diff mbox series

[RFC,v2,4/9] vhost: fix async access

Message ID 20220330134956.18927-5-david.marchand@redhat.com (mailing list archive)
State Superseded, archived
Delegated to: David Marchand
Headers
Series vhost lock annotations |

Commit Message

David Marchand March 30, 2022, 1:49 p.m. UTC 
  vq->async accesses must be protected with vq->access_lock.

Fixes: eb666d24085f ("vhost: fix async unregister deadlock")
Fixes: 0c0935c5f794 ("vhost: allow to check in-flight packets for async vhost")
Cc: stable@dpdk.org

Signed-off-by: David Marchand <david.marchand@redhat.com>
---
 lib/vhost/vhost.c | 25 ++++++++++---------------
 1 file changed, 10 insertions(+), 15 deletions(-)

Comments

Maxime Coquelin March 31, 2022, 8 a.m. UTC | #1 
Hi Jiayu,

On 3/30/22 15:49, David Marchand wrote:
> vq->async accesses must be protected with vq->access_lock.
> 
> Fixes: eb666d24085f ("vhost: fix async unregister deadlock")
> Fixes: 0c0935c5f794 ("vhost: allow to check in-flight packets for async vhost")
> Cc: stable@dpdk.org
> 
> Signed-off-by: David Marchand <david.marchand@redhat.com>
> ---
>   lib/vhost/vhost.c | 25 ++++++++++---------------
>   1 file changed, 10 insertions(+), 15 deletions(-)

Could you please test and review below patch?
We may want to apply it early, before the annotation series is applied.

Thanks!
Maxime

> diff --git a/lib/vhost/vhost.c b/lib/vhost/vhost.c
> index 2f96a28dac..a93e41f314 100644
> --- a/lib/vhost/vhost.c
> +++ b/lib/vhost/vhost.c
> @@ -1753,27 +1753,23 @@ rte_vhost_async_channel_unregister(int vid, uint16_t queue_id)
>   	if (vq == NULL)
>   		return ret;
>   
> -	ret = 0;
> -
> -	if (!vq->async)
> -		return ret;
> -
>   	if (!rte_spinlock_trylock(&vq->access_lock)) {
>   		VHOST_LOG_CONFIG(ERR, "(%s) failed to unregister async channel, virtqueue busy.\n",
>   				dev->ifname);
> -		return -1;
> +		return ret;
>   	}
>   
> -	if (vq->async->pkts_inflight_n) {
> +	if (!vq->async) {
> +		ret = 0;
> +	} else if (vq->async->pkts_inflight_n) {
>   		VHOST_LOG_CONFIG(ERR, "(%s) failed to unregister async channel.\n", dev->ifname);
>   		VHOST_LOG_CONFIG(ERR, "(%s) inflight packets must be completed before unregistration.\n",
>   			dev->ifname);
> -		ret = -1;
> -		goto out;
> +	} else {
> +		vhost_free_async_mem(vq);
> +		ret = 0;
>   	}
>   
> -	vhost_free_async_mem(vq);
> -out:
>   	rte_spinlock_unlock(&vq->access_lock);
>   
>   	return ret;
> @@ -1891,9 +1887,6 @@ rte_vhost_async_get_inflight(int vid, uint16_t queue_id)
>   	if (vq == NULL)
>   		return ret;
>   
> -	if (!vq->async)
> -		return ret;
> -
>   	if (!rte_spinlock_trylock(&vq->access_lock)) {
>   		VHOST_LOG_CONFIG(DEBUG,
>   			"(%s) failed to check in-flight packets. virtqueue busy.\n",
> @@ -1901,7 +1894,9 @@ rte_vhost_async_get_inflight(int vid, uint16_t queue_id)
>   		return ret;
>   	}
>   
> -	ret = vq->async->pkts_inflight_n;
> +	if (vq->async)
> +		ret = vq->async->pkts_inflight_n;
> +
>   	rte_spinlock_unlock(&vq->access_lock);
>   
>   	return ret;
Hu, Jiayu March 31, 2022, 10:23 a.m. UTC | #2 
> -----Original Message-----
> From: Maxime Coquelin <maxime.coquelin@redhat.com>
> Sent: Thursday, March 31, 2022 4:00 PM
> To: David Marchand <david.marchand@redhat.com>; dev@dpdk.org
> Cc: Xia, Chenbo <chenbo.xia@intel.com>; Hu, Jiayu <jiayu.hu@intel.com>;
> Wang, YuanX <yuanx.wang@intel.com>; Ding, Xuan <xuan.ding@intel.com>;
> stable@dpdk.org; Patrick Fu <patrick.fu@intel.com>
> Subject: Re: [RFC PATCH v2 4/9] vhost: fix async access
> 
> Hi Jiayu,
> 
> On 3/30/22 15:49, David Marchand wrote:
> > vq->async accesses must be protected with vq->access_lock.
> >
> > Fixes: eb666d24085f ("vhost: fix async unregister deadlock")
> > Fixes: 0c0935c5f794 ("vhost: allow to check in-flight packets for
> > async vhost")
> > Cc: stable@dpdk.org
> >
> > Signed-off-by: David Marchand <david.marchand@redhat.com>
> > ---
> >   lib/vhost/vhost.c | 25 ++++++++++---------------
> >   1 file changed, 10 insertions(+), 15 deletions(-)
> 
> Could you please test and review below patch?
> We may want to apply it early, before the annotation series is applied.

