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Diffstat (limited to 'virtio-ring.h')
| -rw-r--r-- | virtio-ring.h | 122 |
1 files changed, 0 insertions, 122 deletions
diff --git a/virtio-ring.h b/virtio-ring.h deleted file mode 100644 index 5a1e87d..0000000 --- a/virtio-ring.h +++ /dev/null @@ -1,122 +0,0 @@ -#ifndef VIRTQUEUE_H -#define VIRTQUEUE_H -/* An interface for efficient virtio implementation. - * - * This header is BSD licensed so anyone can use the definitions - * to implement compatible drivers/servers. - * - * Copyright 2007, 2009, IBM Corporation - * Copyright 2011, Red Hat, Inc - * All rights reserved. - * - * Redistribution and use in source and binary forms, with or without - * modification, are permitted provided that the following conditions - * are met: - * 1. Redistributions of source code must retain the above copyright - * notice, this list of conditions and the following disclaimer. - * 2. Redistributions in binary form must reproduce the above copyright - * notice, this list of conditions and the following disclaimer in the - * documentation and/or other materials provided with the distribution. - * 3. Neither the name of IBM nor the names of its contributors - * may be used to endorse or promote products derived from this software - * without specific prior written permission. - * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ``AS IS'' AND - * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE - * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE - * ARE DISCLAIMED. IN NO EVENT SHALL IBM OR CONTRIBUTORS BE LIABLE - * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL - * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS - * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) - * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT - * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY - * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF - * SUCH DAMAGE. - */ -#include <stdint.h> - -/* This marks a buffer as continuing via the next field. */ -#define VIRTQ_DESC_F_NEXT 1 -/* This marks a buffer as write-only (otherwise read-only). */ -#define VIRTQ_DESC_F_WRITE 2 -/* This means the buffer contains a list of buffer descriptors. */ -#define VIRTQ_DESC_F_INDIRECT 4 - -/* 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 - -/* Support for indirect descriptors */ -#define VIRTIO_F_INDIRECT_DESC 28 - -/* Support for avail_event and used_event fields */ -#define VIRTIO_F_EVENT_IDX 29 - -/* Arbitrary descriptor layouts. */ -#define VIRTIO_F_ANY_LAYOUT 27 - -/* Virtqueue descriptors: 16 bytes. - * These can chain together via "next". */ -struct virtq_desc { - /* Address (guest-physical). */ - le64 addr; - /* Length. */ - le32 len; - /* The flags as indicated above. */ - le16 flags; - /* We chain unused descriptors via this, too */ - le16 next; -}; - -struct virtq_avail { - le16 flags; - le16 idx; - le16 ring[]; - /* Only if VIRTIO_F_EVENT_IDX: le16 used_event; */ -}; - -/* le32 is used here for ids for padding reasons. */ -struct virtq_used_elem { - /* Index of start of used descriptor chain. */ - le32 id; - /* Total length of the descriptor chain which was written to. */ - le32 len; -}; - -struct virtq_used { - le16 flags; - le16 idx; - struct virtq_used_elem ring[]; - /* Only if VIRTIO_F_EVENT_IDX: le16 avail_event; */ -}; - -struct virtq { - unsigned int num; - - struct virtq_desc *desc; - struct virtq_avail *avail; - struct virtq_used *used; -}; - -static inline int virtq_need_event(uint16_t event_idx, uint16_t new_idx, uint16_t old_idx) -{ - return (uint16_t)(new_idx - event_idx - 1) < (uint16_t)(new_idx - old_idx); -} - -/* Get location of event indices (only with VIRTIO_F_EVENT_IDX) */ -static inline le16 *virtq_used_event(struct virtq *vq) -{ - /* For backwards compat, used event index is at *end* of avail ring. */ - return &vq->avail->ring[vq->num]; -} - -static inline le16 *virtq_avail_event(struct virtq *vq) -{ - /* For backwards compat, avail event index is at *end* of used ring. */ - return (le16 *)&vq->used->ring[vq->num]; -} -#endif /* VIRTQUEUE_H */ |