[dpdk-dev] [PATCH 0/2] Vhost & Virtio fixes for -rc4

[dpdk-dev] [PATCH 0/2] Vhost & Virtio fixes for -rc4

[Maxime Coquelin]

This two patches series fixes two regressions met with virtio-user.
The first one is only reproduced when using the Vector path,
the second one may be met whatever the rx function.

Maxime Coquelin (2):
  virtio: fix resuming traffic with rx vector path
  vhost: don't take access_lock on VHOST_USER_RESET_OWNER

 drivers/net/virtio/virtio_rxtx.c        | 34 ++++++++++++++++++---------------
 drivers/net/virtio/virtio_rxtx_simple.c |  2 +-
 drivers/net/virtio/virtio_rxtx_simple.h |  2 +-
 lib/librte_vhost/vhost_user.c           | 10 +++++-----
 4 files changed, 26 insertions(+), 22 deletions(-)

-- 
2.14.3

[dpdk-dev] [PATCH 1/2] virtio: fix resuming traffic with rx vector path

[Maxime Coquelin]

This patch fixes traffic resuming issue seen when using
Rx vector path.

Fixes: efc83a1e7fc3 ("net/virtio: fix queue setup consistency")

Signed-off-by: Tiwei Bie <tiwei.bie@intel.com>
Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
---
 drivers/net/virtio/virtio_rxtx.c        | 34 ++++++++++++++++++---------------
 drivers/net/virtio/virtio_rxtx_simple.c |  2 +-
 drivers/net/virtio/virtio_rxtx_simple.h |  2 +-
 3 files changed, 21 insertions(+), 17 deletions(-)

diff --git a/drivers/net/virtio/virtio_rxtx.c b/drivers/net/virtio/virtio_rxtx.c
index 854af399e..505283edd 100644
--- a/drivers/net/virtio/virtio_rxtx.c
+++ b/drivers/net/virtio/virtio_rxtx.c
@@ -30,6 +30,7 @@
 #include "virtio_pci.h"
 #include "virtqueue.h"
 #include "virtio_rxtx.h"
+#include "virtio_rxtx_simple.h"
 
 #ifdef RTE_LIBRTE_VIRTIO_DEBUG_DUMP
 #define VIRTIO_DUMP_PACKET(m, len) rte_pktmbuf_dump(stdout, m, len)
@@ -446,25 +447,28 @@ virtio_dev_rx_queue_setup_finish(struct rte_eth_dev *dev, uint16_t queue_idx)
 			&rxvq->fake_mbuf;
 	}
 
-	while (!virtqueue_full(vq)) {
-		m = rte_mbuf_raw_alloc(rxvq->mpool);
-		if (m == NULL)
-			break;
+	if (hw->use_simple_rx) {
+		while (vq->vq_free_cnt >= RTE_VIRTIO_VPMD_RX_REARM_THRESH) {
+			virtio_rxq_rearm_vec(rxvq);
+			nbufs += RTE_VIRTIO_VPMD_RX_REARM_THRESH;
+		}
+	} else {
+		while (!virtqueue_full(vq)) {
+			m = rte_mbuf_raw_alloc(rxvq->mpool);
+			if (m == NULL)
+				break;
 
-		/* Enqueue allocated buffers */
-		if (hw->use_simple_rx)
-			error = virtqueue_enqueue_recv_refill_simple(vq, m);
-		else
+			/* Enqueue allocated buffers */
 			error = virtqueue_enqueue_recv_refill(vq, m);
-
-		if (error) {
-			rte_pktmbuf_free(m);
-			break;
+			if (error) {
+				rte_pktmbuf_free(m);
+				break;
+			}
+			nbufs++;
 		}
-		nbufs++;
-	}
 
