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: Li RongQing <lirongqing@baidu.com>
Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <1601196297-24104-1-git-send-email-lirongqing@baidu.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Li RongQing 2020-09-27 16:44:57 +08:00 committed by Paolo Bonzini
parent ff2bb93f53
commit c6c4f961cb
1 changed files with 7 additions and 5 deletions

View File

@ -856,13 +856,15 @@ static int pte_list_add(struct kvm_vcpu *vcpu, u64 *spte,
} else { } else {
rmap_printk("pte_list_add: %p %llx many->many\n", spte, *spte); rmap_printk("pte_list_add: %p %llx many->many\n", spte, *spte);
desc = (struct pte_list_desc *)(rmap_head->val & ~1ul); desc = (struct pte_list_desc *)(rmap_head->val & ~1ul);
while (desc->sptes[PTE_LIST_EXT-1] && desc->more) { while (desc->sptes[PTE_LIST_EXT-1]) {
desc = desc->more;
count += PTE_LIST_EXT; count += PTE_LIST_EXT;
}
if (desc->sptes[PTE_LIST_EXT-1]) { if (!desc->more) {
desc->more = mmu_alloc_pte_list_desc(vcpu); desc->more = mmu_alloc_pte_list_desc(vcpu);
desc = desc->more; desc = desc->more;
break;
}
desc = desc->more;
} }
for (i = 0; desc->sptes[i]; ++i) for (i = 0; desc->sptes[i]; ++i)
++count; ++count;