diff mbox series

vhost: fix vhost user virtqueue not accessable

Message ID 20191025162042.71687-1-yong.liu@intel.com (mailing list archive)
State Superseded, archived
Delegated to: Maxime Coquelin
Headers
Series vhost: fix vhost user virtqueue not accessable |

Checks

Context Check Description
ci/checkpatch warning coding style issues
ci/iol-intel-Performance success Performance Testing PASS
ci/iol-compilation success Compile Testing PASS
ci/iol-mellanox-Performance success Performance Testing PASS
ci/Intel-compilation success Compilation OK

Commit Message

Marvin Liu Oct. 25, 2019, 4:20 p.m. UTC 
  Log feature is disabled in vhost user, so that log address was invalid
when checking. Add feature bit check can skip useless address check.

Fixes: 04cfc7fdbfca ("vhost: translate incoming log address to gpa")

Signed-off-by: Marvin Liu <yong.liu@intel.com>
---
 lib/librte_vhost/vhost_user.c | 16 +++++++++-------
 1 file changed, 9 insertions(+), 7 deletions(-)

Comments

Adrian Moreno Oct. 25, 2019, 12:20 p.m. UTC | #1 
Hi Marvin,

On 10/25/19 6:20 PM, Marvin Liu wrote:
> Log feature is disabled in vhost user, so that log address was invalid
> when checking. Add feature bit check can skip useless address check.
>
Just so I understand, what conditions is the log address invalid?

> Fixes: 04cfc7fdbfca ("vhost: translate incoming log address to gpa")
> 
> Signed-off-by: Marvin Liu <yong.liu@intel.com>
> ---
>  lib/librte_vhost/vhost_user.c | 16 +++++++++-------
>  1 file changed, 9 insertions(+), 7 deletions(-)
> 
> diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c
> index 61ef699ac..0407fdc29 100644
> --- a/lib/librte_vhost/vhost_user.c
> +++ b/lib/librte_vhost/vhost_user.c
> @@ -741,13 +741,15 @@ translate_ring_addresses(struct virtio_net *dev, int vq_index)
>  		vq->last_avail_idx = vq->used->idx;
>  	}
>  
> -	vq->log_guest_addr =
> -		translate_log_addr(dev, vq, addr->log_guest_addr);
> -	if (vq->log_guest_addr == 0) {
> -		RTE_LOG(DEBUG, VHOST_CONFIG,
> -			"(%d) failed to map log_guest_addr .\n",
> -			dev->vid);
> -		return dev;
> +	if (dev->features & (1ULL << VHOST_F_LOG_ALL)) {
> +		vq->log_guest_addr =
> +			translate_log_addr(dev, vq, addr->log_guest_addr);

VHOST_F_LOG_ALL is only negotiated once the migration has started (at least from
qemu's perspective).
That means that we will postponing the translation  of the log address to the
vhost_user_set_vring_addr() call that follows the VHOST_F_LOG_ALL enabling. In
that call there are (at least) two things that could go wrong and lead to a
migration failure:
- If VHOST_USER_F_PROTOCOL_FEATURES is not enabled, the address won't be translated:

vhost_user:795
	if ((vq->enabled && (dev->features &
				(1ULL << VHOST_USER_F_PROTOCOL_FEATURES))) ||
			access_ok) {
		dev = translate_ring_addresses(dev, msg->payload.addr.index);
		if (!dev)
			return RTE_VHOST_MSG_RESULT_ERR;

		*pdev = dev;
	}

- If the IOMMU is enabled and there's a miss, we would have to wait for the
IOTLB_UPDATE and during that time, there would be failed accesses to the (still
untranslated) log address.



