From e3c5e7ec9efe0ebd47fa812cc86f01c51905edf6 Mon Sep 17 00:00:00 2001 From: Avi Kivity Date: Thu, 11 Oct 2007 12:32:30 +0200 Subject: [PATCH] KVM: Move guest pte dirty bit management to the guest pagetable walker This is more consistent with the accessed bit management, and makes the dirty bit available earlier for other purposes. Signed-off-by: Avi Kivity --- drivers/kvm/mmu.c | 5 +++++ drivers/kvm/paging_tmpl.h | 31 ++++++++----------------------- 2 files changed, 13 insertions(+), 23 deletions(-) diff --git a/drivers/kvm/mmu.c b/drivers/kvm/mmu.c index d046ba8077..e6616a6c9c 100644 --- a/drivers/kvm/mmu.c +++ b/drivers/kvm/mmu.c @@ -199,6 +199,11 @@ static int is_writeble_pte(unsigned long pte) return pte & PT_WRITABLE_MASK; } +static int is_dirty_pte(unsigned long pte) +{ + return pte & PT_DIRTY_MASK; +} + static int is_io_pte(unsigned long pte) { return pte & PT_SHADOW_IO_MARK; diff --git a/drivers/kvm/paging_tmpl.h b/drivers/kvm/paging_tmpl.h index 8e1e4ca6ea..da36e48fd0 100644 --- a/drivers/kvm/paging_tmpl.h +++ b/drivers/kvm/paging_tmpl.h @@ -144,6 +144,10 @@ static int FNAME(walk_addr)(struct guest_walker *walker, if (walker->level == PT_PAGE_TABLE_LEVEL) { walker->gfn = (*ptep & PT_BASE_ADDR_MASK) >> PAGE_SHIFT; + if (write_fault && !is_dirty_pte(*ptep)) { + mark_page_dirty(vcpu->kvm, table_gfn); + *ptep |= PT_DIRTY_MASK; + } break; } @@ -153,6 +157,10 @@ static int FNAME(walk_addr)(struct guest_walker *walker, walker->gfn = (*ptep & PT_DIR_BASE_ADDR_MASK) >> PAGE_SHIFT; walker->gfn += PT_INDEX(addr, PT_PAGE_TABLE_LEVEL); + if (write_fault && !is_dirty_pte(*ptep)) { + mark_page_dirty(vcpu->kvm, table_gfn); + *ptep |= PT_DIRTY_MASK; + } break; } @@ -194,12 +202,6 @@ err: return 0; } -static void FNAME(mark_pagetable_dirty)(struct kvm *kvm, - struct guest_walker *walker) -{ - mark_page_dirty(kvm, walker->table_gfn[walker->level - 1]); -} - static void FNAME(set_pte_common)(struct kvm_vcpu *vcpu, u64 *shadow_pte, gpa_t gaddr, @@ -221,23 +223,6 @@ static void FNAME(set_pte_common)(struct kvm_vcpu *vcpu, __FUNCTION__, *shadow_pte, (u64)gpte, access_bits, write_fault, user_fault, gfn); - if (write_fault && !dirty) { - pt_element_t *guest_ent, *tmp = NULL; - - if (walker->ptep) - guest_ent = walker->ptep; - else { - tmp = kmap_atomic(walker->page, KM_USER0); - guest_ent = &tmp[walker->index]; - } - - *guest_ent |= PT_DIRTY_MASK; - if (!walker->ptep) - kunmap_atomic(tmp, KM_USER0); - dirty = 1; - FNAME(mark_pagetable_dirty)(vcpu->kvm, walker); - } - /* * We don't set the accessed bit, since we sometimes want to see * whether the guest actually used the pte (in order to detect -- 2.39.5