/* * Copyright (c) 2006-2021, RT-Thread Development Team * * SPDX-License-Identifier: Apache-2.0 * * Change Logs: * Date Author Notes * 2021-11-11 GuEe-GUI the first version */ #ifndef __VIRTIO_QUEUE_H__ #define __VIRTIO_QUEUE_H__ #include #define VIRTQ_DESC_F_NEXT 1 /* This marks a buffer as continuing via the next field. */ #define VIRTQ_DESC_F_WRITE 2 /* This marks a buffer as write-only (otherwise read-only). */ #define VIRTQ_DESC_F_INDIRECT 4 /* This means the buffer contains a list of buffer descriptors. */ /* * The device uses this in used->flags to advise the driver: don't kick me * when you add a buffer. It's unreliable, so it's simply an optimization. */ #define VIRTQ_USED_F_NO_NOTIFY 1 /* * The driver uses this in avail->flags to advise the device: don't * interrupt me when you consume a buffer. It's unreliable, so it's * simply an optimization. */ #define VIRTQ_AVAIL_F_NO_INTERRUPT 1 /* Virtqueue descriptors: 16 bytes. These can chain together via "next". */ struct virtq_desc { rt_uint64_t addr; /* Address (guest-physical). */ rt_uint32_t len; /* Length. */ rt_uint16_t flags; /* The flags as indicated above. */ rt_uint16_t next; /* We chain unused descriptors via this, too */ }; struct virtq_avail { rt_uint16_t flags; /* Notifications */ rt_uint16_t idx; /* Where the driver would put the next descriptor entry in the ring (modulo the queue size) */ rt_uint16_t ring[]; /* * Only if VIRTIO_F_RING_EVENT_IDX * rt_uint16_t used_event; */ }; struct virtq_used_elem { rt_uint32_t id; /* Index of start of used descriptor chain. */ rt_uint32_t len; /* Total length of the descriptor chain which was written to. */ }; struct virtq_used { rt_uint16_t flags; rt_uint16_t idx; struct virtq_used_elem ring[]; /* * Only if VIRTIO_F_RING_EVENT_IDX * rt_uint16_t avail_event; */ }; struct virtq { rt_uint32_t num; struct virtq_desc *desc; struct virtq_avail *avail; struct virtq_used *used; /* Helper of driver */ rt_uint32_t used_idx; rt_bool_t *free; rt_size_t free_count; }; #define VIRTQ_DESC_TOTAL_SIZE(ring_size) (sizeof(struct virtq_desc) * (ring_size)) /* flags, idx, used_event + ring * ring_size */ #define VIRTQ_AVAIL_TOTAL_SIZE(ring_size) (sizeof(rt_uint16_t) * 3 + sizeof(rt_uint16_t) * (ring_size)) /* flags, idx, avail_event + ring * ring_size */ #define VIRTQ_USED_TOTAL_SIZE(ring_size) (sizeof(rt_uint16_t) * 3 + sizeof(struct virtq_used_elem) * (ring_size)) #define VIRTQ_AVAIL_RES_SIZE (sizeof(rt_uint16_t)) /* used_event */ #define VIRTQ_USED_RES_SIZE (sizeof(rt_uint16_t)) /* avail_event */ #define VIRTQ_INVALID_DESC_ID RT_UINT16_MAX #endif /* __VIRTIO_QUEUE_H__ */