* [dpdk-dev] [PATCH] vhost: fix invalid use of stored last used index
@ 2021-05-14 16:02 Balazs Nemeth
2021-05-15 6:10 ` David Marchand
` (2 more replies)
0 siblings, 3 replies; 6+ messages in thread
From: Balazs Nemeth @ 2021-05-14 16:02 UTC (permalink / raw)
To: bnemeth, dev, weix.ling
The optimization introduced by commit d18db8049c7c ("vhost: read last
used index once") didn't account for the fact that
vhost_flush_enqueue_shadow_packed increments the last_used_idx. For this
reason, store last_used_idx after the potential call to
vhost_flush_enqueue_shadow_packed.
Fixes: d18db8049c7c ("vhost: read last used index once")
Signed-off-by: Balazs Nemeth <bnemeth@redhat.com>
---
lib/vhost/virtio_net.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/lib/vhost/virtio_net.c b/lib/vhost/virtio_net.c
index abfd67d38c..8da8a86a10 100644
--- a/lib/vhost/virtio_net.c
+++ b/lib/vhost/virtio_net.c
@@ -218,14 +218,17 @@ vhost_flush_enqueue_batch_packed(struct virtio_net *dev,
{
uint16_t i;
uint16_t flags;
- uint16_t last_used_idx = vq->last_used_idx;
- struct vring_packed_desc *desc_base = &vq->desc_packed[last_used_idx];
+ uint16_t last_used_idx;
+ struct vring_packed_desc *desc_base;
if (vq->shadow_used_idx) {
do_data_copy_enqueue(dev, vq);
vhost_flush_enqueue_shadow_packed(dev, vq);
}
+ last_used_idx = vq->last_used_idx;
+ desc_base = &vq->desc_packed[last_used_idx];
+
flags = PACKED_DESC_ENQUEUE_USED_FLAG(vq->used_wrap_counter);
vhost_for_each_try_unroll(i, 0, PACKED_BATCH_SIZE) {
--
2.30.2
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [dpdk-dev] [PATCH] vhost: fix invalid use of stored last used index
2021-05-14 16:02 [dpdk-dev] [PATCH] vhost: fix invalid use of stored last used index Balazs Nemeth
@ 2021-05-15 6:10 ` David Marchand
2021-05-17 7:37 ` Maxime Coquelin
2021-05-18 8:03 ` Xia, Chenbo
2 siblings, 0 replies; 6+ messages in thread
From: David Marchand @ 2021-05-15 6:10 UTC (permalink / raw)
To: Balazs Nemeth; +Cc: dev, Wei Ling
On Fri, May 14, 2021 at 6:02 PM Balazs Nemeth <bnemeth@redhat.com> wrote:
>
> The optimization introduced by commit d18db8049c7c ("vhost: read last
> used index once") didn't account for the fact that
> vhost_flush_enqueue_shadow_packed increments the last_used_idx. For this
> reason, store last_used_idx after the potential call to
> vhost_flush_enqueue_shadow_packed.
>
Bugzilla ID: 699
> Fixes: d18db8049c7c ("vhost: read last used index once")
> Signed-off-by: Balazs Nemeth <bnemeth@redhat.com>
Reviewed-by: David Marchand <david.marchand@redhat.com>
--
David Marchand
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [dpdk-dev] [PATCH] vhost: fix invalid use of stored last used index
2021-05-14 16:02 [dpdk-dev] [PATCH] vhost: fix invalid use of stored last used index Balazs Nemeth
2021-05-15 6:10 ` David Marchand
@ 2021-05-17 7:37 ` Maxime Coquelin
2021-05-17 10:07 ` Ling, WeiX
2021-05-18 8:03 ` Xia, Chenbo
2 siblings, 1 reply; 6+ messages in thread
From: Maxime Coquelin @ 2021-05-17 7:37 UTC (permalink / raw)
To: Balazs Nemeth, dev, weix.ling
Hi Ling,
On 5/14/21 6:02 PM, Balazs Nemeth wrote:
> The optimization introduced by commit d18db8049c7c ("vhost: read last
> used index once") didn't account for the fact that
> vhost_flush_enqueue_shadow_packed increments the last_used_idx. For this
> reason, store last_used_idx after the potential call to
> vhost_flush_enqueue_shadow_packed.
