KVM: x86: MMU: Consolidate BUG_ON checks for reverse-mapped sptes
authorTakuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp>
Fri, 20 Nov 2015 08:45:44 +0000 (17:45 +0900)
committerPaolo Bonzini <pbonzini@redhat.com>
Wed, 25 Nov 2015 16:26:47 +0000 (17:26 +0100)
commit77fbbbd2f09fae486190bb2bd7142647dc2a6e8b
tree540f568e2226e1cfe370c3ed7cf0bd4544b03c22
parentafd28fe1c901429eba8957f54bdb4a13cc15ae44
KVM: x86: MMU: Consolidate BUG_ON checks for reverse-mapped sptes

At some call sites of rmap_get_first() and rmap_get_next(), BUG_ON is
placed right after the call to detect unrelated sptes which must not be
found in the reverse-mapping list.

Move this check in rmap_get_first/next() so that all call sites, not
just the users of the for_each_rmap_spte() macro, will be checked the
same way.

One thing to keep in mind is that kvm_mmu_unlink_parents() also uses
rmap_get_first() to handle parent sptes.  The change will not break it
because parent sptes are present, at least until drop_parent_pte()
actually unlinks them, and not mmio-sptes.

Signed-off-by: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Documentation/virtual/kvm/mmu.txt
arch/x86/kvm/mmu.c