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Diffstat (limited to 'virtio.h')
| -rw-r--r-- | virtio.h | 183 |
1 files changed, 183 insertions, 0 deletions
diff --git a/virtio.h b/virtio.h new file mode 100644 index 0000000..94efeb0 --- /dev/null +++ b/virtio.h @@ -0,0 +1,183 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * virtio API, vring and virtqueue functions definition + * + * Copyright Red Hat + * Author: Laurent Vivier <lvivier@redhat.com> + */ + +#ifndef VIRTIO_H +#define VIRTIO_H + +#include <stdbool.h> +#include <linux/vhost_types.h> + +/* Maximum size of a virtqueue */ +#define VIRTQUEUE_MAX_SIZE 1024 + +/** + * struct vu_ring - Virtqueue rings + * @num: Size of the queue + * @desc: Descriptor ring + * @avail: Available ring + * @used: Used ring + * @log_guest_addr: Guest address for logging + * @flags: Vring flags + * VHOST_VRING_F_LOG is set if log address is valid + */ +struct vu_ring { + unsigned int num; + struct vring_desc *desc; + struct vring_avail *avail; + struct vring_used *used; + uint64_t log_guest_addr; + uint32_t flags; +}; + +/** + * struct vu_virtq - Virtqueue definition + * @vring: Virtqueue rings + * @last_avail_idx: Next head to pop + * @shadow_avail_idx: Last avail_idx read from VQ. + * @used_idx: Descriptor ring current index + * @signalled_used: Last used index value we have signalled on + * @signalled_used_valid: True if signalled_used if valid + * @notification: True if the queues notify (via event + * index or interrupt) + * @inuse: Number of entries in use + * @call_fd: The event file descriptor to signal when + * buffers are used. + * @kick_fd: The event file descriptor for adding + * buffers to the vring + * @err_fd: The event file descriptor to signal when + * error occurs + * @enable: True if the virtqueue is enabled + * @started: True if the virtqueue is started + * @vra: QEMU address of our rings + */ +struct vu_virtq { + struct vu_ring vring; + uint16_t last_avail_idx; + uint16_t shadow_avail_idx; + uint16_t used_idx; + uint16_t signalled_used; + bool signalled_used_valid; + bool notification; + unsigned int inuse; + int call_fd; + int kick_fd; + int err_fd; + unsigned int enable; + bool started; + struct vhost_vring_addr vra; +}; + +/** + * struct vu_dev_region - guest shared memory region + * @gpa: Guest physical address of the region + * @size: Memory size in bytes + * @qva: QEMU virtual address + * @mmap_offset: Offset where the region starts in the mapped memory + * @mmap_addr: Address of the mapped memory + */ +struct vu_dev_region { + uint64_t gpa; + uint64_t size; + uint64_t qva; + uint64_t mmap_offset; + uint64_t mmap_addr; +}; + +#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 + +/** + * struct vu_dev - vhost-user device information + * @context: Execution context + * @nregions: Number of shared memory regions + * @regions: Guest shared memory regions + * @features: Vhost-user features + * @protocol_features: Vhost-user protocol features + */ +struct vu_dev { + uint32_t nregions; + struct vu_dev_region regions[VHOST_USER_MAX_RAM_SLOTS]; + struct vu_virtq vq[VHOST_USER_MAX_QUEUES]; + uint64_t features; + uint64_t protocol_features; +}; + +/** + * struct vu_virtq_element - virtqueue element + * @index: Descriptor ring index + * @out_num: Number of outgoing iovec buffers + * @in_num: Number of incoming iovec buffers + * @in_sg: Incoming iovec buffers + * @out_sg: Outgoing iovec buffers + */ +struct vu_virtq_element { + unsigned int index; + unsigned int out_num; + unsigned int in_num; + struct iovec *in_sg; + struct iovec *out_sg; +}; + +/** + * has_feature() - Check a feature bit in a features set + * @features: Features set + * @fb: Feature bit to check + * + * Return: True if the feature bit is set + */ +static inline bool has_feature(uint64_t features, unsigned int fbit) +{ + return !!(features & (1ULL << fbit)); +} + +/** + * vu_has_feature() - Check if a virtio-net feature is available + * @vdev: Vhost-user device + * @bit: Feature to check + * + * Return: True if the feature is available + */ +static inline bool vu_has_feature(const struct vu_dev *vdev, + unsigned int fbit) +{ + return has_feature(vdev->features, fbit); +} + +/** + * vu_has_protocol_feature() - Check if a vhost-user feature is available + * @vdev: Vhost-user device + * @bit: Feature to check + * + * Return: True if the feature is available + */ +/* cppcheck-suppress unusedFunction */ +static inline bool vu_has_protocol_feature(const struct vu_dev *vdev, + unsigned int fbit) +{ + return has_feature(vdev->protocol_features, fbit); +} + +bool vu_queue_empty(struct vu_virtq *vq); +void vu_queue_notify(const struct vu_dev *dev, struct vu_virtq *vq); +int vu_queue_pop(struct vu_dev *dev, struct vu_virtq *vq, + struct vu_virtq_element *elem); +void vu_queue_detach_element(struct vu_virtq *vq); +void vu_queue_unpop(struct vu_virtq *vq); +bool vu_queue_rewind(struct vu_virtq *vq, unsigned int num); +void vu_queue_fill_by_index(struct vu_virtq *vq, unsigned int index, + unsigned int len, unsigned int idx); +void vu_queue_fill(struct vu_virtq *vq, + const struct vu_virtq_element *elem, unsigned int len, + unsigned int idx); +void vu_queue_flush(struct vu_virtq *vq, unsigned int count); +#endif /* VIRTIO_H */ |