>
> Fixes: d18db8049c7c ("vhost: read last used index once")
> Signed-off-by: Balazs Nemeth <bnemeth@redhat.com>
> ---
> lib/vhost/virtio_net.c | 7 +++++--
> 1 file changed, 5 insertions(+), 2 deletions(-)
>
> diff --git a/lib/vhost/virtio_net.c b/lib/vhost/virtio_net.c
> index abfd67d38c..8da8a86a10 100644
> --- a/lib/vhost/virtio_net.c
> +++ b/lib/vhost/virtio_net.c
> @@ -218,14 +218,17 @@ vhost_flush_enqueue_batch_packed(struct virtio_net *dev,
> {
> uint16_t i;
> uint16_t flags;
> - uint16_t last_used_idx = vq->last_used_idx;
> - struct vring_packed_desc *desc_base = &vq->desc_packed[last_used_idx];
> + uint16_t last_used_idx;
> + struct vring_packed_desc *desc_base;
>
> if (vq->shadow_used_idx) {
> do_data_copy_enqueue(dev, vq);
> vhost_flush_enqueue_shadow_packed(dev, vq);
> }
>
> + last_used_idx = vq->last_used_idx;
> + desc_base = &vq->desc_packed[last_used_idx];
> +
> flags = PACKED_DESC_ENQUEUE_USED_FLAG(vq->used_wrap_counter);
>
> vhost_for_each_try_unroll(i, 0, PACKED_BATCH_SIZE) {
>
Could you please confirm the patch fixes the issue you reported?
Thanks,
Maxime
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [dpdk-dev] [PATCH] vhost: fix invalid use of stored last used index
2021-05-17 7:37 ` Maxime Coquelin
@ 2021-05-17 10:07 ` Ling, WeiX
2021-05-17 10:46 ` Maxime Coquelin
0 siblings, 1 reply; 6+ messages in thread
From: Ling, WeiX @ 2021-05-17 10:07 UTC (permalink / raw)
To: Maxime Coquelin, Balazs Nemeth, dev
> -----Original Message-----
> From: Maxime Coquelin <maxime.coquelin@redhat.com>
> Sent: Monday, May 17, 2021 03:38 PM
> To: Balazs Nemeth <bnemeth@redhat.com>; dev@dpdk.org; Ling, WeiX
> <weix.ling@intel.com>
> Subject: Re: [dpdk-dev] [PATCH] vhost: fix invalid use of stored last used
> index
>
> Hi Ling,
>
>
> On 5/14/21 6:02 PM, Balazs Nemeth wrote:
> > The optimization introduced by commit d18db8049c7c ("vhost: read last
> > used index once") didn't account for the fact that
> > vhost_flush_enqueue_shadow_packed increments the last_used_idx. For
> > this reason, store last_used_idx after the potential call to
> > vhost_flush_enqueue_shadow_packed.
> >
> > Fixes: d18db8049c7c ("vhost: read last used index once")
> > Signed-off-by: Balazs Nemeth <bnemeth@redhat.com>
> > ---
> > lib/vhost/virtio_net.c | 7 +++++--
> > 1 file changed, 5 insertions(+), 2 deletions(-)
> >
> > diff --git a/lib/vhost/virtio_net.c b/lib/vhost/virtio_net.c index
> > abfd67d38c..8da8a86a10 100644
> > --- a/lib/vhost/virtio_net.c
> > +++ b/lib/vhost/virtio_net.c
> > @@ -218,14 +218,17 @@ vhost_flush_enqueue_batch_packed(struct
> > virtio_net *dev, {
> > uint16_t i;
> > uint16_t flags;
> > - uint16_t last_used_idx = vq->last_used_idx;
> > - struct vring_packed_desc *desc_base = &vq-
> >desc_packed[last_used_idx];
> > + uint16_t last_used_idx;
> > + struct vring_packed_desc *desc_base;
> >
> > if (vq->shadow_used_idx) {
> > do_data_copy_enqueue(dev, vq);
> > vhost_flush_enqueue_shadow_packed(dev, vq);
> > }
> >
> > + last_used_idx = vq->last_used_idx;
> > + desc_base = &vq->desc_packed[last_used_idx];
> > +
> > flags = PACKED_DESC_ENQUEUE_USED_FLAG(vq-
> >used_wrap_counter);
> >
> > vhost_for_each_try_unroll(i, 0, PACKED_BATCH_SIZE) {
> >
>
> Could you please confirm the patch fixes the issue you reported?
