qemu/hw/virtio/vhost-backend.c
Yuanhan Liu fc57fd9900 vhost: introduce vhost_backend_get_vq_index method
Minusing the idx with the base(dev->vq_index) for vhost-kernel, and
then adding it back for vhost-user doesn't seem right. Here introduces
a new method vhost_backend_get_vq_index() for getting the right vq
index for following vhost messages calls.

Suggested-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Reviewed-by: Jason Wang <jasowang@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Tested-by: Marcel Apfelbaum <marcel@redhat.com>
2015-09-24 16:27:53 +03:00

78 lines
1.8 KiB
C

/*
* vhost-backend
*
* Copyright (c) 2013 Virtual Open Systems Sarl.
*
* This work is licensed under the terms of the GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
*
*/
#include "hw/virtio/vhost.h"
#include "hw/virtio/vhost-backend.h"
#include "qemu/error-report.h"
#include <sys/ioctl.h>
static int vhost_kernel_call(struct vhost_dev *dev, unsigned long int request,
void *arg)
{
int fd = (uintptr_t) dev->opaque;
assert(dev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_KERNEL);
return ioctl(fd, request, arg);
}
static int vhost_kernel_init(struct vhost_dev *dev, void *opaque)
{
assert(dev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_KERNEL);
dev->opaque = opaque;
return 0;
}
static int vhost_kernel_cleanup(struct vhost_dev *dev)
{
int fd = (uintptr_t) dev->opaque;
assert(dev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_KERNEL);
return close(fd);
}
static int vhost_kernel_get_vq_index(struct vhost_dev *dev, int idx)
{
assert(idx >= dev->vq_index && idx < dev->vq_index + dev->nvqs);
return idx - dev->vq_index;
}
static const VhostOps kernel_ops = {
.backend_type = VHOST_BACKEND_TYPE_KERNEL,
.vhost_call = vhost_kernel_call,
.vhost_backend_init = vhost_kernel_init,
.vhost_backend_cleanup = vhost_kernel_cleanup,
.vhost_backend_get_vq_index = vhost_kernel_get_vq_index,
};
int vhost_set_backend_type(struct vhost_dev *dev, VhostBackendType backend_type)
{
int r = 0;
switch (backend_type) {
case VHOST_BACKEND_TYPE_KERNEL:
dev->vhost_ops = &kernel_ops;
break;
case VHOST_BACKEND_TYPE_USER:
dev->vhost_ops = &user_ops;
break;
default:
error_report("Unknown vhost backend type");
r = -1;
}
return r;
}