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/* Copyright 2012 Red Hat, Inc. and/or its affiliates
* Copyright IBM, Corp. 2012
*
* Based on Linux 2.6.39 vhost code:
* Copyright (C) 2009 Red Hat, Inc.
* Copyright (C) 2006 Rusty Russell IBM Corporation
*
* Author: Michael S. Tsirkin <mst@redhat.com>
* Stefan Hajnoczi <stefanha@redhat.com>
*
* Inspiration, some code, and most witty comments come from
* Documentation/virtual/lguest/lguest.c, by Rusty Russell
*
* This work is licensed under the terms of the GNU GPL, version 2.
*/
#ifndef VRING_H
#define VRING_H
#include <linux/virtio_ring.h>
#include "qemu-common.h"
#include "hw/virtio/virtio.h"
typedef struct {
MemoryRegion *mr; /* memory region containing the vring */
struct vring vr; /* virtqueue vring mapped to host memory */
uint16_t last_avail_idx; /* last processed avail ring index */
uint16_t last_used_idx; /* last processed used ring index */
uint16_t signalled_used; /* EVENT_IDX state */
bool signalled_used_valid;
bool broken; /* was there a fatal error? */
} Vring;
static inline unsigned int vring_get_num(Vring *vring)
{
return vring->vr.num;
}
/* Are there more descriptors available? */
static inline bool vring_more_avail(Vring *vring)
{
return vring->vr.avail->idx != vring->last_avail_idx;
}
/* Fail future vring_pop() and vring_push() calls until reset */
static inline void vring_set_broken(Vring *vring)
{
vring->broken = true;
}
bool vring_setup(Vring *vring, VirtIODevice *vdev, int n);
void vring_teardown(Vring *vring, VirtIODevice *vdev, int n);
void vring_disable_notification(VirtIODevice *vdev, Vring *vring);
bool vring_enable_notification(VirtIODevice *vdev, Vring *vring);
bool vring_should_notify(VirtIODevice *vdev, Vring *vring);
int vring_pop(VirtIODevice *vdev, Vring *vring, VirtQueueElement *elem);
void vring_push(Vring *vring, VirtQueueElement *elem, int len);
#endif /* VRING_H */
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