Hi Wei, FYI, the latest packed ring series for guest driver doesn't set the _F_NEXT bit for indirect descriptors any more. So below hack in guest driver is needed to make it work with this series:
diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c index cd7e755484e3..42faea7d8cf8 100644 --- a/drivers/virtio/virtio_ring.c +++ b/drivers/virtio/virtio_ring.c @@ -980,6 +980,7 @@ static int virtqueue_add_indirect_packed(struct vring_virtqueue *vq, unsigned int i, n, err_idx; u16 head, id; dma_addr_t addr; + int c = 0; head = vq->packed.next_avail_idx; desc = alloc_indirect_packed(total_sg, gfp); @@ -1001,8 +1002,9 @@ static int virtqueue_add_indirect_packed(struct vring_virtqueue *vq, if (vring_mapping_error(vq, addr)) goto unmap_release; - desc[i].flags = cpu_to_le16(n < out_sgs ? - 0 : VRING_DESC_F_WRITE); + desc[i].flags = cpu_to_le16((n < out_sgs ? + 0 : VRING_DESC_F_WRITE) | + (++c == total_sg ? 0 : VRING_DESC_F_NEXT)); desc[i].addr = cpu_to_le64(addr); desc[i].len = cpu_to_le32(sg->length); i++; -- 2.14.1 On Thu, Oct 11, 2018 at 10:08:23AM -0400, w...@redhat.com wrote: > From: Wei Xu <w...@redhat.com> > > code base: > https://github.com/Whishay/qemu.git > > Todo: > - migration has not been support yet > > v2->v3 > - addressed performance issue > - fixed feedback from v2 > > v1->v2 > - sync to tiwei's v5 > - reuse memory cache function with 1.0 > - dropped detach patch and notification helper(04 & 05 in v1) > - guest virtio-net driver unload/reload support > - event suppression support(not tested) > - addressed feedback from v1 > > Wei Xu (12): > virtio: introduce packed ring definitions > virtio: redefine structure & memory cache for packed ring > virtio: init memory cache for packed ring > virtio: init wrap counter for packed ring > virtio: init and desc empty check for packed ring > virtio: get avail bytes check for packed ring > virtio: fill/flush/pop for packed ring > virtio: event suppression support for packed ring > virtio-net: fill head desc after done all in a chain > virtio: packed ring feature bit for userspace backend > virtio: enable packed ring via a new command line > virtio: feature vhost-net support for packed ring > > hw/net/vhost_net.c | 1 + > hw/net/virtio-net.c | 11 +- > hw/virtio/vhost.c | 19 +- > hw/virtio/virtio.c | 685 > +++++++++++++++++++++++-- > include/hw/virtio/virtio.h | 9 +- > include/standard-headers/linux/virtio_config.h | 15 + > include/standard-headers/linux/virtio_ring.h | 43 ++ > 7 files changed, 736 insertions(+), 47 deletions(-) > > -- > 1.8.3.1 >