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  1. 28 11月, 2018 33 次提交
  3. 27 11月, 2018 7 次提交
    • D
      Merge branch 'virtio-support-packed-ring' · 02c72d5e
      由 David S. Miller 提交于 
      Tiwei Bie says:

====================
virtio: support packed ring

This patch set implements packed ring support in virtio driver.

A performance test between pktgen (pktgen_sample03_burst_single_flow.sh)
and DPDK vhost (testpmd/rxonly/vhost-PMD) has been done, I saw
~30% performance gain in packed ring in this case.

To make this patch set work with below patch set for vhost,
some hacks are needed to set the _F_NEXT flag in indirect
descriptors (this should be fixed in vhost):

https://lkml.org/lkml/2018/7/3/33

v2 -> v3:
- Use leXX instead of virtioXX (MST);
- Refactor split ring first (MST);
- Add debug helpers (MST);
- Put split/packed ring specific fields in sub structures (MST);
- Handle normal descriptors and indirect descriptors differently (MST);
- Track the DMA addr/len related info in a separate structure (MST);
- Calculate AVAIL/USED flags only when wrap counter wraps (MST);
- Define a struct/union to read event structure (MST);
- Define a macro for wrap counter bit in uapi (MST);
- Define the AVAIL/USED bits as shifts instead of values (MST);
- s/_F_/_FLAG_/ in VRING_PACKED_EVENT_* as they are values (MST);
- Drop the notify workaround for QEMU's tx-timer in packed ring (MST);

v1 -> v2:
- Use READ_ONCE() to read event off_wrap and flags together (Jason);
- Add comments related to ccw (Jason);

RFC v6 -> v1:
- Avoid extra virtio_wmb() in virtqueue_enable_cb_delayed_packed()
  when event idx is off (Jason);
- Fix bufs calculation in virtqueue_enable_cb_delayed_packed() (Jason);
- Test the state of the desc at used_idx instead of last_used_idx
  in virtqueue_enable_cb_delayed_packed() (Jason);
- Save wrap counter (as part of queue state) in the return value
  of virtqueue_enable_cb_prepare_packed();
- Refine the packed ring definitions in uapi;
- Rebase on the net-next tree;

RFC v5 -> RFC v6:
- Avoid tracking addr/len/flags when DMA API isn't used (MST/Jason);
- Define wrap counter as bool (Jason);
- Use ALIGN() in vring_init_packed() (Jason);
- Avoid using pointer to track `next` in detach_buf_packed() (Jason);
- Add comments for barriers (Jason);
- Don't enable RING_PACKED on ccw for now (noticed by Jason);
- Refine the memory barrier in virtqueue_poll();
- Add a missing memory barrier in virtqueue_enable_cb_delayed_packed();
- Remove the hacks in virtqueue_enable_cb_prepare_packed();

RFC v4 -> RFC v5:
- Save DMA addr, etc in desc state (Jason);
- Track used wrap counter;

RFC v3 -> RFC v4:
- Make ID allocation support out-of-order (Jason);
- Various fixes for EVENT_IDX support;

RFC v2 -> RFC v3:
- Split into small patches (Jason);
- Add helper virtqueue_use_indirect() (Jason);
- Just set id for the last descriptor of a list (Jason);
- Calculate the prev in virtqueue_add_packed() (Jason);
- Fix/improve desc suppression code (Jason/MST);
- Refine the code layout for XXX_split/packed and wrappers (MST);
- Fix the comments and API in uapi (MST);
- Remove the BUG_ON() for indirect (Jason);
- Some other refinements and bug fixes;

RFC v1 -> RFC v2:
- Add indirect descriptor support - compile test only;
- Add event suppression supprt - compile test only;
- Move vring_packed_init() out of uapi (Jason, MST);
- Merge two loops into one in virtqueue_add_packed() (Jason);
- Split vring_unmap_one() for packed ring and split ring (Jason);
- Avoid using '%' operator (Jason);
- Rename free_head -> next_avail_idx (Jason);
- Add comments for virtio_wmb() in virtqueue_add_packed() (Jason);
- Some other refinements and bug fixes;
====================
Acked-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      02c72d5e
    • T
      virtio_ring: advertize packed ring layout · f959a128
      由 Tiwei Bie 提交于 
      Advertize the packed ring layout support.
Signed-off-by: NTiwei Bie <tiwei.bie@intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      f959a128
    • T
      virtio_ring: disable packed ring on unsupported transports · 3a814fdf
      由 Tiwei Bie 提交于 
      Currently, ccw, vop and remoteproc need some legacy virtio
APIs to create or access virtio rings, which are not supported
by packed ring. So disable packed ring on these transports
for now.
Signed-off-by: NTiwei Bie <tiwei.bie@intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      3a814fdf
    • T
      virtio_ring: leverage event idx in packed ring · f51f9826
      由 Tiwei Bie 提交于 
      Leverage the EVENT_IDX feature in packed ring to suppress
events when it's available.
Signed-off-by: NTiwei Bie <tiwei.bie@intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      f51f9826
    • T
      virtio_ring: introduce packed ring support · 1ce9e605
      由 Tiwei Bie 提交于 
      Introduce the packed ring support. Packed ring can only be
created by vring_create_virtqueue() and each chunk of packed
ring will be allocated individually. Packed ring can not be
created on preallocated memory by vring_new_virtqueue() or
the likes currently.
Signed-off-by: NTiwei Bie <tiwei.bie@intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      1ce9e605
    • T
      virtio_ring: cache whether we will use DMA API · fb3fba6b
      由 Tiwei Bie 提交于 
      Cache whether we will use DMA API, instead of doing the
check every time. We are going to check whether DMA API
is used more often in packed ring.
Signed-off-by: NTiwei Bie <tiwei.bie@intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      fb3fba6b
    • T
      virtio_ring: extract split ring handling from ring creation · d79dca75
      由 Tiwei Bie 提交于 
      Introduce a specific function to create the split ring.
And also move the DMA allocation and size information to
the .split sub-structure.
Signed-off-by: NTiwei Bie <tiwei.bie@intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      d79dca75