-	vq_update_avail_idx(vq);
+		vq_update_avail_idx(vq);
+	}
 
 	PMD_INIT_LOG(DEBUG, "Allocated %d bufs", nbufs);
 
diff --git a/drivers/net/virtio/virtio_rxtx_simple.c b/drivers/net/virtio/virtio_rxtx_simple.c
index 7247a0822..0a79d1d5b 100644
--- a/drivers/net/virtio/virtio_rxtx_simple.c
+++ b/drivers/net/virtio/virtio_rxtx_simple.c
@@ -77,7 +77,7 @@ virtio_xmit_pkts_simple(void *tx_queue, struct rte_mbuf **tx_pkts,
 	rte_compiler_barrier();
 
 	if (nb_used >= VIRTIO_TX_FREE_THRESH)
-		virtio_xmit_cleanup(vq);
+		virtio_xmit_cleanup_simple(vq);
 
 	nb_commit = nb_pkts = RTE_MIN((vq->vq_free_cnt >> 1), nb_pkts);
 	desc_idx = (uint16_t)(vq->vq_avail_idx & desc_idx_max);
diff --git a/drivers/net/virtio/virtio_rxtx_simple.h b/drivers/net/virtio/virtio_rxtx_simple.h
index 2d8e6b14a..303904d64 100644
--- a/drivers/net/virtio/virtio_rxtx_simple.h
+++ b/drivers/net/virtio/virtio_rxtx_simple.h
@@ -60,7 +60,7 @@ virtio_rxq_rearm_vec(struct virtnet_rx *rxvq)
 #define VIRTIO_TX_FREE_NR 32
 /* TODO: vq->tx_free_cnt could mean num of free slots so we could avoid shift */
 static inline void
-virtio_xmit_cleanup(struct virtqueue *vq)
+virtio_xmit_cleanup_simple(struct virtqueue *vq)
 {
 	uint16_t i, desc_idx;
 	uint32_t nb_free = 0;
-- 
2.14.3

Re: [dpdk-dev] [PATCH 1/2] virtio: fix resuming traffic with rx vector path

[Yao, Lei A]

> -----Original Message-----
> From: Maxime Coquelin [mailto:maxime.coquelin@redhat.com]
> Sent: Friday, February 9, 2018 10:27 PM
> To: Bie, Tiwei <tiwei.bie@intel.com>; yliu@fridaylinux.org; Yigit, Ferruh
> <ferruh.yigit@intel.com>; victork@redhat.com
> Cc: dev@dpdk.org; stable@dpdk.org; Wang, Zhihong
> <zhihong.wang@intel.com>; Xu, Qian Q <qian.q.xu@intel.com>; Yao, Lei A
> <lei.a.yao@intel.com>; Maxime Coquelin <maxime.coquelin@redhat.com>
> Subject: [PATCH 1/2] virtio: fix resuming traffic with rx vector path
> 
> This patch fixes traffic resuming issue seen when using
> Rx vector path.
> 
> Fixes: efc83a1e7fc3 ("net/virtio: fix queue setup consistency")
> 
> Signed-off-by: Tiwei Bie <tiwei.bie@intel.com>
> Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Tested-by: Lei Yao <lei.a.yao@intel.com>
This patch has been tested by regression test suite. It can fix the traffic resume 
issue with vector path.  No performance drop during PVP test:

Following test are also checked and passed:
Vhost/virtio multi queue
Virtio-user
Virtio-user as exception path
Vhost/virtio reconnect

My server info:
OS: Ubuntu 16.04
Kernel: 4.4.0-110
CPU: Intel(R) Xeon(R) CPU E5-2699 v4 @ 2.20GHz

