Re: [PATCH net-next v3 00/13] virtio: support packed ring
From: "Michael S. Tsirkin" Date: Tue, 27 Nov 2018 01:08:08 -0500 > On Wed, Nov 21, 2018 at 06:03:17PM +0800, Tiwei Bie wrote: >> Hi, >> >> 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 > > I went over it and I think it's correct spec-wise. > > I have some ideas for enhancements but let's start > with getting this stuff merged first. > > Acked-by: Michael S. Tsirkin Series applied. ___ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization
Re: [PATCH net-next v3 00/13] virtio: support packed ring
On Wed, Nov 21, 2018 at 06:03:17PM +0800, Tiwei Bie wrote: > Hi, > > 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 I went over it and I think it's correct spec-wise. I have some ideas for enhancements but let's start with getting this stuff merged first. Acked-by: Michael S. Tsirkin > 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; > > > Tiwei Bie (13): > virtio: add packed ring types and macros > virtio_ring: add _split suffix for split ring functions > virtio_ring: put split ring functions together > virtio_ring: put split ring fields in a sub struct > virtio_ring: introduce debug helpers > virtio_ring: introduce helper for indirect feature > virtio_ring: allocate desc state for split ring separately > virtio_ring: extract split ring handling from ring creation > virtio_ring: cache whether we will use DMA API > virtio_ring: introduce packed ring support > virtio_ring: leverage event idx in packed ring > virtio_ring: disable packed ring on unsupported transports > virtio_ring: advertize packed ring layout > > drivers/misc/mic/vop/vop_main.c| 13 + > drivers/remoteproc/remoteproc_virtio.c | 13 + > drivers/s390/virtio/virtio_ccw.c | 14 + > drivers/virtio/virtio_ring.c | 1811 > +--- > include/uapi/linux/virtio_config.h |3 + > include/uapi/linux/virtio_ring.h | 52 + > 6 files changed, 1530 insertions(+), 376 deletions(-) > > -- > 2.14.5
Re: [PATCH net-next v3 00/13] virtio: support packed ring
From: "Michael S. Tsirkin" Date: Wed, 21 Nov 2018 07:20:27 -0500 > Dave, given the holiday, attempts to wrap up the 1.1 spec and the > patchset size I would very much appreciate a bit more time for > review. Say until Nov 28? Ok. ___ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization
Re: [PATCH net-next v3 00/13] virtio: support packed ring
On 2018/11/21 下午8:42, Tiwei Bie wrote: On Wed, Nov 21, 2018 at 07:20:27AM -0500, Michael S. Tsirkin wrote: On Wed, Nov 21, 2018 at 06:03:17PM +0800, Tiwei Bie wrote: Hi, 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. Thanks a lot, this is very exciting! Dave, given the holiday, attempts to wrap up the 1.1 spec and the patchset size I would very much appreciate a bit more time for review. Say until Nov 28? 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 Could you pls clarify - do you mean it doesn't yet work with vhost because of a vhost bug, and to test it with the linked patches you had to hack in _F_NEXT? Because I do not see _F_NEXT in indirect descriptors in this patch (which is fine). Or did I miss it? You didn't miss anything. :) I think it's a small bug in vhost, which Jason may fix very quickly, so I didn't post it. Below is the hack I used: Good catch. I didn't notice the subtle difference since split ring requires for it. Let me fix it in next version. Thanks. 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++; ___ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization
Re: [PATCH net-next v3 00/13] virtio: support packed ring
On Wed, Nov 21, 2018 at 06:03:17PM +0800, Tiwei Bie wrote: > Hi, > > 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. Thanks a lot, this is very exciting! Dave, given the holiday, attempts to wrap up the 1.1 spec and the patchset size I would very much appreciate a bit more time for review. Say until Nov 28? > 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 Could you pls clarify - do you mean it doesn't yet work with vhost because of a vhost bug, and to test it with the linked patches you had to hack in _F_NEXT? Because I do not see _F_NEXT in indirect descriptors in this patch (which is fine). Or did I miss it? > 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; > > > Tiwei Bie (13): > virtio: add packed ring types and macros > virtio_ring: add _split suffix for split ring functions > virtio_ring: put split ring functions together > virtio_ring: put split ring fields in a sub struct > virtio_ring: introduce debug helpers > virtio_ring: introduce helper for indirect feature > virtio_ring: allocate desc state for split ring separately > virtio_ring: extract split ring handling from ring creation > virtio_ring: cache whether we will use DMA API > virtio_ring: introduce packed ring support > virtio_ring: leverage event idx in packed ring > virtio_ring: disable packed ring on unsupported transports > virtio_ring: advertize packed ring layout > > drivers/misc/mic/vop/vop_main.c| 13 + > drivers/remoteproc/remoteproc_virtio.c | 13 + > drivers/s390/virtio/virtio_ccw.c | 14 + >
Re: [PATCH net-next v3 00/13] virtio: support packed ring
On Wed, Nov 21, 2018 at 07:20:27AM -0500, Michael S. Tsirkin wrote: > On Wed, Nov 21, 2018 at 06:03:17PM +0800, Tiwei Bie wrote: > > Hi, > > > > 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. > > Thanks a lot, this is very exciting! > Dave, given the holiday, attempts to wrap up the 1.1 spec and the > patchset size I would very much appreciate a bit more time for > review. Say until Nov 28? > > > 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 > > Could you pls clarify - do you mean it doesn't yet work with vhost > because of a vhost bug, and to test it with the linked patches > you had to hack in _F_NEXT? Because I do not see _F_NEXT > in indirect descriptors in this patch (which is fine). > Or did I miss it? You didn't miss anything. :) I think it's a small bug in vhost, which Jason may fix very quickly, so I didn't post it. Below is the hack I used: 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 > > > 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
[PATCH net-next v3 00/13] virtio: support packed ring
Hi, 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; Tiwei Bie (13): virtio: add packed ring types and macros virtio_ring: add _split suffix for split ring functions virtio_ring: put split ring functions together virtio_ring: put split ring fields in a sub struct virtio_ring: introduce debug helpers virtio_ring: introduce helper for indirect feature virtio_ring: allocate desc state for split ring separately virtio_ring: extract split ring handling from ring creation virtio_ring: cache whether we will use DMA API virtio_ring: introduce packed ring support virtio_ring: leverage event idx in packed ring virtio_ring: disable packed ring on unsupported transports virtio_ring: advertize packed ring layout drivers/misc/mic/vop/vop_main.c| 13 + drivers/remoteproc/remoteproc_virtio.c | 13 + drivers/s390/virtio/virtio_ccw.c | 14 + drivers/virtio/virtio_ring.c | 1811 +--- include/uapi/linux/virtio_config.h |3 + include/uapi/linux/virtio_ring.h | 52 + 6 files changed, 1530 insertions(+), 376 deletions(-) -- 2.14.5 ___ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization
