passt/virtio.h
Laurent Vivier 45b1403f42 vhost-user: introduce virtio API
Add virtio.c and virtio.h that define the functions needed
to manage virtqueues.

Signed-off-by: Laurent Vivier <lvivier@redhat.com>
2024-03-12 11:54:26 +01:00

121 lines
2.8 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
//
/* come parts copied from QEMU subprojects/libvhost-user/libvhost-user.h */
#ifndef VIRTIO_H
#define VIRTIO_H
#include <stdbool.h>
#include <linux/vhost_types.h>
#define VIRTQUEUE_MAX_SIZE 1024
#define vu_panic(vdev, ...) \
do { \
(vdev)->broken = true; \
err( __VA_ARGS__ ); \
} while (0)
typedef struct VuRing {
unsigned int num;
struct vring_desc *desc;
struct vring_avail *avail;
struct vring_used *used;
uint64_t log_guest_addr;
uint32_t flags;
} VuRing;
typedef struct VuVirtq {
VuRing vring;
/* Next head to pop */
uint16_t last_avail_idx;
/* Last avail_idx read from VQ. */
uint16_t shadow_avail_idx;
uint16_t used_idx;
/* Last used index value we have signalled on */
uint16_t signalled_used;
/* Last used index value we have signalled on */
bool signalled_used_valid;
bool notification;
unsigned int inuse;
int call_fd;
int kick_fd;
int err_fd;
unsigned int enable;
bool started;
/* Guest addresses of our ring */
struct vhost_vring_addr vra;
} VuVirtq;
typedef struct VuDevRegion {
uint64_t gpa;
uint64_t size;
uint64_t qva;
uint64_t mmap_offset;
uint64_t mmap_addr;
} VuDevRegion;
#define VHOST_USER_MAX_QUEUES 2
/*
* Set a reasonable maximum number of ram slots, which will be supported by
* any architecture.
*/
#define VHOST_USER_MAX_RAM_SLOTS 32
typedef struct VuDev {
uint32_t nregions;
VuDevRegion regions[VHOST_USER_MAX_RAM_SLOTS];
VuVirtq vq[VHOST_USER_MAX_QUEUES];
uint64_t features;
uint64_t protocol_features;
bool broken;
int hdrlen;
} VuDev;
typedef struct VuVirtqElement {
unsigned int index;
unsigned int out_num;
unsigned int in_num;
struct iovec *in_sg;
struct iovec *out_sg;
} VuVirtqElement;
static inline bool has_feature(uint64_t features, unsigned int fbit)
{
return !!(features & (1ULL << fbit));
}
static inline bool vu_has_feature(VuDev *vdev, unsigned int fbit)
{
return has_feature(vdev->features, fbit);
}
static inline bool vu_has_protocol_feature(VuDev *vdev, unsigned int fbit)
{
return has_feature(vdev->protocol_features, fbit);
}
bool vu_queue_empty(VuDev *dev, VuVirtq *vq);
void vu_queue_notify(VuDev *dev, VuVirtq *vq);
void *vu_queue_pop(VuDev *dev, VuVirtq *vq, size_t sz, unsigned char *buffer);
void vu_queue_detach_element(VuDev *dev, VuVirtq *vq, unsigned int index, size_t len);
void vu_queue_unpop(VuDev *dev, VuVirtq *vq, unsigned int index, size_t len);
bool vu_queue_rewind(VuDev *dev, VuVirtq *vq, unsigned int num);
void vu_queue_fill_by_index(VuDev *dev, VuVirtq *vq, unsigned int index,
unsigned int len, unsigned int idx);
void vu_queue_fill(VuDev *dev, VuVirtq *vq, VuVirtqElement *elem, unsigned int len,
unsigned int idx);
void vu_queue_flush(VuDev *dev, VuVirtq *vq, unsigned int count);
void vu_queue_push(VuDev *dev, VuVirtq *vq, VuVirtqElement *elem, unsigned int len);
#endif /* VIRTIO_H */