Commit 348acf74 authored by Yu Zhang's avatar Yu Zhang
Browse files

KVM: mmu: increase the mmu_notifier_count for legacy APIs 

Intel inclusion
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I8YDCS


CVE: NA

----------------------------------------------------------------------
Fix kvm_mmu_notifier_invalidate_range_start(), which missed to increase
the mmu_notifier_count. Otherwise BUG_ON() could be triggered later, by
kvm_mmu_notifier_invalidate_range_end(), on platforms using legacy KVM
MMU notifier APIs.

Fixes: ac63cf0a ("KVM: Move MMU notifier's mmu_lock acquisition into common helper")
Reported-by: default avatarxianglai li <lixianglai@loongson.cn>
Signed-off-by: default avatarYu Zhang <yu.c.zhang@linux.intel.com>
parent c6bcd162

virt/kvm/kvm_main.c

+4 −1
Original line number Diff line number Diff line
@@ -662,6 +662,7 @@ static __always_inline int kvm_handle_hva_range_no_flush(struct mmu_notifier *mn 


	return __kvm_handle_hva_range(kvm, &range);

}

#endif /* KVM_ARCH_WANT_NEW_MMU_NOTIFIER_APIS */



static void kvm_inc_notifier_count(struct kvm *kvm, unsigned long start,

				   unsigned long end)
@@ -691,7 +692,6 @@ static void kvm_inc_notifier_count(struct kvm *kvm, unsigned long start, 
			max(kvm->mmu_notifier_range_end, end);

	}

}

#endif /* KVM_ARCH_WANT_NEW_MMU_NOTIFIER_APIS */



static void kvm_mmu_notifier_change_pte(struct mmu_notifier *mn,

					struct mm_struct *mm,
@@ -748,6 +748,9 @@ static int kvm_mmu_notifier_invalidate_range_start(struct mmu_notifier *mn, 
#else

	idx = srcu_read_lock(&kvm->srcu);

	KVM_MMU_LOCK(kvm);



	kvm_inc_notifier_count(kvm, range->start, range->end);



	need_tlb_flush = kvm_unmap_hva_range(kvm, range->start, range->end,

					     range->flags);

	/* we've to flush the tlb before the pages can be freed */