diff options
| -rw-r--r-- | drivers/kvm/mmu.c | 19 |
1 files changed, 17 insertions, 2 deletions
diff --git a/drivers/kvm/mmu.c b/drivers/kvm/mmu.c index 53c3643038bb..50b1432dceee 100644 --- a/drivers/kvm/mmu.c +++ b/drivers/kvm/mmu.c @@ -954,21 +954,36 @@ void kvm_mmu_pre_write(struct kvm_vcpu *vcpu, gpa_t gpa, int bytes) gfn_t gfn = gpa >> PAGE_SHIFT; struct kvm_mmu_page *page; struct kvm_mmu_page *child; - struct hlist_node *node; + struct hlist_node *node, *n; struct hlist_head *bucket; unsigned index; u64 *spte; u64 pte; unsigned offset = offset_in_page(gpa); + unsigned pte_size; unsigned page_offset; + unsigned misaligned; int level; pgprintk("%s: gpa %llx bytes %d\n", __FUNCTION__, gpa, bytes); index = kvm_page_table_hashfn(gfn) % KVM_NUM_MMU_PAGES; bucket = &vcpu->kvm->mmu_page_hash[index]; - hlist_for_each_entry(page, node, bucket, hash_link) { + hlist_for_each_entry_safe(page, node, n, bucket, hash_link) { if (page->gfn != gfn || page->role.metaphysical) continue; + pte_size = page->role.glevels == PT32_ROOT_LEVEL ? 4 : 8; + misaligned = (offset ^ (offset + bytes - 1)) & ~(pte_size - 1); + if (misaligned) { + /* + * Misaligned accesses are too much trouble to fix + * up; also, they usually indicate a page is not used + * as a page table. + */ + pgprintk("misaligned: gpa %llx bytes %d role %x\n", + gpa, bytes, page->role.word); + kvm_mmu_zap_page(vcpu, page); + continue; + } page_offset = offset; level = page->role.level; if (page->role.glevels == PT32_ROOT_LEVEL) { |