hw/virtio/vhost-vsock-common.c - qemu - Git at Google

 /*
  * Parent class for vhost-vsock devices
  *
  * Copyright 2015-2020 Red Hat, Inc.
  *
  * This work is licensed under the terms of the GNU GPL, version 2 or
  * (at your option) any later version.  See the COPYING file in the
  * top-level directory.
  */

 #include "qemu/osdep.h"
 #include "standard-headers/linux/virtio_vsock.h"
 #include "qapi/error.h"
 #include "hw/virtio/virtio-access.h"
 #include "qemu/error-report.h"
 #include "hw/qdev-properties.h"
 #include "hw/virtio/vhost-vsock.h"
 #include "qemu/iov.h"
 #include "monitor/monitor.h"

 const int feature_bits[] = {
     VIRTIO_VSOCK_F_SEQPACKET,
     VHOST_INVALID_FEATURE_BIT
 };

 uint64_t vhost_vsock_common_get_features(VirtIODevice *vdev, uint64_t features,
                                          Error **errp)
 {
     VHostVSockCommon *vvc = VHOST_VSOCK_COMMON(vdev);

     if (vvc->seqpacket != ON_OFF_AUTO_OFF) {
         virtio_add_feature(&features, VIRTIO_VSOCK_F_SEQPACKET);
     }

     features = vhost_get_features(&vvc->vhost_dev, feature_bits, features);

     if (vvc->seqpacket == ON_OFF_AUTO_ON &&
         !virtio_has_feature(features, VIRTIO_VSOCK_F_SEQPACKET)) {
         error_setg(errp, "vhost-vsock backend doesn't support seqpacket");
     }

     return features;
 }

 int vhost_vsock_common_start(VirtIODevice *vdev)
 {
     VHostVSockCommon *vvc = VHOST_VSOCK_COMMON(vdev);
     BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
     int ret;
     int i;

     if (!k->set_guest_notifiers) {
         error_report("binding does not support guest notifiers");
         return -ENOSYS;
     }

     ret = vhost_dev_enable_notifiers(&vvc->vhost_dev, vdev);
     if (ret < 0) {
         error_report("Error enabling host notifiers: %d", -ret);
         return ret;
     }

     ret = k->set_guest_notifiers(qbus->parent, vvc->vhost_dev.nvqs, true);
     if (ret < 0) {
         error_report("Error binding guest notifier: %d", -ret);
         goto err_host_notifiers;
     }

     vvc->vhost_dev.acked_features = vdev->guest_features;
     ret = vhost_dev_start(&vvc->vhost_dev, vdev);
     if (ret < 0) {
         error_report("Error starting vhost: %d", -ret);
         goto err_guest_notifiers;
     }

     /*
      * guest_notifier_mask/pending not used yet, so just unmask
      * everything here.  virtio-pci will do the right thing by
      * enabling/disabling irqfd.
      */
     for (i = 0; i < vvc->vhost_dev.nvqs; i++) {
         vhost_virtqueue_mask(&vvc->vhost_dev, vdev, i, false);
     }

     return 0;

 err_guest_notifiers:
     k->set_guest_notifiers(qbus->parent, vvc->vhost_dev.nvqs, false);
 err_host_notifiers:
     vhost_dev_disable_notifiers(&vvc->vhost_dev, vdev);
     return ret;
 }

 void vhost_vsock_common_stop(VirtIODevice *vdev)
 {
     VHostVSockCommon *vvc = VHOST_VSOCK_COMMON(vdev);
     BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
     int ret;

     if (!k->set_guest_notifiers) {
         return;
     }

     vhost_dev_stop(&vvc->vhost_dev, vdev);

     ret = k->set_guest_notifiers(qbus->parent, vvc->vhost_dev.nvqs, false);
     if (ret < 0) {
         error_report("vhost guest notifier cleanup failed: %d", ret);
         return;
     }

     vhost_dev_disable_notifiers(&vvc->vhost_dev, vdev);
 }


 static void vhost_vsock_common_handle_output(VirtIODevice *vdev, VirtQueue *vq)
 {
     /* Do nothing */
 }

