From 77fbbbd2f09fae486190bb2bd7142647dc2a6e8b Mon Sep 17 00:00:00 2001 From: Takuya Yoshikawa Date: Fri, 20 Nov 2015 17:45:44 +0900 Subject: 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 Signed-off-by: Paolo Bonzini --- Documentation/virtual/kvm/mmu.txt | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'Documentation/virtual/kvm') 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 -- cgit v1.2.3