Sure, I will review them.

Thanks,
Jiayu
> 
> Thanks!
> Maxime
> 
> > diff --git a/lib/vhost/vhost.c b/lib/vhost/vhost.c index
> > 2f96a28dac..a93e41f314 100644
> > --- a/lib/vhost/vhost.c
> > +++ b/lib/vhost/vhost.c
> > @@ -1753,27 +1753,23 @@ rte_vhost_async_channel_unregister(int vid,
> uint16_t queue_id)
> >   	if (vq == NULL)
> >   		return ret;
> >
> > -	ret = 0;
> > -
> > -	if (!vq->async)
> > -		return ret;
> > -
> >   	if (!rte_spinlock_trylock(&vq->access_lock)) {
> >   		VHOST_LOG_CONFIG(ERR, "(%s) failed to unregister async
> channel, virtqueue busy.\n",
> >   				dev->ifname);
> > -		return -1;
> > +		return ret;
> >   	}
> >
> > -	if (vq->async->pkts_inflight_n) {
> > +	if (!vq->async) {
> > +		ret = 0;
> > +	} else if (vq->async->pkts_inflight_n) {
> >   		VHOST_LOG_CONFIG(ERR, "(%s) failed to unregister async
> channel.\n", dev->ifname);
> >   		VHOST_LOG_CONFIG(ERR, "(%s) inflight packets must be
> completed before unregistration.\n",
> >   			dev->ifname);
> > -		ret = -1;
> > -		goto out;
> > +	} else {
> > +		vhost_free_async_mem(vq);
> > +		ret = 0;
> >   	}
> >
> > -	vhost_free_async_mem(vq);
> > -out:
> >   	rte_spinlock_unlock(&vq->access_lock);
> >
> >   	return ret;
> > @@ -1891,9 +1887,6 @@ rte_vhost_async_get_inflight(int vid, uint16_t
> queue_id)
> >   	if (vq == NULL)
> >   		return ret;
> >
> > -	if (!vq->async)
> > -		return ret;
> > -
> >   	if (!rte_spinlock_trylock(&vq->access_lock)) {
> >   		VHOST_LOG_CONFIG(DEBUG,
> >   			"(%s) failed to check in-flight packets. virtqueue
> busy.\n", @@
> > -1901,7 +1894,9 @@ rte_vhost_async_get_inflight(int vid, uint16_t
> queue_id)
> >   		return ret;
> >   	}
> >
> > -	ret = vq->async->pkts_inflight_n;
> > +	if (vq->async)
> > +		ret = vq->async->pkts_inflight_n;
> > +
> >   	rte_spinlock_unlock(&vq->access_lock);
> >
> >   	return ret;
Sunil Pai G April 4, 2022, 6:57 a.m. UTC | #3 
> -----Original Message-----
> From: David Marchand <david.marchand@redhat.com>
> Sent: Wednesday, March 30, 2022 7:20 PM
> To: dev@dpdk.org
> Cc: maxime.coquelin@redhat.com; Xia, Chenbo <chenbo.xia@intel.com>; Hu,
> Jiayu <jiayu.hu@intel.com>; Wang, YuanX <yuanx.wang@intel.com>; Ding, Xuan
> <xuan.ding@intel.com>; stable@dpdk.org; Patrick Fu <patrick.fu@intel.com>
> Subject: [RFC PATCH v2 4/9] vhost: fix async access
> 
> vq->async accesses must be protected with vq->access_lock.
> 
> Fixes: eb666d24085f ("vhost: fix async unregister deadlock")
> Fixes: 0c0935c5f794 ("vhost: allow to check in-flight packets for async
> vhost")
> Cc: stable@dpdk.org
> 
> Signed-off-by: David Marchand <david.marchand@redhat.com>
> ---
>  lib/vhost/vhost.c | 25 ++++++++++---------------
>  1 file changed, 10 insertions(+), 15 deletions(-)