 static void vhost_vsock_common_guest_notifier_mask(VirtIODevice *vdev, int idx,
                                             bool mask)
 {
     VHostVSockCommon *vvc = VHOST_VSOCK_COMMON(vdev);

     vhost_virtqueue_mask(&vvc->vhost_dev, vdev, idx, mask);
 }

 static bool vhost_vsock_common_guest_notifier_pending(VirtIODevice *vdev,
                                                int idx)
 {
     VHostVSockCommon *vvc = VHOST_VSOCK_COMMON(vdev);

     return vhost_virtqueue_pending(&vvc->vhost_dev, idx);
 }

 static void vhost_vsock_common_send_transport_reset(VHostVSockCommon *vvc)
 {
     VirtQueueElement *elem;
     VirtQueue *vq = vvc->event_vq;
     struct virtio_vsock_event event = {
         .id = cpu_to_le32(VIRTIO_VSOCK_EVENT_TRANSPORT_RESET),
     };

     elem = virtqueue_pop(vq, sizeof(VirtQueueElement));
     if (!elem) {
         error_report("vhost-vsock missed transport reset event");
         return;
     }

     if (elem->out_num) {
         error_report("invalid vhost-vsock event virtqueue element with "
                      "out buffers");
         goto err;
     }

     if (iov_from_buf(elem->in_sg, elem->in_num, 0,
                      &event, sizeof(event)) != sizeof(event)) {
         error_report("vhost-vsock event virtqueue element is too short");
         goto err;
     }

     virtqueue_push(vq, elem, sizeof(event));
     virtio_notify(VIRTIO_DEVICE(vvc), vq);

     g_free(elem);
     return;

 err:
     virtqueue_detach_element(vq, elem, 0);
     g_free(elem);
 }

 static void vhost_vsock_common_post_load_timer_cleanup(VHostVSockCommon *vvc)
 {
     if (!vvc->post_load_timer) {
         return;
     }

     timer_free(vvc->post_load_timer);
     vvc->post_load_timer = NULL;
 }

 static void vhost_vsock_common_post_load_timer_cb(void *opaque)
 {
     VHostVSockCommon *vvc = opaque;

     vhost_vsock_common_post_load_timer_cleanup(vvc);
     vhost_vsock_common_send_transport_reset(vvc);
 }

 int vhost_vsock_common_pre_save(void *opaque)
 {
     VHostVSockCommon *vvc = opaque;

     /*
      * At this point, backend must be stopped, otherwise
      * it might keep writing to memory.
      */
     assert(!vvc->vhost_dev.started);

     return 0;
 }

 int vhost_vsock_common_post_load(void *opaque, int version_id)
 {
     VHostVSockCommon *vvc = opaque;
     VirtIODevice *vdev = VIRTIO_DEVICE(vvc);

     if (virtio_queue_get_addr(vdev, 2)) {
         /*
          * Defer transport reset event to a vm clock timer so that virtqueue
          * changes happen after migration has completed.
          */
         assert(!vvc->post_load_timer);
         vvc->post_load_timer =
             timer_new_ns(QEMU_CLOCK_VIRTUAL,
                          vhost_vsock_common_post_load_timer_cb,
                          vvc);
         timer_mod(vvc->post_load_timer, 1);
     }
     return 0;
 }

 void vhost_vsock_common_realize(VirtIODevice *vdev)
 {
     VHostVSockCommon *vvc = VHOST_VSOCK_COMMON(vdev);

     virtio_init(vdev, VIRTIO_ID_VSOCK, sizeof(struct virtio_vsock_config));

     /* Receive and transmit queues belong to vhost */
     vvc->recv_vq = virtio_add_queue(vdev, VHOST_VSOCK_QUEUE_SIZE,
                                       vhost_vsock_common_handle_output);
     vvc->trans_vq = virtio_add_queue(vdev, VHOST_VSOCK_QUEUE_SIZE,
                                        vhost_vsock_common_handle_output);