> +		if (vq->log_guest_addr == 0) {
> +			RTE_LOG(DEBUG, VHOST_CONFIG,
> +				"(%d) failed to map log_guest_addr .\n",
> +				dev->vid);
> +			return dev;
> +		}
>  	}
>  	vq->access_ok = 1;
>  
> 
Thanks,
Adrian
Marvin Liu Oct. 28, 2019, 2:13 a.m. UTC | #2 
> -----Original Message-----
> From: Adrian Moreno [mailto:amorenoz@redhat.com]
> Sent: Friday, October 25, 2019 8:21 PM
> To: Liu, Yong <yong.liu@intel.com>; maxime.coquelin@redhat.com; Bie, Tiwei
> <tiwei.bie@intel.com>; Wang, Zhihong <zhihong.wang@intel.com>
> Cc: dev@dpdk.org
> Subject: Re: [PATCH] vhost: fix vhost user virtqueue not accessable
> 
> Hi Marvin,
> 
> On 10/25/19 6:20 PM, Marvin Liu wrote:
> > Log feature is disabled in vhost user, so that log address was invalid
> > when checking. Add feature bit check can skip useless address check.
> >
> Just so I understand, what conditions is the log address invalid?
> 
> > Fixes: 04cfc7fdbfca ("vhost: translate incoming log address to gpa")
> >
> > Signed-off-by: Marvin Liu <yong.liu@intel.com>
> > ---
> >  lib/librte_vhost/vhost_user.c | 16 +++++++++-------
> >  1 file changed, 9 insertions(+), 7 deletions(-)
> >
> > diff --git a/lib/librte_vhost/vhost_user.c
> b/lib/librte_vhost/vhost_user.c
> > index 61ef699ac..0407fdc29 100644
> > --- a/lib/librte_vhost/vhost_user.c
> > +++ b/lib/librte_vhost/vhost_user.c
> > @@ -741,13 +741,15 @@ translate_ring_addresses(struct virtio_net *dev,
> int vq_index)
> >  		vq->last_avail_idx = vq->used->idx;
> >  	}
> >
> > -	vq->log_guest_addr =
> > -		translate_log_addr(dev, vq, addr->log_guest_addr);
> > -	if (vq->log_guest_addr == 0) {
> > -		RTE_LOG(DEBUG, VHOST_CONFIG,
> > -			"(%d) failed to map log_guest_addr .\n",
> > -			dev->vid);
> > -		return dev;
> > +	if (dev->features & (1ULL << VHOST_F_LOG_ALL)) {
> > +		vq->log_guest_addr =
> > +			translate_log_addr(dev, vq, addr->log_guest_addr);
> 
> VHOST_F_LOG_ALL is only negotiated once the migration has started (at least
> from
> qemu's perspective).
> That means that we will postponing the translation  of the log address to
> the
> vhost_user_set_vring_addr() call that follows the VHOST_F_LOG_ALL enabling.
> In
> that call there are (at least) two things that could go wrong and lead to a
> migration failure:
> - If VHOST_USER_F_PROTOCOL_FEATURES is not enabled, the address won't be
> translated:
> 
> vhost_user:795
> 	if ((vq->enabled && (dev->features &
> 				(1ULL << VHOST_USER_F_PROTOCOL_FEATURES))) ||
> 			access_ok) {
> 		dev = translate_ring_addresses(dev, msg->payload.addr.index);
> 		if (!dev)
> 			return RTE_VHOST_MSG_RESULT_ERR;
> 
> 		*pdev = dev;
> 	}
> 
> - If the IOMMU is enabled and there's a miss, we would have to wait for the
> IOTLB_UPDATE and during that time, there would be failed accesses to the
> (still
> untranslated) log address.
> 
> 

Thanks, Adrian. 
Log address can be zero when logging is not enabled.
How about add other criteria after translation? Log address will be translated anyway and not affect vq status.

        vq->log_guest_addr =
                translate_log_addr(dev, vq, addr->log_guest_addr);
-       if (vq->log_guest_addr == 0) {
+       if (vq->log_guest_addr == 0 && addr->flags) {
                RTE_LOG(DEBUG, VHOST_CONFIG,
                        "(%d) failed to map log_guest_addr .\n",
                        dev->vid);
                return dev;
        }

Meanwhile, log address of packed ring is fixed to zero. Is any special reason to do that? 

