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authorAvi Kivity <avi@qumranet.com>2007-01-05 19:36:46 -0500
committerLinus Torvalds <torvalds@woody.osdl.org>2007-01-06 02:55:25 -0500
commit697fe2e24ac49f03a82f6cfe5d77f7a2122ff382 (patch)
tree26de8b1535ea7af9124e85985b37069e7d1fd604 /drivers/kvm
parenta436036baf331703b4d2c8e8a45f02c597bf6913 (diff)
[PATCH] KVM: MMU: Implement child shadow unlinking
When removing a page table, we must maintain the parent_pte field all child shadow page tables. Signed-off-by: Avi Kivity <avi@qumranet.com> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'drivers/kvm')
-rw-r--r--drivers/kvm/mmu.c42
1 files changed, 38 insertions, 4 deletions
diff --git a/drivers/kvm/mmu.c b/drivers/kvm/mmu.c
index 1484b7211717..7e20dbf4f84c 100644
--- a/drivers/kvm/mmu.c
+++ b/drivers/kvm/mmu.c
@@ -402,12 +402,21 @@ static void mmu_page_remove_parent_pte(struct kvm_mmu_page *page,
402 break; 402 break;
403 if (pte_chain->parent_ptes[i] != parent_pte) 403 if (pte_chain->parent_ptes[i] != parent_pte)
404 continue; 404 continue;
405 while (i + 1 < NR_PTE_CHAIN_ENTRIES) { 405 while (i + 1 < NR_PTE_CHAIN_ENTRIES
406 && pte_chain->parent_ptes[i + 1]) {
406 pte_chain->parent_ptes[i] 407 pte_chain->parent_ptes[i]
407 = pte_chain->parent_ptes[i + 1]; 408 = pte_chain->parent_ptes[i + 1];
408 ++i; 409 ++i;
409 } 410 }
410 pte_chain->parent_ptes[i] = NULL; 411 pte_chain->parent_ptes[i] = NULL;
412 if (i == 0) {
413 hlist_del(&pte_chain->link);
414 kfree(pte_chain);
415 if (hlist_empty(&page->parent_ptes)) {
416 page->multimapped = 0;
417 page->parent_pte = NULL;
418 }
419 }
411 return; 420 return;
412 } 421 }
413 BUG(); 422 BUG();
@@ -481,7 +490,30 @@ static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu,
481static void kvm_mmu_page_unlink_children(struct kvm_vcpu *vcpu, 490static void kvm_mmu_page_unlink_children(struct kvm_vcpu *vcpu,
482 struct kvm_mmu_page *page) 491 struct kvm_mmu_page *page)
483{ 492{
484 BUG(); 493 unsigned i;
494 u64 *pt;
495 u64 ent;
496
497 pt = __va(page->page_hpa);
498
499 if (page->role.level == PT_PAGE_TABLE_LEVEL) {
500 for (i = 0; i < PT64_ENT_PER_PAGE; ++i) {
501 if (pt[i] & PT_PRESENT_MASK)
502 rmap_remove(vcpu->kvm, &pt[i]);
503 pt[i] = 0;
504 }
505 return;
506 }
507
508 for (i = 0; i < PT64_ENT_PER_PAGE; ++i) {
509 ent = pt[i];
510
511 pt[i] = 0;
512 if (!(ent & PT_PRESENT_MASK))
513 continue;
514 ent &= PT64_BASE_ADDR_MASK;
515 mmu_page_remove_parent_pte(page_header(ent), &pt[i]);
516 }
485} 517}
486 518
487static void kvm_mmu_put_page(struct kvm_vcpu *vcpu, 519static void kvm_mmu_put_page(struct kvm_vcpu *vcpu,
@@ -489,8 +521,7 @@ static void kvm_mmu_put_page(struct kvm_vcpu *vcpu,
489 u64 *parent_pte) 521 u64 *parent_pte)
490{ 522{
491 mmu_page_remove_parent_pte(page, parent_pte); 523 mmu_page_remove_parent_pte(page, parent_pte);
492 if (page->role.level > PT_PAGE_TABLE_LEVEL) 524 kvm_mmu_page_unlink_children(vcpu, page);
493 kvm_mmu_page_unlink_children(vcpu, page);
494 hlist_del(&page->hash_link); 525 hlist_del(&page->hash_link);
495 list_del(&page->link); 526 list_del(&page->link);
496 list_add(&page->link, &vcpu->free_pages); 527 list_add(&page->link, &vcpu->free_pages);
@@ -511,6 +542,7 @@ static void kvm_mmu_zap_page(struct kvm_vcpu *vcpu,
511 struct kvm_pte_chain, link); 542 struct kvm_pte_chain, link);
512 parent_pte = chain->parent_ptes[0]; 543 parent_pte = chain->parent_ptes[0];
513 } 544 }
545 BUG_ON(!parent_pte);
514 kvm_mmu_put_page(vcpu, page, parent_pte); 546 kvm_mmu_put_page(vcpu, page, parent_pte);
515 *parent_pte = 0; 547 *parent_pte = 0;
516 } 548 }
@@ -530,6 +562,8 @@ static int kvm_mmu_unprotect_page(struct kvm_vcpu *vcpu, gfn_t gfn)
530 bucket = &vcpu->kvm->mmu_page_hash[index]; 562 bucket = &vcpu->kvm->mmu_page_hash[index];
531 hlist_for_each_entry_safe(page, node, n, bucket, hash_link) 563 hlist_for_each_entry_safe(page, node, n, bucket, hash_link)
532 if (page->gfn == gfn && !page->role.metaphysical) { 564 if (page->gfn == gfn && !page->role.metaphysical) {
565 pgprintk("%s: gfn %lx role %x\n", __FUNCTION__, gfn,
566 page->role.word);
533 kvm_mmu_zap_page(vcpu, page); 567 kvm_mmu_zap_page(vcpu, page);
534 r = 1; 568 r = 1;
535 } 569 }