     /* The event queue belongs to QEMU */
     vvc->event_vq = virtio_add_queue(vdev, VHOST_VSOCK_QUEUE_SIZE,
                                        vhost_vsock_common_handle_output);

     vvc->vhost_dev.nvqs = ARRAY_SIZE(vvc->vhost_vqs);
     vvc->vhost_dev.vqs = vvc->vhost_vqs;

     vvc->post_load_timer = NULL;
 }

 void vhost_vsock_common_unrealize(VirtIODevice *vdev)
 {
     VHostVSockCommon *vvc = VHOST_VSOCK_COMMON(vdev);

     vhost_vsock_common_post_load_timer_cleanup(vvc);

     virtio_delete_queue(vvc->recv_vq);
     virtio_delete_queue(vvc->trans_vq);
     virtio_delete_queue(vvc->event_vq);
     virtio_cleanup(vdev);
 }

 static struct vhost_dev *vhost_vsock_common_get_vhost(VirtIODevice *vdev)
 {
     VHostVSockCommon *vvc = VHOST_VSOCK_COMMON(vdev);
     return &vvc->vhost_dev;
 }

 static Property vhost_vsock_common_properties[] = {
     DEFINE_PROP_ON_OFF_AUTO("seqpacket", VHostVSockCommon, seqpacket,
                             ON_OFF_AUTO_AUTO),
     DEFINE_PROP_END_OF_LIST(),
 };

 static void vhost_vsock_common_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(klass);
     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);

     device_class_set_props(dc, vhost_vsock_common_properties);
     set_bit(DEVICE_CATEGORY_MISC, dc->categories);
     vdc->guest_notifier_mask = vhost_vsock_common_guest_notifier_mask;
     vdc->guest_notifier_pending = vhost_vsock_common_guest_notifier_pending;
     vdc->get_vhost = vhost_vsock_common_get_vhost;
 }

 static const TypeInfo vhost_vsock_common_info = {
     .name = TYPE_VHOST_VSOCK_COMMON,
     .parent = TYPE_VIRTIO_DEVICE,
     .instance_size = sizeof(VHostVSockCommon),
     .class_init = vhost_vsock_common_class_init,
     .abstract = true,
 };

 static void vhost_vsock_common_register_types(void)
 {
     type_register_static(&vhost_vsock_common_info);
 }

 type_init(vhost_vsock_common_register_types)
	/*
	* Parent class for vhost-vsock devices
	*
	* Copyright 2015-2020 Red Hat, Inc.
	*
	* This work is licensed under the terms of the GNU GPL, version 2 or
	* (at your option) any later version. See the COPYING file in the
	* top-level directory.
	*/

	#include "qemu/osdep.h"
	#include "standard-headers/linux/virtio_vsock.h"
	#include "qapi/error.h"
	#include "hw/virtio/virtio-access.h"
	#include "qemu/error-report.h"
	#include "hw/qdev-properties.h"
	#include "hw/virtio/vhost-vsock.h"
	#include "qemu/iov.h"
	#include "monitor/monitor.h"

	const int feature_bits[] = {
	VIRTIO_VSOCK_F_SEQPACKET,
	VHOST_INVALID_FEATURE_BIT
	};

	uint64_t vhost_vsock_common_get_features(VirtIODevice *vdev, uint64_t features,
	Error **errp)
	{
	VHostVSockCommon *vvc = VHOST_VSOCK_COMMON(vdev);

	if (vvc->seqpacket != ON_OFF_AUTO_OFF) {
	virtio_add_feature(&features, VIRTIO_VSOCK_F_SEQPACKET);
	}

	features = vhost_get_features(&vvc->vhost_dev, feature_bits, features);

	if (vvc->seqpacket == ON_OFF_AUTO_ON &&
	!virtio_has_feature(features, VIRTIO_VSOCK_F_SEQPACKET)) {
	error_setg(errp, "vhost-vsock backend doesn't support seqpacket");
	}

	return features;
	}

	int vhost_vsock_common_start(VirtIODevice *vdev)
	{
	VHostVSockCommon *vvc = VHOST_VSOCK_COMMON(vdev);
	BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
	VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
	int ret;
	int i;

	if (!k->set_guest_notifiers) {
	error_report("binding does not support guest notifiers");
	return -ENOSYS;
	}

	ret = vhost_dev_enable_notifiers(&vvc->vhost_dev, vdev);
	if (ret < 0) {
	error_report("Error enabling host notifiers: %d", -ret);
	return ret;
	}

	ret = k->set_guest_notifiers(qbus->parent, vvc->vhost_dev.nvqs, true);
	if (ret < 0) {
	error_report("Error binding guest notifier: %d", -ret);
	goto err_host_notifiers;
	}

	vvc->vhost_dev.acked_features = vdev->guest_features;
	ret = vhost_dev_start(&vvc->vhost_dev, vdev);
	if (ret < 0) {
	error_report("Error starting vhost: %d", -ret);
	goto err_guest_notifiers;
	}