BR
Lei

> ---
>  drivers/net/virtio/virtio_rxtx.c        | 34 ++++++++++++++++++---------------
>  drivers/net/virtio/virtio_rxtx_simple.c |  2 +-
>  drivers/net/virtio/virtio_rxtx_simple.h |  2 +-
>  3 files changed, 21 insertions(+), 17 deletions(-)
> 
> diff --git a/drivers/net/virtio/virtio_rxtx.c b/drivers/net/virtio/virtio_rxtx.c
> index 854af399e..505283edd 100644
> --- a/drivers/net/virtio/virtio_rxtx.c
> +++ b/drivers/net/virtio/virtio_rxtx.c
> @@ -30,6 +30,7 @@
>  #include "virtio_pci.h"
>  #include "virtqueue.h"
>  #include "virtio_rxtx.h"
> +#include "virtio_rxtx_simple.h"
> 
>  #ifdef RTE_LIBRTE_VIRTIO_DEBUG_DUMP
>  #define VIRTIO_DUMP_PACKET(m, len) rte_pktmbuf_dump(stdout, m, len)
> @@ -446,25 +447,28 @@ virtio_dev_rx_queue_setup_finish(struct
> rte_eth_dev *dev, uint16_t queue_idx)
>  			&rxvq->fake_mbuf;
>  	}
> 
> -	while (!virtqueue_full(vq)) {
> -		m = rte_mbuf_raw_alloc(rxvq->mpool);
> -		if (m == NULL)
> -			break;
> +	if (hw->use_simple_rx) {
> +		while (vq->vq_free_cnt >=
> RTE_VIRTIO_VPMD_RX_REARM_THRESH) {
> +			virtio_rxq_rearm_vec(rxvq);
> +			nbufs += RTE_VIRTIO_VPMD_RX_REARM_THRESH;
> +		}
> +	} else {
> +		while (!virtqueue_full(vq)) {
> +			m = rte_mbuf_raw_alloc(rxvq->mpool);
> +			if (m == NULL)
> +				break;
> 
> -		/* Enqueue allocated buffers */
> -		if (hw->use_simple_rx)
> -			error = virtqueue_enqueue_recv_refill_simple(vq,
> m);
> -		else
> +			/* Enqueue allocated buffers */
>  			error = virtqueue_enqueue_recv_refill(vq, m);
> -
> -		if (error) {
> -			rte_pktmbuf_free(m);
> -			break;
> +			if (error) {
> +				rte_pktmbuf_free(m);
> +				break;
> +			}
> +			nbufs++;
>  		}
> -		nbufs++;
> -	}
> 
> -	vq_update_avail_idx(vq);
> +		vq_update_avail_idx(vq);
> +	}
> 
>  	PMD_INIT_LOG(DEBUG, "Allocated %d bufs", nbufs);
> 
> diff --git a/drivers/net/virtio/virtio_rxtx_simple.c
> b/drivers/net/virtio/virtio_rxtx_simple.c
> index 7247a0822..0a79d1d5b 100644
> --- a/drivers/net/virtio/virtio_rxtx_simple.c
> +++ b/drivers/net/virtio/virtio_rxtx_simple.c
> @@ -77,7 +77,7 @@ virtio_xmit_pkts_simple(void *tx_queue, struct
> rte_mbuf **tx_pkts,
>  	rte_compiler_barrier();
> 
>  	if (nb_used >= VIRTIO_TX_FREE_THRESH)
> -		virtio_xmit_cleanup(vq);
> +		virtio_xmit_cleanup_simple(vq);
> 
>  	nb_commit = nb_pkts = RTE_MIN((vq->vq_free_cnt >> 1), nb_pkts);
>  	desc_idx = (uint16_t)(vq->vq_avail_idx & desc_idx_max);
> diff --git a/drivers/net/virtio/virtio_rxtx_simple.h
> b/drivers/net/virtio/virtio_rxtx_simple.h
> index 2d8e6b14a..303904d64 100644
> --- a/drivers/net/virtio/virtio_rxtx_simple.h
> +++ b/drivers/net/virtio/virtio_rxtx_simple.h
> @@ -60,7 +60,7 @@ virtio_rxq_rearm_vec(struct virtnet_rx *rxvq)
>  #define VIRTIO_TX_FREE_NR 32
>  /* TODO: vq->tx_free_cnt could mean num of free slots so we could avoid
> shift */
>  static inline void
> -virtio_xmit_cleanup(struct virtqueue *vq)
> +virtio_xmit_cleanup_simple(struct virtqueue *vq)
>  {
>  	uint16_t i, desc_idx;
>  	uint32_t nb_free = 0;
> --
> 2.14.3

Re: [dpdk-dev] [PATCH 1/2] virtio: fix resuming traffic with rx vector path

[Olivier Matz]

On Fri, Feb 09, 2018 at 03:26:53PM +0100, Maxime Coquelin wrote:
> This patch fixes traffic resuming issue seen when using
> Rx vector path.
> 
> Fixes: efc83a1e7fc3 ("net/virtio: fix queue setup consistency")
> 
> Signed-off-by: Tiwei Bie <tiwei.bie@intel.com>
> Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>

Proposed change for a more detailed commit log (thanks Tiwei for
the explanation):

Since commit efc83a1e7fc3 ("net/virtio: fix queue setup consistency"),
when resuming a virtio port, the rx rings are refilled with new mbufs
until they are full (vq->vq_free_cnt == 0). This is done without
ensuring that the descriptor index remains a multiple of
RTE_VIRTIO_VPMD_RX_REARM_THRESH, which is a prerequisite when using the
vector mode. This can cause an out of bound access in the rx ring.

