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/*
* 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 "linux/vhost.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 int vhost_kernel_memslots_limit(struct vhost_dev *dev)
{
int limit = 64;
char *s;
if (g_file_get_contents("/sys/module/vhost/parameters/max_mem_regions",
&s, NULL, NULL)) {
uint64_t val = g_ascii_strtoull(s, NULL, 10);
if (!((val == G_MAXUINT64 || !val) && errno)) {
return val;
}
error_report("ignoring invalid max_mem_regions value in vhost module:"
" %s", s);
}
return limit;
}
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,
.vhost_backend_memslots_limit = vhost_kernel_memslots_limit,
};
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;
}
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