diff options
| author | Avi Kivity <avi@qumranet.com> | 2007-01-05 16:36:46 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.osdl.org> | 2007-01-05 23:55:25 -0800 |
| commit | 697fe2e24ac49f03a82f6cfe5d77f7a2122ff382 (patch) | |
| tree | 26de8b1535ea7af9124e85985b37069e7d1fd604 /drivers/kvm | |
| parent | a436036baf331703b4d2c8e8a45f02c597bf6913 (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.c | 42 |
1 files changed, 38 insertions, 4 deletions
diff --git a/drivers/kvm/mmu.c b/drivers/kvm/mmu.c index 1484b721171..7e20dbf4f84 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, 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_page(struct kvm_vcpu *vcpu, 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_vcpu *vcpu, 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_vcpu *vcpu, 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 kvm_vcpu *vcpu, gfn_t gfn) 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; } |