From: Marcelo Tosatti <[email protected]> drop_spte should not attempt to rmap_remove a non present shadow pte.
This fixes a BUG_ON seen on kvm-autotest. Signed-off-by: Marcelo Tosatti <[email protected]> Reported-by: Lucas Meneghel Rodrigues <[email protected]> Signed-off-by: Avi Kivity <[email protected]> diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index 7ab734d..5c77e76 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -722,7 +722,7 @@ static void rmap_remove(struct kvm *kvm, u64 *spte) } } -static void set_spte_track_bits(u64 *sptep, u64 new_spte) +static int set_spte_track_bits(u64 *sptep, u64 new_spte) { pfn_t pfn; u64 old_spte = *sptep; @@ -733,19 +733,20 @@ static void set_spte_track_bits(u64 *sptep, u64 new_spte) old_spte = __xchg_spte(sptep, new_spte); if (!is_rmap_spte(old_spte)) - return; + return 0; pfn = spte_to_pfn(old_spte); if (!shadow_accessed_mask || old_spte & shadow_accessed_mask) kvm_set_pfn_accessed(pfn); if (!shadow_dirty_mask || (old_spte & shadow_dirty_mask)) kvm_set_pfn_dirty(pfn); + return 1; } static void drop_spte(struct kvm *kvm, u64 *sptep, u64 new_spte) { - set_spte_track_bits(sptep, new_spte); - rmap_remove(kvm, sptep); + if (set_spte_track_bits(sptep, new_spte)) + rmap_remove(kvm, sptep); } static u64 *rmap_next(struct kvm *kvm, unsigned long *rmapp, u64 *spte) -- To unsubscribe from this list: send the line "unsubscribe kvm-commits" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