This commit changes the vector refill method from
virtqueue_enqueue_recv_refill_simple() to virtio_rxq_rearm_vec(), which
properly checks that the refill is done by batch of
RTE_VIRTIO_VPMD_RX_REARM_THRESH.

> ---
>  drivers/net/virtio/virtio_rxtx.c        | 34 ++++++++++++++++++---------------
>  drivers/net/virtio/virtio_rxtx_simple.c |  2 +-
>  drivers/net/virtio/virtio_rxtx_simple.h |  2 +-
>  3 files changed, 21 insertions(+), 17 deletions(-)
> 
> diff --git a/drivers/net/virtio/virtio_rxtx.c b/drivers/net/virtio/virtio_rxtx.c
> index 854af399e..505283edd 100644
> --- a/drivers/net/virtio/virtio_rxtx.c
> +++ b/drivers/net/virtio/virtio_rxtx.c
> @@ -30,6 +30,7 @@
>  #include "virtio_pci.h"
>  #include "virtqueue.h"
>  #include "virtio_rxtx.h"
> +#include "virtio_rxtx_simple.h"
>  
>  #ifdef RTE_LIBRTE_VIRTIO_DEBUG_DUMP
>  #define VIRTIO_DUMP_PACKET(m, len) rte_pktmbuf_dump(stdout, m, len)
> @@ -446,25 +447,28 @@ virtio_dev_rx_queue_setup_finish(struct rte_eth_dev *dev, uint16_t queue_idx)
>  			&rxvq->fake_mbuf;
>  	}
>  
> -	while (!virtqueue_full(vq)) {
> -		m = rte_mbuf_raw_alloc(rxvq->mpool);
> -		if (m == NULL)
> -			break;
> +	if (hw->use_simple_rx) {
> +		while (vq->vq_free_cnt >= RTE_VIRTIO_VPMD_RX_REARM_THRESH) {
> +			virtio_rxq_rearm_vec(rxvq);
> +			nbufs += RTE_VIRTIO_VPMD_RX_REARM_THRESH;
> +		}
> +	} else {
> +		while (!virtqueue_full(vq)) {
> +			m = rte_mbuf_raw_alloc(rxvq->mpool);
> +			if (m == NULL)
> +				break;
>  
> -		/* Enqueue allocated buffers */
> -		if (hw->use_simple_rx)
> -			error = virtqueue_enqueue_recv_refill_simple(vq, m);
> -		else

It looks that virtqueue_enqueue_recv_refill_simple() is not used anymore.
We may want to remove it.

It means this patch also fixes the issue related to the patch I've just
submitted [1]. To ease backport process, I think the patch [1] is still
relevant because it fixes an older commit.

[1] http://dpdk.org/dev/patchwork/patch/35130/


> +			/* Enqueue allocated buffers */
>  			error = virtqueue_enqueue_recv_refill(vq, m);
> -
> -		if (error) {
> -			rte_pktmbuf_free(m);
> -			break;
> +			if (error) {
> +				rte_pktmbuf_free(m);
> +				break;
> +			}
> +			nbufs++;
>  		}
> -		nbufs++;
> -	}
>  
> -	vq_update_avail_idx(vq);
> +		vq_update_avail_idx(vq);
> +	}
>  
>  	PMD_INIT_LOG(DEBUG, "Allocated %d bufs", nbufs);
>  
>  	virtio_rxq_vec_setup(rxvq);

Another thing seen by Tiwei: virtio_rxq_vec_setup() should be called
before virtio_rxq_rearm_vec() because it initializes the mbuf
initializer.