Thanks for the fix, David.
Tested the changes for rte_vhost_async_get_inflight, works as expected. 
Although I couldn't test,  the changes for rte_vhost_async_channel_unregister looks good to me .

Based on that,
Acked-by: Sunil Pai G <sunil.pai.g@intel.com>
diff mbox series

Patch

diff --git a/lib/vhost/vhost.c b/lib/vhost/vhost.c
index 2f96a28dac..a93e41f314 100644
--- a/lib/vhost/vhost.c
+++ b/lib/vhost/vhost.c
@@ -1753,27 +1753,23 @@  rte_vhost_async_channel_unregister(int vid, uint16_t queue_id)
 	if (vq == NULL)
 		return ret;
 
-	ret = 0;
-
-	if (!vq->async)
-		return ret;
-
 	if (!rte_spinlock_trylock(&vq->access_lock)) {
 		VHOST_LOG_CONFIG(ERR, "(%s) failed to unregister async channel, virtqueue busy.\n",
 				dev->ifname);
-		return -1;
+		return ret;
 	}
 
-	if (vq->async->pkts_inflight_n) {
+	if (!vq->async) {
+		ret = 0;
+	} else if (vq->async->pkts_inflight_n) {
 		VHOST_LOG_CONFIG(ERR, "(%s) failed to unregister async channel.\n", dev->ifname);
 		VHOST_LOG_CONFIG(ERR, "(%s) inflight packets must be completed before unregistration.\n",
 			dev->ifname);
-		ret = -1;
-		goto out;
+	} else {
+		vhost_free_async_mem(vq);
+		ret = 0;
 	}
 
-	vhost_free_async_mem(vq);
-out:
 	rte_spinlock_unlock(&vq->access_lock);
 
 	return ret;
@@ -1891,9 +1887,6 @@  rte_vhost_async_get_inflight(int vid, uint16_t queue_id)
 	if (vq == NULL)
 		return ret;
 
-	if (!vq->async)
-		return ret;
-
 	if (!rte_spinlock_trylock(&vq->access_lock)) {
 		VHOST_LOG_CONFIG(DEBUG,
 			"(%s) failed to check in-flight packets. virtqueue busy.\n",
@@ -1901,7 +1894,9 @@  rte_vhost_async_get_inflight(int vid, uint16_t queue_id)
 		return ret;
 	}
 
-	ret = vq->async->pkts_inflight_n;
+	if (vq->async)
+		ret = vq->async->pkts_inflight_n;
+
 	rte_spinlock_unlock(&vq->access_lock);
 
 	return ret;