Commit e3c5e7ec authored by Avi Kivity's avatar Avi Kivity
Browse files

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: default avatarAvi Kivity <avi@qumranet.com>
parent 4a4c9924

drivers/kvm/mmu.c

+5 −0
Original line number Diff line number Diff line
@@ -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;

drivers/kvm/paging_tmpl.h

+8 −23
Original line number Diff line number Diff line
@@ -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 @@ static int FNAME(walk_addr)(struct guest_walker *walker, 
	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