vm: add vm-controller object

include/kernel/syscall.h

@@ -176,6 +176,10 @@ extern kern_status_t sys_msg_write(
 	size_t nr_in,
 	size_t *nr_written);
 
+extern kern_status_t sys_kern_object_wait(
+	kern_wait_item_t *items,
+	size_t nr_items);
+
 extern virt_addr_t syscall_get_function(unsigned int sysid);
 
 #endif

include/kernel/vm-controller.h

@@ -0,0 +1,68 @@
+#ifndef KERNEL_VM_CONTROLLER_H_
+#define KERNEL_VM_CONTROLLER_H_
+
+#include <kernel/locks.h>
+#include <kernel/object.h>
+#include <mango/types.h>
+
+struct thread;
+struct equeue;
+struct vm_object;
+
+enum page_request_status {
+	PAGE_REQUEST_PENDING = 0,
+	PAGE_REQUEST_IN_PROGRESS,
+	PAGE_REQUEST_COMPLETE,
+};
+
+struct vm_controller {
+	struct object vc_base;
+	/* tree of struct vm_objects bound to this controller, keyed with the
+	 * vm_key_t specified when the object(s) were created. */
+	struct btree vc_objects;
+	/* tree of pending page requests */
+	struct btree vc_requests;
+};
+
+struct page_request {
+	uint64_t req_id;
+	enum page_request_status req_status;
+	kern_status_t req_result;
+	struct vm_object *req_object;
+	struct thread *req_sender;
+	struct btree_node req_node;
+	off_t req_offset;
+	size_t req_length;
+};
+
+extern kern_status_t vm_controller_type_init(void);
+extern struct vm_controller *vm_controller_cast(struct object *obj);
+
+extern struct vm_controller *vm_controller_create(void);
+
+extern kern_status_t vm_controller_recv(
+	struct vm_controller *ctrl,
+	equeue_packet_page_request_t *out);
+extern kern_status_t vm_controller_recv_async(
+	struct vm_controller *ctrl,
+	struct equeue *eq);
+
+extern kern_status_t vm_controller_create_object(
+	struct vm_controller *ctrl,
+	const char *name,
+	size_t name_len,
+	equeue_key_t key,
+	size_t data_len,
+	vm_prot_t prot,
+	struct vm_object **out);
+extern kern_status_t vm_controller_detach_object(
+	struct vm_controller *ctrl,
+	struct vm_object *vmo);
+
+extern kern_status_t vm_controller_send_request(
+	struct vm_controller *ctrl,
+	struct page_request *req);
+
+DEFINE_OBJECT_LOCK_FUNCTION(vm_controller, vc_base)
+
+#endif

libmango/include-user/mango/vm.h

@@ -77,4 +77,29 @@ extern kern_status_t vm_region_unmap_relative(
 	off_t offset,
 	size_t length);
 
+extern kern_status_t vm_controller_create(kern_handle_t *out);
+extern kern_status_t vm_controller_recv(
+	kern_handle_t ctrl,
+	equeue_packet_page_request_t *out);
+extern kern_status_t vm_controller_recv_async(
+	kern_handle_t ctrl,
+	kern_handle_t eq);
+extern kern_status_t vm_controller_create_object(
+	kern_handle_t ctrl,
+	const char *name,
+	size_t name_len,
+	size_t data_len,
+	vm_prot_t prot,
+	kern_handle_t *out);
+extern kern_status_t vm_controller_detach_object(
+	kern_handle_t ctrl,
+	kern_handle_t vmo);
+extern kern_status_t vm_controller_supply_pages(
+	kern_handle_t ctrl,
+	kern_handle_t dst_vmo,
+	off_t dst_offset,
+	kern_handle_t src_vmo,
+	off_t src_offset,
+	size_t length);
+
 #endif

vm/vm-controller.c

@@ -0,0 +1,112 @@
+#include <kernel/sched.h>
+#include <kernel/thread.h>
+#include <kernel/util.h>
+#include <kernel/vm-controller.h>
+
+kern_status_t vm_controller_type_init(void)
+{
+	return KERN_UNIMPLEMENTED;
+}
+
+struct vm_controller *vm_controller_cast(struct object *obj)
+{
+	return NULL;
+}
+
+struct vm_controller *vm_controller_create(void)
+{
+	return NULL;
+}
+
+kern_status_t vm_controller_create_object(
+	struct vm_controller *ctrl,
+	const char *name,
+	size_t name_len,
+	equeue_key_t key,
+	size_t data_len,
+	vm_prot_t prot,
+	struct vm_object **out)
+{
+	return KERN_UNIMPLEMENTED;
+}
+
+kern_status_t vm_controller_detach_object(
+	struct vm_controller *ctrl,
+	struct vm_object *vmo)
+{
+	return KERN_UNIMPLEMENTED;
+}
+
+static kern_status_t try_enqueue(struct btree *tree, struct page_request *req)
+{
+	if (!tree->b_root) {
+		tree->b_root = &req->req_node;
+		btree_insert_fixup(tree, &req->req_node);
+		return true;
+	}
+
+	struct btree_node *cur = tree->b_root;
+	while (1) {
+		struct page_request *cur_node
+			= BTREE_CONTAINER(struct page_request, req_node, cur);
+		struct btree_node *next = NULL;
+
+		if (req->req_id > cur_node->req_id) {
+			next = btree_right(cur);
+
+			if (!next) {
+				btree_put_right(cur, &req->req_node);
+				break;
+			}
+		} else if (req->req_id < cur_node->req_id) {
+			next = btree_left(cur);
+
+			if (!next) {
+				btree_put_left(cur, &req->req_node);
+				break;
+			}
+		} else {
+			return false;
+		}
+
+		cur = next;
+	}
+
+	btree_insert_fixup(tree, &req->req_node);
+	return true;
+}
+
+static void wait_for_reply(
+	struct vm_controller *ctrl,
+	struct page_request *req,
+	unsigned long *lock_flags)
+{
+	struct wait_item waiter;
+	struct thread *self = current_thread();
+
+	wait_item_init(&waiter, self);
+	for (;;) {
+		self->tr_state = THREAD_SLEEPING;
+		if (req->req_status == PAGE_REQUEST_COMPLETE) {
+			break;
+		}
+
+		vm_controller_unlock_irqrestore(ctrl, *lock_flags);
+		schedule(SCHED_NORMAL);
+		vm_controller_lock_irqsave(ctrl, lock_flags);
+	}
+
+	self->tr_state = THREAD_READY;
+}
+
+kern_status_t vm_controller_send_request(
+	struct vm_controller *ctrl,
+	struct page_request *req)
+{
+	fill_random(&req->req_id, sizeof req->req_id);
+	while (!try_enqueue(&ctrl->vc_requests, req)) {
+		req->req_id++;
+	}
+
+	return KERN_OK;
+}