qemu/include/hw/virtio/dataplane/vring.h
Stefan Hajnoczi f897bf751f virtio-blk: embed VirtQueueElement in VirtIOBlockReq
The memory allocation between hw/block/virtio-blk.c,
hw/block/dataplane/virtio-blk.c, and hw/virtio/dataplane/vring.c is
messy.  Structs are allocated in different files than they are freed in.
This is risky and makes memory leaks easier.

Embed VirtQueueElement in VirtIOBlockReq to reduce the amount of memory
allocation we need to juggle.  This also makes vring.c and virtio.c
slightly more similar.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-07-14 12:03:20 +02:00

60 lines
1.9 KiB
C

/* 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 */