On Wed, Jan 16, 2019 at 01:31:06PM -0500, w...@redhat.com wrote:
> From: Wei Xu
>
> >From 1.1 spec.
>
> Signed-off-by: Wei Xu
So pls don't open-code this in qemu. These headers should come
from Linux using scripts/update-linux-headers.sh.
> ---
> include/standard-headers/linux/virtio_config.h | 15 +
> include/standard-headers/linux/virtio_ring.h | 43
> ++
> 2 files changed, 58 insertions(+)
>
> diff --git a/include/standard-headers/linux/virtio_config.h
> b/include/standard-headers/linux/virtio_config.h
> index 0b19436..9f450fd 100644
> --- a/include/standard-headers/linux/virtio_config.h
> +++ b/include/standard-headers/linux/virtio_config.h
> @@ -75,6 +75,21 @@
> */
> #define VIRTIO_F_IOMMU_PLATFORM 33
>
> +/* This feature indicates support for the packed virtqueue layout. */
> +#define VIRTIO_F_RING_PACKED 34
> +
> +/* Enable events */
> +#define RING_EVENT_FLAGS_ENABLE 0x0
> +/* Disable events */
> +#define RING_EVENT_FLAGS_DISABLE 0x1
> +/*
> + * * Enable events for a specific descriptor
> + * * (as specified by Descriptor Ring Change Event Offset/Wrap Counter).
> + ** Only valid if VIRTIO_F_RING_EVENT_IDX has been negotiated.
> + * */
Above is formatted very strangely. Prefix RING_ is also probably
not a good one. Linux uses VRING.
> +#define RING_EVENT_FLAGS_DESC 0x2
> +/* The value 0x3 is reserved */
> +
> /*
> * Does the device support Single Root I/O Virtualization?
> */
> diff --git a/include/standard-headers/linux/virtio_ring.h
> b/include/standard-headers/linux/virtio_ring.h
> index d26e72b..1719c6f 100644
> --- a/include/standard-headers/linux/virtio_ring.h
> +++ b/include/standard-headers/linux/virtio_ring.h
> @@ -42,6 +42,10 @@
> /* This means the buffer contains a list of buffer descriptors. */
> #define VRING_DESC_F_INDIRECT4
>
> +/* Mark a descriptor as available or used. */
> +#define VRING_DESC_F_AVAIL (1ul << 7)
> +#define VRING_DESC_F_USED(1ul << 15)
> +
> /* The Host uses this in used->flags to advise the Guest: don't kick me when
> * you add a buffer. It's unreliable, so it's simply an optimization. Guest
> * will still kick if it's out of buffers. */
> @@ -51,6 +55,17 @@
> * optimization. */
> #define VRING_AVAIL_F_NO_INTERRUPT 1
>
> +/* Enable events. */
> +#define VRING_EVENT_F_ENABLE 0x0
> +/* Disable events. */
> +#define VRING_EVENT_F_DISABLE0x1
> +/*
> + * Enable events for a specific descriptor
> + * (as specified by Descriptor Ring Change Event Offset/Wrap Counter).
> + * Only valid if VIRTIO_RING_F_EVENT_IDX has been negotiated.
> + */
> +#define VRING_EVENT_F_DESC 0x2
> +
> /* We support indirect buffer descriptors */
> #define VIRTIO_RING_F_INDIRECT_DESC 28
>
> @@ -169,4 +184,32 @@ static inline int vring_need_event(uint16_t event_idx,
> uint16_t new_idx, uint16_
> return (uint16_t)(new_idx - event_idx - 1) < (uint16_t)(new_idx - old);
> }
>
> +struct vring_packed_desc_event {
> + /* Descriptor Ring Change Event Offset/Wrap Counter. */
> + __virtio16 off_wrap;
> + /* Descriptor Ring Change Event Flags. */
> + __virtio16 flags;
> +};
> +
> +struct vring_packed_desc {
> + /* Buffer Address. */
> + __virtio64 addr;
> + /* Buffer Length. */
> + __virtio32 len;
> + /* Buffer ID. */
> + __virtio16 id;
> + /* The flags depending on descriptor type. */
> + __virtio16 flags;
> +};
This seems strange. I don't think this needs __virtio variants -
they are unconditionally LE.
> +
> +struct vring_packed {
> + unsigned int num;
> +
> + struct vring_packed_desc *desc;
> +
> + struct vring_packed_desc_event *driver;
> +
> + struct vring_packed_desc_event *device;
> +};
> +
I don't know why we have this in the UAPI. I think it's a good idea
to drop it, in Linux as well.
> #endif /* _LINUX_VIRTIO_RING_H */
> --
> 1.8.3.1
