> -----Original Message----- > From: kvm-owner@xxxxxxxxxxxxxxx [mailto:kvm-owner@xxxxxxxxxxxxxxx] On > Behalf Of Christoffer Dall > Sent: Monday, October 01, 2012 6:11 PM > To: kvm@xxxxxxxxxxxxxxx; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; > kvmarm@xxxxxxxxxxxxxxxxxxxxx > Cc: Marc Zyngier > Subject: [PATCH v2 06/14] KVM: ARM: Memory virtualization setup > > +static void stage2_set_pte(struct kvm *kvm, struct kvm_mmu_memory_cache > *cache, > + phys_addr_t addr, const pte_t *new_pte) { > + pgd_t *pgd; > + pud_t *pud; > + pmd_t *pmd; > + pte_t *pte, old_pte; > + > + /* Create 2nd stage page table mapping - Level 1 */ > + pgd = kvm->arch.pgd + pgd_index(addr); > + pud = pud_offset(pgd, addr); > + if (pud_none(*pud)) { > + if (!cache) > + return; /* ignore calls from kvm_set_spte_hva */ > + pmd = mmu_memory_cache_alloc(cache); > + pud_populate(NULL, pud, pmd); > + pmd += pmd_index(addr); > + get_page(virt_to_page(pud)); > + } else > + pmd = pmd_offset(pud, addr); > + > + /* Create 2nd stage page table mapping - Level 2 */ > + if (pmd_none(*pmd)) { > + if (!cache) > + return; /* ignore calls from kvm_set_spte_hva */ > + pte = mmu_memory_cache_alloc(cache); > + clean_pte_table(pte); > + pmd_populate_kernel(NULL, pmd, pte); > + pte += pte_index(addr); > + get_page(virt_to_page(pmd)); > + } else > + pte = pte_offset_kernel(pmd, addr); > + > + /* Create 2nd stage page table mapping - Level 3 */ > + old_pte = *pte; > + set_pte_ext(pte, *new_pte, 0); > + if (pte_present(old_pte)) > + __kvm_tlb_flush_vmid(kvm); > + else > + get_page(virt_to_page(pte)); > +} I'm not sure about the 3-level page table, but isn't it necessary to clean the page table for 2nd level? There are two mmu_memory_cache_alloc calls. One has following clean_pte_table and the other doesn't have. And why do you ignore calls from kvm_set_spte_hva? It is supposed to happen when host moves the page, right? Then you ignore the case because it can be handled later when fault actually happens? Is there any other reason that I miss? _______________________________________________ kvmarm mailing list kvmarm@xxxxxxxxxxxxxxxxxxxxx https://lists.cs.columbia.edu/cucslists/listinfo/kvmarm
