On Fri, Nov 30, 2018 at 04:10:55PM +0800, Jason Wang wrote: > > On 2018/11/21 下午6:03, Tiwei Bie wrote: > > Add types and macros for packed ring. > > > > Signed-off-by: Tiwei Bie <tiwei....@intel.com> > > --- > > include/uapi/linux/virtio_config.h | 3 +++ > > include/uapi/linux/virtio_ring.h | 52 > > ++++++++++++++++++++++++++++++++++++++ > > 2 files changed, 55 insertions(+) > > > > diff --git a/include/uapi/linux/virtio_config.h > > b/include/uapi/linux/virtio_config.h > > index 449132c76b1c..1196e1c1d4f6 100644 > > --- a/include/uapi/linux/virtio_config.h > > +++ b/include/uapi/linux/virtio_config.h > > @@ -75,6 +75,9 @@ > > */ > > #define VIRTIO_F_IOMMU_PLATFORM 33 > > +/* This feature indicates support for the packed virtqueue layout. */ > > +#define VIRTIO_F_RING_PACKED 34 > > + > > /* > > * Does the device support Single Root I/O Virtualization? > > */ > > diff --git a/include/uapi/linux/virtio_ring.h > > b/include/uapi/linux/virtio_ring.h > > index 6d5d5faa989b..2414f8af26b3 100644 > > --- a/include/uapi/linux/virtio_ring.h > > +++ b/include/uapi/linux/virtio_ring.h > > @@ -44,6 +44,13 @@ > > /* This means the buffer contains a list of buffer descriptors. */ > > #define VRING_DESC_F_INDIRECT 4 > > +/* > > + * Mark a descriptor as available or used in packed ring. > > + * Notice: they are defined as shifts instead of shifted values. > > > This looks inconsistent to previous flags, any reason for using shifts?
Yeah, it was suggested to use shifts, as _F_ should be a bit number, not a shifted value: https://patchwork.ozlabs.org/patch/942296/#1989390 > > > > + */ > > +#define VRING_PACKED_DESC_F_AVAIL 7 > > +#define VRING_PACKED_DESC_F_USED 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. */ > > @@ -53,6 +60,23 @@ > > * optimization. */ > > #define VRING_AVAIL_F_NO_INTERRUPT 1 > > +/* Enable events in packed ring. */ > > +#define VRING_PACKED_EVENT_FLAG_ENABLE 0x0 > > +/* Disable events in packed ring. */ > > +#define VRING_PACKED_EVENT_FLAG_DISABLE 0x1 > > +/* > > + * Enable events for a specific descriptor in packed ring. > > + * (as specified by Descriptor Ring Change Event Offset/Wrap Counter). > > + * Only valid if VIRTIO_RING_F_EVENT_IDX has been negotiated. > > + */ > > +#define VRING_PACKED_EVENT_FLAG_DESC 0x2 > > > Any reason for using _FLAG_ instead of _F_? Yeah, it was suggested to not use _F_, as these are values, should not have _F_: https://patchwork.ozlabs.org/patch/942296/#1989390 Regards, Tiwei > > Thanks > > > > + > > +/* > > + * Wrap counter bit shift in event suppression structure > > + * of packed ring. > > + */ > > +#define VRING_PACKED_EVENT_F_WRAP_CTR 15 > > + > > /* We support indirect buffer descriptors */ > > #define VIRTIO_RING_F_INDIRECT_DESC 28 > > @@ -171,4 +195,32 @@ static inline int vring_need_event(__u16 event_idx, > > __u16 new_idx, __u16 old) > > return (__u16)(new_idx - event_idx - 1) < (__u16)(new_idx - old); > > } > > +struct vring_packed_desc_event { > > + /* Descriptor Ring Change Event Offset/Wrap Counter. */ > > + __le16 off_wrap; > > + /* Descriptor Ring Change Event Flags. */ > > + __le16 flags; > > +}; > > + > > +struct vring_packed_desc { > > + /* Buffer Address. */ > > + __le64 addr; > > + /* Buffer Length. */ > > + __le32 len; > > + /* Buffer ID. */ > > + __le16 id; > > + /* The flags depending on descriptor type. */ > > + __le16 flags; > > +}; > > + > > +struct vring_packed { > > + unsigned int num; > > + > > + struct vring_packed_desc *desc; > > + > > + struct vring_packed_desc_event *driver; > > + > > + struct vring_packed_desc_event *device; > > +}; > > + > > #endif /* _UAPI_LINUX_VIRTIO_RING_H */ _______________________________________________ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization
