In order to detecting spte remapping, we can simply check whether the spte has already been pointing to the pfn even if the spte is not the last spte, for middle spte is pointing to the kernel pfn which can not be mapped to userspace Signed-off-by: Xiao Guangrong <xiaoguangrong@xxxxxxxxxxxxxxxxxx> --- arch/x86/kvm/mmu.c | 28 +++++++--------------------- 1 files changed, 7 insertions(+), 21 deletions(-) diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index 8dca8af..a999755 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -2407,33 +2407,20 @@ static void mmu_set_spte(struct kvm_vcpu *vcpu, u64 *sptep, int write_fault, int *emulate, int level, gfn_t gfn, pfn_t pfn, bool speculative, bool host_writable) { - int was_rmapped = 0; - int rmap_count; + bool was_rmapped = false; pgprintk("%s: spte %llx access %x write_fault %d gfn %llx\n", __func__, *sptep, pt_access, write_fault, gfn); if (is_rmap_spte(*sptep)) { - /* - * If we overwrite a PTE page pointer with a 2MB PMD, unlink - * the parent of the now unreachable PTE. - */ - if (level > PT_PAGE_TABLE_LEVEL && - !is_large_pte(*sptep)) { - struct kvm_mmu_page *child; - u64 pte = *sptep; + if (pfn != spte_to_pfn(*sptep)) { + struct kvm_mmu_page *sp = page_header(__pa(sptep)); - child = page_header(pte & PT64_BASE_ADDR_MASK); - drop_parent_pte(child, sptep); - kvm_flush_remote_tlbs(vcpu->kvm); - } else if (pfn != spte_to_pfn(*sptep)) { - pgprintk("hfn old %llx new %llx\n", - spte_to_pfn(*sptep), pfn); - drop_spte(vcpu->kvm, sptep); - kvm_flush_remote_tlbs(vcpu->kvm); + if (mmu_page_zap_pte(vcpu->kvm, sp, sptep)) + kvm_flush_remote_tlbs(vcpu->kvm); } else - was_rmapped = 1; + was_rmapped = true; } if (set_spte(vcpu, sptep, pte_access, level, gfn, pfn, speculative, @@ -2456,8 +2443,7 @@ static void mmu_set_spte(struct kvm_vcpu *vcpu, u64 *sptep, if (is_shadow_present_pte(*sptep)) { if (!was_rmapped) { - rmap_count = rmap_add(vcpu, sptep, gfn); - if (rmap_count > RMAP_RECYCLE_THRESHOLD) + if (rmap_add(vcpu, sptep, gfn) > RMAP_RECYCLE_THRESHOLD) rmap_recycle(vcpu, sptep, gfn); } } -- 1.7.7.6 -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html