	/*
	* guest_notifier_mask/pending not used yet, so just unmask
	* everything here. virtio-pci will do the right thing by
	* enabling/disabling irqfd.
	*/
	for (i = 0; i < vvc->vhost_dev.nvqs; i++) {
	vhost_virtqueue_mask(&vvc->vhost_dev, vdev, i, false);
	}

	return 0;

	err_guest_notifiers:
	k->set_guest_notifiers(qbus->parent, vvc->vhost_dev.nvqs, false);
	err_host_notifiers:
	vhost_dev_disable_notifiers(&vvc->vhost_dev, vdev);
	return ret;
	}

	void vhost_vsock_common_stop(VirtIODevice *vdev)
	{
	VHostVSockCommon *vvc = VHOST_VSOCK_COMMON(vdev);
	BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
	VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
	int ret;

	if (!k->set_guest_notifiers) {
	return;
	}

	vhost_dev_stop(&vvc->vhost_dev, vdev);

	ret = k->set_guest_notifiers(qbus->parent, vvc->vhost_dev.nvqs, false);
	if (ret < 0) {
	error_report("vhost guest notifier cleanup failed: %d", ret);
	return;
	}

	vhost_dev_disable_notifiers(&vvc->vhost_dev, vdev);
	}


	static void vhost_vsock_common_handle_output(VirtIODevice vdev, VirtQueue vq)
	{
	/* Do nothing */
	}

	static void vhost_vsock_common_guest_notifier_mask(VirtIODevice *vdev, int idx,
	bool mask)
	{
	VHostVSockCommon *vvc = VHOST_VSOCK_COMMON(vdev);

	vhost_virtqueue_mask(&vvc->vhost_dev, vdev, idx, mask);
	}

	static bool vhost_vsock_common_guest_notifier_pending(VirtIODevice *vdev,
	int idx)
	{
	VHostVSockCommon *vvc = VHOST_VSOCK_COMMON(vdev);

	return vhost_virtqueue_pending(&vvc->vhost_dev, idx);
	}

	static void vhost_vsock_common_send_transport_reset(VHostVSockCommon *vvc)
	{
	VirtQueueElement *elem;
	VirtQueue *vq = vvc->event_vq;
	struct virtio_vsock_event event = {
	.id = cpu_to_le32(VIRTIO_VSOCK_EVENT_TRANSPORT_RESET),
	};

	elem = virtqueue_pop(vq, sizeof(VirtQueueElement));
	if (!elem) {
	error_report("vhost-vsock missed transport reset event");
	return;
	}

	if (elem->out_num) {
	error_report("invalid vhost-vsock event virtqueue element with "
	"out buffers");
	goto err;
	}

	if (iov_from_buf(elem->in_sg, elem->in_num, 0,
	&event, sizeof(event)) != sizeof(event)) {
	error_report("vhost-vsock event virtqueue element is too short");
	goto err;
	}

	virtqueue_push(vq, elem, sizeof(event));
	virtio_notify(VIRTIO_DEVICE(vvc), vq);

	g_free(elem);
	return;

	err:
	virtqueue_detach_element(vq, elem, 0);
	g_free(elem);
	}

	static void vhost_vsock_common_post_load_timer_cleanup(VHostVSockCommon *vvc)
	{
	if (!vvc->post_load_timer) {
	return;
	}

	timer_free(vvc->post_load_timer);
	vvc->post_load_timer = NULL;
	}

	static void vhost_vsock_common_post_load_timer_cb(void *opaque)
	{
	VHostVSockCommon *vvc = opaque;

	vhost_vsock_common_post_load_timer_cleanup(vvc);
	vhost_vsock_common_send_transport_reset(vvc);
	}

	int vhost_vsock_common_pre_save(void *opaque)
	{
	VHostVSockCommon *vvc = opaque;

