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author | Michael S. Tsirkin <mst@redhat.com> | 2014-10-22 15:35:56 +0300 |
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committer | Michael S. Tsirkin <mst@redhat.com> | 2014-12-09 12:05:24 +0200 |
commit | eef960a04354d13426c43a4e3750a5e2b383040c (patch) | |
tree | a5d6e327dbb22c85b2f6592077a544bcc0153471 /include/uapi/linux/virtio_ring.h | |
parent | 4ec22faeb2a165b6ce7009f91309046010b3f282 (diff) | |
download | op-kernel-dev-eef960a04354d13426c43a4e3750a5e2b383040c.zip op-kernel-dev-eef960a04354d13426c43a4e3750a5e2b383040c.tar.gz |
virtio: memory access APIs
virtio 1.0 makes all memory structures LE, so
we need APIs to conditionally do a byteswap on BE
architectures.
To make it easier to check code statically,
add virtio specific types for multi-byte integers
in memory.
Add low level wrappers that do a byteswap conditionally, these will be
useful e.g. for vhost. Add high level wrappers that
query device endian-ness and act accordingly.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Diffstat (limited to 'include/uapi/linux/virtio_ring.h')
-rw-r--r-- | include/uapi/linux/virtio_ring.h | 45 |
1 files changed, 23 insertions, 22 deletions
diff --git a/include/uapi/linux/virtio_ring.h b/include/uapi/linux/virtio_ring.h index a99f9b7..61c818a 100644 --- a/include/uapi/linux/virtio_ring.h +++ b/include/uapi/linux/virtio_ring.h @@ -32,6 +32,7 @@ * * Copyright Rusty Russell IBM Corporation 2007. */ #include <linux/types.h> +#include <linux/virtio_types.h> /* This marks a buffer as continuing via the next field. */ #define VRING_DESC_F_NEXT 1 @@ -61,32 +62,32 @@ /* Virtio ring descriptors: 16 bytes. These can chain together via "next". */ struct vring_desc { /* Address (guest-physical). */ - __u64 addr; + __virtio64 addr; /* Length. */ - __u32 len; + __virtio32 len; /* The flags as indicated above. */ - __u16 flags; + __virtio16 flags; /* We chain unused descriptors via this, too */ - __u16 next; + __virtio16 next; }; struct vring_avail { - __u16 flags; - __u16 idx; - __u16 ring[]; + __virtio16 flags; + __virtio16 idx; + __virtio16 ring[]; }; /* u32 is used here for ids for padding reasons. */ struct vring_used_elem { /* Index of start of used descriptor chain. */ - __u32 id; + __virtio32 id; /* Total length of the descriptor chain which was used (written to) */ - __u32 len; + __virtio32 len; }; struct vring_used { - __u16 flags; - __u16 idx; + __virtio16 flags; + __virtio16 idx; struct vring_used_elem ring[]; }; @@ -109,25 +110,25 @@ struct vring { * struct vring_desc desc[num]; * * // A ring of available descriptor heads with free-running index. - * __u16 avail_flags; - * __u16 avail_idx; - * __u16 available[num]; - * __u16 used_event_idx; + * __virtio16 avail_flags; + * __virtio16 avail_idx; + * __virtio16 available[num]; + * __virtio16 used_event_idx; * * // Padding to the next align boundary. * char pad[]; * * // A ring of used descriptor heads with free-running index. - * __u16 used_flags; - * __u16 used_idx; + * __virtio16 used_flags; + * __virtio16 used_idx; * struct vring_used_elem used[num]; - * __u16 avail_event_idx; + * __virtio16 avail_event_idx; * }; */ /* We publish the used event index at the end of the available ring, and vice * versa. They are at the end for backwards compatibility. */ #define vring_used_event(vr) ((vr)->avail->ring[(vr)->num]) -#define vring_avail_event(vr) (*(__u16 *)&(vr)->used->ring[(vr)->num]) +#define vring_avail_event(vr) (*(__virtio16 *)&(vr)->used->ring[(vr)->num]) static inline void vring_init(struct vring *vr, unsigned int num, void *p, unsigned long align) @@ -135,15 +136,15 @@ static inline void vring_init(struct vring *vr, unsigned int num, void *p, vr->num = num; vr->desc = p; vr->avail = p + num*sizeof(struct vring_desc); - vr->used = (void *)(((unsigned long)&vr->avail->ring[num] + sizeof(__u16) + vr->used = (void *)(((unsigned long)&vr->avail->ring[num] + sizeof(__virtio16) + align-1) & ~(align - 1)); } static inline unsigned vring_size(unsigned int num, unsigned long align) { - return ((sizeof(struct vring_desc) * num + sizeof(__u16) * (3 + num) + return ((sizeof(struct vring_desc) * num + sizeof(__virtio16) * (3 + num) + align - 1) & ~(align - 1)) - + sizeof(__u16) * 3 + sizeof(struct vring_used_elem) * num; + + sizeof(__virtio16) * 3 + sizeof(struct vring_used_elem) * num; } /* The following is used with USED_EVENT_IDX and AVAIL_EVENT_IDX */ |