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>

1 files changed, 2 insertions, 2 deletions

diff --git a/Documentation/virtual/kvm/mmu.txt b/Documentation/virtual/kvm/mmu.txt
index 3a4d681c3e98..daf9c0f742d2 100644
--- a/Documentation/virtual/kvm/mmu.txt
+++ b/Documentation/virtual/kvm/mmu.txt
@@ -203,10 +203,10 @@ Shadow pages contain the following information:
     page cannot be destroyed.  See role.invalid.
   parent_ptes:
     The reverse mapping for the pte/ptes pointing at this page's spt. If
-    parent_ptes bit 0 is zero, only one spte points at this pages and
+    parent_ptes bit 0 is zero, only one spte points at this page and
     parent_ptes points at this single spte, otherwise, there exists multiple
     sptes pointing at this page and (parent_ptes & ~0x1) points at a data
-    structure with a list of parent_ptes.
+    structure with a list of parent sptes.
   unsync:
     If true, then the translations in this page may not match the guest's
     translation.  This is equivalent to the state of the tlb when a pte is