The patch titled KVM: MMU: Implement child shadow unlinking has been added to the -mm tree. Its filename is kvm-mmu-implement-child-shadow-unlinking.patch See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find out what to do about this ------------------------------------------------------ Subject: KVM: MMU: Implement child shadow unlinking From: Avi Kivity <avi@xxxxxxxxxxxx> When removing a page table, we must maintain the parent_pte field all child shadow page tables. Signed-off-by: Avi Kivity <avi@xxxxxxxxxxxx> Acked-by: Ingo Molnar <mingo@xxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxx> --- drivers/kvm/mmu.c | 42 ++++++++++++++++++++++++++++++++++++++---- 1 files changed, 38 insertions(+), 4 deletions(-) diff -puN drivers/kvm/mmu.c~kvm-mmu-implement-child-shadow-unlinking drivers/kvm/mmu.c --- a/drivers/kvm/mmu.c~kvm-mmu-implement-child-shadow-unlinking +++ a/drivers/kvm/mmu.c @@ -402,12 +402,21 @@ static void mmu_page_remove_parent_pte(s break; if (pte_chain->parent_ptes[i] != parent_pte) continue; - while (i + 1 < NR_PTE_CHAIN_ENTRIES) { + while (i + 1 < NR_PTE_CHAIN_ENTRIES + && pte_chain->parent_ptes[i + 1]) { pte_chain->parent_ptes[i] = pte_chain->parent_ptes[i + 1]; ++i; } pte_chain->parent_ptes[i] = NULL; + if (i == 0) { + hlist_del(&pte_chain->link); + kfree(pte_chain); + if (hlist_empty(&page->parent_ptes)) { + page->multimapped = 0; + page->parent_pte = NULL; + } + } return; } BUG(); @@ -481,7 +490,30 @@ static struct kvm_mmu_page *kvm_mmu_get_ static void kvm_mmu_page_unlink_children(struct kvm_vcpu *vcpu, struct kvm_mmu_page *page) { - BUG(); + unsigned i; + u64 *pt; + u64 ent; + + pt = __va(page->page_hpa); + + if (page->role.level == PT_PAGE_TABLE_LEVEL) { + for (i = 0; i < PT64_ENT_PER_PAGE; ++i) { + if (pt[i] & PT_PRESENT_MASK) + rmap_remove(vcpu->kvm, &pt[i]); + pt[i] = 0; + } + return; + } + + for (i = 0; i < PT64_ENT_PER_PAGE; ++i) { + ent = pt[i]; + + pt[i] = 0; + if (!(ent & PT_PRESENT_MASK)) + continue; + ent &= PT64_BASE_ADDR_MASK; + mmu_page_remove_parent_pte(page_header(ent), &pt[i]); + } } static void kvm_mmu_put_page(struct kvm_vcpu *vcpu, @@ -489,8 +521,7 @@ static void kvm_mmu_put_page(struct kvm_ u64 *parent_pte) { mmu_page_remove_parent_pte(page, parent_pte); - if (page->role.level > PT_PAGE_TABLE_LEVEL) - kvm_mmu_page_unlink_children(vcpu, page); + kvm_mmu_page_unlink_children(vcpu, page); hlist_del(&page->hash_link); list_del(&page->link); list_add(&page->link, &vcpu->free_pages); @@ -511,6 +542,7 @@ static void kvm_mmu_zap_page(struct kvm_ struct kvm_pte_chain, link); parent_pte = chain->parent_ptes[0]; } + BUG_ON(!parent_pte); kvm_mmu_put_page(vcpu, page, parent_pte); *parent_pte = 0; } @@ -530,6 +562,8 @@ static int kvm_mmu_unprotect_page(struct bucket = &vcpu->kvm->mmu_page_hash[index]; hlist_for_each_entry_safe(page, node, n, bucket, hash_link) if (page->gfn == gfn && !page->role.metaphysical) { + pgprintk("%s: gfn %lx role %x\n", __FUNCTION__, gfn, + page->role.word); kvm_mmu_zap_page(vcpu, page); r = 1; } _ Patches currently in -mm which might be from avi@xxxxxxxxxxxx are kvm-fix-gfp_kernel-alloc-in-atomic-section-bug.patch kvm-use-raw_smp_processor_id-instead-of-smp_processor_id-where-applicable.patch kvm-recover-after-an-arch-module-load-failure.patch kvm-improve-interrupt-response.patch kvm-prevent-stale-bits-in-cr0-and-cr4.patch kvm-mmu-implement-simple-reverse-mapping.patch kvm-mmu-teach-the-page-table-walker-to-track-guest-page-table-gfns.patch kvm-mmu-load-the-pae-pdptrs-on-cr3-change-like-the-processor-does.patch kvm-mmu-fold-fetch_guest-into-init_walker.patch kvm-mu-special-treatment-for-shadow-pae-root-pages.patch kvm-mmu-use-the-guest-pdptrs-instead-of-mapping-cr3-in-pae-mode.patch kvm-mmu-make-the-shadow-page-tables-also-special-case-pae.patch kvm-mmu-make-kvm_mmu_alloc_page-return-a-kvm_mmu_page-pointer.patch kvm-mmu-shadow-page-table-caching.patch kvm-mmu-write-protect-guest-pages-when-a-shadow-is-created-for-them.patch kvm-mmu-let-the-walker-extract-the-target-page-gfn-from-the-pte.patch kvm-mmu-support-emulated-writes-into-ram.patch kvm-mmu-zap-shadow-page-table-entries-on-writes-to-guest-page-tables.patch kvm-mmu-if-emulating-an-instruction-fails-try-unprotecting-the-page.patch kvm-mmu-implement-child-shadow-unlinking.patch kvm-mmu-kvm_mmu_put_page-only-removes-one-link-to-the-page.patch kvm-mmu-oom-handling.patch kvm-mmu-remove-invlpg-interception.patch kvm-mmu-remove-release_pt_page_64.patch kvm-mmu-handle-misaligned-accesses-to-write-protected-guest-page-tables.patch kvm-mmu-ove-is_empty_shadow_page-above-kvm_mmu_free_page.patch kvm-mmu-ensure-freed-shadow-pages-are-clean.patch kvm-mmu-if-an-empty-shadow-page-is-not-empty-report-more-info.patch kvm-mmu-page-table-write-flood-protection.patch kvm-mmu-never-free-a-shadow-page-actively-serving-as-a-root.patch kvm-mmu-fix-cmpxchg8b-emulation.patch kvm-mmu-treat-user-mode-faults-as-a-hint-that-a-page-is-no-longer-a-page-table.patch kvm-mmu-free-pages-on-kvm-destruction.patch kvm-mmu-replace-atomic-allocations-by-preallocated-objects.patch kvm-mmu-detect-oom-conditions-and-propagate-error-to-userspace.patch kvm-mmu-flush-guest-tlb-when-reducing-permissions-on-a-pte.patch kvm-mmu-destroy-mmu-while-we-still-have-a-vcpu-left.patch kvm-mmu-add-audit-code-to-check-mappings-etc-are-correct.patch - To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html