	/*
	* At this point, backend must be stopped, otherwise
	* it might keep writing to memory.
	*/
	assert(!vvc->vhost_dev.started);

	return 0;
	}

	int vhost_vsock_common_post_load(void *opaque, int version_id)
	{
	VHostVSockCommon *vvc = opaque;
	VirtIODevice *vdev = VIRTIO_DEVICE(vvc);

	if (virtio_queue_get_addr(vdev, 2)) {
	/*
	* Defer transport reset event to a vm clock timer so that virtqueue
	* changes happen after migration has completed.
	*/
	assert(!vvc->post_load_timer);
	vvc->post_load_timer =
	timer_new_ns(QEMU_CLOCK_VIRTUAL,
	vhost_vsock_common_post_load_timer_cb,
	vvc);
	timer_mod(vvc->post_load_timer, 1);
	}
	return 0;
	}

	void vhost_vsock_common_realize(VirtIODevice *vdev)
	{
	VHostVSockCommon *vvc = VHOST_VSOCK_COMMON(vdev);

	virtio_init(vdev, VIRTIO_ID_VSOCK, sizeof(struct virtio_vsock_config));

	/* Receive and transmit queues belong to vhost */
	vvc->recv_vq = virtio_add_queue(vdev, VHOST_VSOCK_QUEUE_SIZE,
	vhost_vsock_common_handle_output);
	vvc->trans_vq = virtio_add_queue(vdev, VHOST_VSOCK_QUEUE_SIZE,
	vhost_vsock_common_handle_output);

	/* The event queue belongs to QEMU */
	vvc->event_vq = virtio_add_queue(vdev, VHOST_VSOCK_QUEUE_SIZE,
	vhost_vsock_common_handle_output);

	vvc->vhost_dev.nvqs = ARRAY_SIZE(vvc->vhost_vqs);
	vvc->vhost_dev.vqs = vvc->vhost_vqs;

	vvc->post_load_timer = NULL;
	}

	void vhost_vsock_common_unrealize(VirtIODevice *vdev)
	{
	VHostVSockCommon *vvc = VHOST_VSOCK_COMMON(vdev);

	vhost_vsock_common_post_load_timer_cleanup(vvc);

	virtio_delete_queue(vvc->recv_vq);
	virtio_delete_queue(vvc->trans_vq);
	virtio_delete_queue(vvc->event_vq);
	virtio_cleanup(vdev);
	}

	static struct vhost_dev vhost_vsock_common_get_vhost(VirtIODevice vdev)
	{
	VHostVSockCommon *vvc = VHOST_VSOCK_COMMON(vdev);
	return &vvc->vhost_dev;
	}

	static Property vhost_vsock_common_properties[] = {
	DEFINE_PROP_ON_OFF_AUTO("seqpacket", VHostVSockCommon, seqpacket,
	ON_OFF_AUTO_AUTO),
	DEFINE_PROP_END_OF_LIST(),
	};

	static void vhost_vsock_common_class_init(ObjectClass klass, void data)
	{
	DeviceClass *dc = DEVICE_CLASS(klass);
	VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);

	device_class_set_props(dc, vhost_vsock_common_properties);
	set_bit(DEVICE_CATEGORY_MISC, dc->categories);
	vdc->guest_notifier_mask = vhost_vsock_common_guest_notifier_mask;
	vdc->guest_notifier_pending = vhost_vsock_common_guest_notifier_pending;
	vdc->get_vhost = vhost_vsock_common_get_vhost;
	}

	static const TypeInfo vhost_vsock_common_info = {
	.name = TYPE_VHOST_VSOCK_COMMON,
	.parent = TYPE_VIRTIO_DEVICE,
	.instance_size = sizeof(VHostVSockCommon),
	.class_init = vhost_vsock_common_class_init,
	.abstract = true,
	};

	static void vhost_vsock_common_register_types(void)
	{
	type_register_static(&vhost_vsock_common_info);
	}

	type_init(vhost_vsock_common_register_types)