qemu-e2k/hw/virtio/vhost-shadow-virtqueue.h
Eugenio Pérez 495fe3a787 vhost: Track descriptor chain in private at SVQ
The device could have access to modify them, and it definitely have
access when we implement packed vq. Harden SVQ maintaining a private
copy of the descriptor chain. Other fields like buffer addresses are
already maintained sepparatedly.

Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
Message-Id: <20220512175747.142058-2-eperezma@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2022-05-13 07:57:26 -04:00

94 lines
2.7 KiB
C

/*
* vhost shadow virtqueue
*
* SPDX-FileCopyrightText: Red Hat, Inc. 2021
* SPDX-FileContributor: Author: Eugenio Pérez <eperezma@redhat.com>
*
* SPDX-License-Identifier: GPL-2.0-or-later
*/
#ifndef VHOST_SHADOW_VIRTQUEUE_H
#define VHOST_SHADOW_VIRTQUEUE_H
#include "qemu/event_notifier.h"
#include "hw/virtio/virtio.h"
#include "standard-headers/linux/vhost_types.h"
#include "hw/virtio/vhost-iova-tree.h"
/* Shadow virtqueue to relay notifications */
typedef struct VhostShadowVirtqueue {
/* Shadow vring */
struct vring vring;
/* Shadow kick notifier, sent to vhost */
EventNotifier hdev_kick;
/* Shadow call notifier, sent to vhost */
EventNotifier hdev_call;
/*
* Borrowed virtqueue's guest to host notifier. To borrow it in this event
* notifier allows to recover the VhostShadowVirtqueue from the event loop
* easily. If we use the VirtQueue's one, we don't have an easy way to
* retrieve VhostShadowVirtqueue.
*
* So shadow virtqueue must not clean it, or we would lose VirtQueue one.
*/
EventNotifier svq_kick;
/* Guest's call notifier, where the SVQ calls guest. */
EventNotifier svq_call;
/* Virtio queue shadowing */
VirtQueue *vq;
/* Virtio device */
VirtIODevice *vdev;
/* IOVA mapping */
VhostIOVATree *iova_tree;
/* Map for use the guest's descriptors */
VirtQueueElement **ring_id_maps;
/* Next VirtQueue element that guest made available */
VirtQueueElement *next_guest_avail_elem;
/*
* Backup next field for each descriptor so we can recover securely, not
* needing to trust the device access.
*/
uint16_t *desc_next;
/* Next head to expose to the device */
uint16_t shadow_avail_idx;
/* Next free descriptor */
uint16_t free_head;
/* Last seen used idx */
uint16_t shadow_used_idx;
/* Next head to consume from the device */
uint16_t last_used_idx;
} VhostShadowVirtqueue;
bool vhost_svq_valid_features(uint64_t features, Error **errp);
void vhost_svq_set_svq_kick_fd(VhostShadowVirtqueue *svq, int svq_kick_fd);
void vhost_svq_set_svq_call_fd(VhostShadowVirtqueue *svq, int call_fd);
void vhost_svq_get_vring_addr(const VhostShadowVirtqueue *svq,
struct vhost_vring_addr *addr);
size_t vhost_svq_driver_area_size(const VhostShadowVirtqueue *svq);
size_t vhost_svq_device_area_size(const VhostShadowVirtqueue *svq);
void vhost_svq_start(VhostShadowVirtqueue *svq, VirtIODevice *vdev,
VirtQueue *vq);
void vhost_svq_stop(VhostShadowVirtqueue *svq);
VhostShadowVirtqueue *vhost_svq_new(VhostIOVATree *iova_tree);
void vhost_svq_free(gpointer vq);
G_DEFINE_AUTOPTR_CLEANUP_FUNC(VhostShadowVirtqueue, vhost_svq_free);
#endif