Thanks,
Olivier

Re: [dpdk-dev] [PATCH 1/2] virtio: fix resuming traffic with rx vector path

[Tan, Jianfeng]

Just realize that I forgot to CC dev@dpdk.org.

> -----Original Message-----
> From: Tan, Jianfeng [mailto:jianfeng.tan@intel.com]
> Sent: Monday, February 12, 2018 8:51 PM
> To: Maxime Coquelin
> Subject: Re: [dpdk-dev] [PATCH 1/2] virtio: fix resuming traffic with rx vector
> path
> 
> 
> 
> On 2/9/2018 10:26 PM, Maxime Coquelin wrote:
> > This patch fixes traffic resuming issue seen when using
> > Rx vector path.
> 
> A nit: AFAIK, this issue happens after start/stop/start? "traffic
> resuming" seems not accurate.
> 
> >
> > Fixes: efc83a1e7fc3 ("net/virtio: fix queue setup consistency")
> >
> > Signed-off-by: Tiwei Bie <tiwei.bie@intel.com>
> > Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
> 
> Besides that,
> 
> Reviewed-by: Jianfeng Tan <jianfeng.tan@intel.com>
> 
> Thanks for this timely fix!
> 
> Thanks,
> Jianfeng

[dpdk-dev] [PATCH 2/2] vhost: don't take access_lock on VHOST_USER_RESET_OWNER

[Maxime Coquelin]

A deadlock happens when handling VHOST_USER_RESET_OWNER request
for the same reason the lock is not taken for
VHOST_USER_GET_VRING_BASE.

It is safe not to take the lock, as the queues are no more used
by the application when the virtqueues and the device are reset.

Fixes: a3688046995f ("vhost: protect active rings from async ring changes")
Cc: stable@dpdk.org

Cc: Victor Kaplansky <victork@redhat.com>
Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
---
 lib/librte_vhost/vhost_user.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c
index 65ee33919..90ed2112e 100644
--- a/lib/librte_vhost/vhost_user.c
+++ b/lib/librte_vhost/vhost_user.c
@@ -1348,16 +1348,16 @@ vhost_user_msg_handler(int vid, int fd)
 	}
 
 	/*
-	 * Note: we don't lock all queues on VHOST_USER_GET_VRING_BASE,
-	 * since it is sent when virtio stops and device is destroyed.
-	 * destroy_device waits for queues to be inactive, so it is safe.
-	 * Otherwise taking the access_lock would cause a dead lock.
+	 * Note: we don't lock all queues on VHOST_USER_GET_VRING_BASE
+	 * and VHOST_USER_RESET_OWNER, since it is sent when virtio stops
+	 * and device is destroyed. destroy_device waits for queues to be
+	 * inactive, so it is safe. Otherwise taking the access_lock
+	 * would cause a dead lock.
 	 */
 	switch (msg.request.master) {
 	case VHOST_USER_SET_FEATURES:
 	case VHOST_USER_SET_PROTOCOL_FEATURES:
 	case VHOST_USER_SET_OWNER:
-	case VHOST_USER_RESET_OWNER:
 	case VHOST_USER_SET_MEM_TABLE:
 	case VHOST_USER_SET_LOG_BASE:
 	case VHOST_USER_SET_LOG_FD:
-- 
2.14.3

Re: [dpdk-dev] [PATCH 2/2] vhost: don't take access_lock on VHOST_USER_RESET_OWNER

[Tiwei Bie]

On Fri, Feb 09, 2018 at 03:26:54PM +0100, Maxime Coquelin wrote:
> A deadlock happens when handling VHOST_USER_RESET_OWNER request
> for the same reason the lock is not taken for
> VHOST_USER_GET_VRING_BASE.
> 
> It is safe not to take the lock, as the queues are no more used
> by the application when the virtqueues and the device are reset.
> 
> Fixes: a3688046995f ("vhost: protect active rings from async ring changes")
> Cc: stable@dpdk.org
> 
> Cc: Victor Kaplansky <victork@redhat.com>
> Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>

Reviewed-by: Tiwei Bie <tiwei.bie@intel.com>

Thanks for the work!

Best regards,
Tiwei Bie