Commit c6c4f961 authored by Li RongQing's avatar Li RongQing Committed by Paolo Bonzini
Browse files

KVM: x86/mmu: fix counting of rmap entries in pte_list_add 



Fix an off-by-one style bug in pte_list_add() where it failed to
account the last full set of SPTEs, i.e. when desc->sptes is full
and desc->more is NULL.

Merge the two "PTE_LIST_EXT-1" checks as part of the fix to avoid
an extra comparison.

Signed-off-by: default avatarLi RongQing <lirongqing@baidu.com>
Reviewed-by: default avatarSean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <1601196297-24104-1-git-send-email-lirongqing@baidu.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent ff2bb93f

arch/x86/kvm/mmu/mmu.c

+7 −5
Original line number Diff line number Diff line
@@ -856,13 +856,15 @@ static int pte_list_add(struct kvm_vcpu *vcpu, u64 *spte, 
	} else {

		rmap_printk("pte_list_add: %p %llx many->many\n", spte, *spte);

		desc = (struct pte_list_desc *)(rmap_head->val & ~1ul);

		while (desc->sptes[PTE_LIST_EXT-1] && desc->more) {

			desc = desc->more;

		while (desc->sptes[PTE_LIST_EXT-1]) {

			count += PTE_LIST_EXT;

		}

		if (desc->sptes[PTE_LIST_EXT-1]) {



			if (!desc->more) {

				desc->more = mmu_alloc_pte_list_desc(vcpu);

				desc = desc->more;

				break;

			}

			desc = desc->more;

		}

		for (i = 0; desc->sptes[i]; ++i)

			++count;