+-----------------------------------+
| :: | |
| | |
| else | |
| old_spte = xchg(spte, new_spte);| |
| if (old_spte.Accessed && | |
| !new_spte.Accessed) | |
| flush = true; | |
| if (old_spte.Dirty && | |
| !new_spte.Dirty) | |
| flush = true; | |
| OOPS!!! | |
+-------------------------------------+-----------------------------------+

Introduced by commit

5f6a3badbb74 ("KVM: x86/mmu: Mark page/folio accessed only when zapping leaf SPTEs")

--
Cheers,
Stephen Rothwell

Attachment: pgpm9ElxSAVYQ.pgp
Description: OpenPGP digital signature