Regards,
Marvin

> 
> > +		if (vq->log_guest_addr == 0) {
> > +			RTE_LOG(DEBUG, VHOST_CONFIG,
> > +				"(%d) failed to map log_guest_addr .\n",
> > +				dev->vid);
> > +			return dev;
> > +		}
> >  	}
> >  	vq->access_ok = 1;
> >
> >
> Thanks,
> Adrian
Adrian Moreno Oct. 29, 2019, 10:02 a.m. UTC | #3 
On 10/28/19 3:13 AM, Liu, Yong wrote:
> 
> 
>> -----Original Message-----
>> From: Adrian Moreno [mailto:amorenoz@redhat.com]
>> Sent: Friday, October 25, 2019 8:21 PM
>> To: Liu, Yong <yong.liu@intel.com>; maxime.coquelin@redhat.com; Bie, Tiwei
>> <tiwei.bie@intel.com>; Wang, Zhihong <zhihong.wang@intel.com>
>> Cc: dev@dpdk.org
>> Subject: Re: [PATCH] vhost: fix vhost user virtqueue not accessable
>>
>> Hi Marvin,
>>
>> On 10/25/19 6:20 PM, Marvin Liu wrote:
>>> Log feature is disabled in vhost user, so that log address was invalid
>>> when checking. Add feature bit check can skip useless address check.
>>>
>> Just so I understand, what conditions is the log address invalid?
>>
>>> Fixes: 04cfc7fdbfca ("vhost: translate incoming log address to gpa")
>>>
>>> Signed-off-by: Marvin Liu <yong.liu@intel.com>
>>> ---
>>>  lib/librte_vhost/vhost_user.c | 16 +++++++++-------
>>>  1 file changed, 9 insertions(+), 7 deletions(-)
>>>
>>> diff --git a/lib/librte_vhost/vhost_user.c
>> b/lib/librte_vhost/vhost_user.c
>>> index 61ef699ac..0407fdc29 100644
>>> --- a/lib/librte_vhost/vhost_user.c
>>> +++ b/lib/librte_vhost/vhost_user.c
>>> @@ -741,13 +741,15 @@ translate_ring_addresses(struct virtio_net *dev,
>> int vq_index)
>>>  		vq->last_avail_idx = vq->used->idx;
>>>  	}
>>>
>>> -	vq->log_guest_addr =
>>> -		translate_log_addr(dev, vq, addr->log_guest_addr);
>>> -	if (vq->log_guest_addr == 0) {
>>> -		RTE_LOG(DEBUG, VHOST_CONFIG,
>>> -			"(%d) failed to map log_guest_addr .\n",
>>> -			dev->vid);
>>> -		return dev;
>>> +	if (dev->features & (1ULL << VHOST_F_LOG_ALL)) {
>>> +		vq->log_guest_addr =
>>> +			translate_log_addr(dev, vq, addr->log_guest_addr);
>>
>> VHOST_F_LOG_ALL is only negotiated once the migration has started (at least
>> from
>> qemu's perspective).
>> That means that we will postponing the translation  of the log address to
>> the
>> vhost_user_set_vring_addr() call that follows the VHOST_F_LOG_ALL enabling.
>> In
>> that call there are (at least) two things that could go wrong and lead to a
>> migration failure:
>> - If VHOST_USER_F_PROTOCOL_FEATURES is not enabled, the address won't be
>> translated:
>>
>> vhost_user:795
>> 	if ((vq->enabled && (dev->features &
>> 				(1ULL << VHOST_USER_F_PROTOCOL_FEATURES))) ||
>> 			access_ok) {
>> 		dev = translate_ring_addresses(dev, msg->payload.addr.index);
>> 		if (!dev)
>> 			return RTE_VHOST_MSG_RESULT_ERR;
>>
>> 		*pdev = dev;
>> 	}
>>
>> - If the IOMMU is enabled and there's a miss, we would have to wait for the
>> IOTLB_UPDATE and during that time, there would be failed accesses to the
>> (still
>> untranslated) log address.
>>
>>
> 
> Thanks, Adrian. 
> Log address can be zero when logging is not enabled.
> How about add other criteria after translation? Log address will be translated anyway and not affect vq status.
> 
>         vq->log_guest_addr =
>                 translate_log_addr(dev, vq, addr->log_guest_addr);
> -       if (vq->log_guest_addr == 0) {
> +       if (vq->log_guest_addr == 0 && addr->flags) {
>                 RTE_LOG(DEBUG, VHOST_CONFIG,
>                         "(%d) failed to map log_guest_addr .\n",
>                         dev->vid);
>                 return dev;
>         }
> 
That makes perfect sense IMHO. Thank you.

> Meanwhile, log address of packed ring is fixed to zero. Is any special reason to do that? 
> 
No idea to be honest.

Thanks.
Adrian
> Regards,
> Marvin
> 
>>
>>> +		if (vq->log_guest_addr == 0) {
>>> +			RTE_LOG(DEBUG, VHOST_CONFIG,
>>> +				"(%d) failed to map log_guest_addr .\n",
>>> +				dev->vid);
>>> +			return dev;
>>> +		}
>>>  	}
>>>  	vq->access_ok = 1;
>>>
>>>
>> Thanks,
>> Adrian
diff mbox series

Patch

diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c
index 61ef699ac..0407fdc29 100644
--- a/lib/librte_vhost/vhost_user.c
+++ b/lib/librte_vhost/vhost_user.c
@@ -741,13 +741,15 @@  translate_ring_addresses(struct virtio_net *dev, int vq_index)
 		vq->last_avail_idx = vq->used->idx;
 	}
 
-	vq->log_guest_addr =
-		translate_log_addr(dev, vq, addr->log_guest_addr);
-	if (vq->log_guest_addr == 0) {
-		RTE_LOG(DEBUG, VHOST_CONFIG,
-			"(%d) failed to map log_guest_addr .\n",
-			dev->vid);
-		return dev;
+	if (dev->features & (1ULL << VHOST_F_LOG_ALL)) {
+		vq->log_guest_addr =
+			translate_log_addr(dev, vq, addr->log_guest_addr);
+		if (vq->log_guest_addr == 0) {
+			RTE_LOG(DEBUG, VHOST_CONFIG,
+				"(%d) failed to map log_guest_addr .\n",
+				dev->vid);
+			return dev;
+		}
 	}
 	vq->access_ok = 1;