>
> Thanks,
> Maxime
Hi Maxime,
Apply your patch https://patches.dpdk.org/project/dpdk/patch/83fa6253725a7bc69bccb7897f380422354a2898.1621008025.git.bnemeth@redhat.com/ based on DPDK-21.05-rc3(7989b7e7da9b), tested PASSED.
Regards,
Ling Wei
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [dpdk-dev] [PATCH] vhost: fix invalid use of stored last used index
2021-05-17 10:07 ` Ling, WeiX
@ 2021-05-17 10:46 ` Maxime Coquelin
0 siblings, 0 replies; 6+ messages in thread
From: Maxime Coquelin @ 2021-05-17 10:46 UTC (permalink / raw)
To: Ling, WeiX, Balazs Nemeth, dev
On 5/17/21 12:07 PM, Ling, WeiX wrote:
>> -----Original Message-----
>> From: Maxime Coquelin <maxime.coquelin@redhat.com>
>> Sent: Monday, May 17, 2021 03:38 PM
>> To: Balazs Nemeth <bnemeth@redhat.com>; dev@dpdk.org; Ling, WeiX
>> <weix.ling@intel.com>
>> Subject: Re: [dpdk-dev] [PATCH] vhost: fix invalid use of stored last used
>> index
>>
>> Hi Ling,
>>
>>
>> On 5/14/21 6:02 PM, Balazs Nemeth wrote:
>>> The optimization introduced by commit d18db8049c7c ("vhost: read last
>>> used index once") didn't account for the fact that
>>> vhost_flush_enqueue_shadow_packed increments the last_used_idx. For
>>> this reason, store last_used_idx after the potential call to
>>> vhost_flush_enqueue_shadow_packed.
>>>
>>> Fixes: d18db8049c7c ("vhost: read last used index once")
>>> Signed-off-by: Balazs Nemeth <bnemeth@redhat.com>
>>> ---
>>> lib/vhost/virtio_net.c | 7 +++++--
>>> 1 file changed, 5 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/lib/vhost/virtio_net.c b/lib/vhost/virtio_net.c index
>>> abfd67d38c..8da8a86a10 100644
>>> --- a/lib/vhost/virtio_net.c
>>> +++ b/lib/vhost/virtio_net.c
>>> @@ -218,14 +218,17 @@ vhost_flush_enqueue_batch_packed(struct
>>> virtio_net *dev, {
>>> uint16_t i;
>>> uint16_t flags;
>>> - uint16_t last_used_idx = vq->last_used_idx;
>>> - struct vring_packed_desc *desc_base = &vq-
>>> desc_packed[last_used_idx];
>>> + uint16_t last_used_idx;
>>> + struct vring_packed_desc *desc_base;
>>>
>>> if (vq->shadow_used_idx) {
>>> do_data_copy_enqueue(dev, vq);
>>> vhost_flush_enqueue_shadow_packed(dev, vq);
>>> }
>>>
>>> + last_used_idx = vq->last_used_idx;
>>> + desc_base = &vq->desc_packed[last_used_idx];
>>> +
>>> flags = PACKED_DESC_ENQUEUE_USED_FLAG(vq-
>>> used_wrap_counter);
>>>
>>> vhost_for_each_try_unroll(i, 0, PACKED_BATCH_SIZE) {
>>>
>>
>> Could you please confirm the patch fixes the issue you reported?
>>
>> Thanks,
>> Maxime
>
> Hi Maxime,
>
> Apply your patch https://patches.dpdk.org/project/dpdk/patch/83fa6253725a7bc69bccb7897f380422354a2898.1621008025.git.bnemeth@redhat.com/ based on DPDK-21.05-rc3(7989b7e7da9b), tested PASSED.
Thanks for testing with the patch.
Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Tested-by: Wei Ling <weix.ling@intel.com>
Thanks,
Maxime
Thanks,
Maxime
> Regards,
> Ling Wei
>
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [dpdk-dev] [PATCH] vhost: fix invalid use of stored last used index
2021-05-14 16:02 [dpdk-dev] [PATCH] vhost: fix invalid use of stored last used index Balazs Nemeth
2021-05-15 6:10 ` David Marchand
2021-05-17 7:37 ` Maxime Coquelin
@ 2021-05-18 8:03 ` Xia, Chenbo
2 siblings, 0 replies; 6+ messages in thread
From: Xia, Chenbo @ 2021-05-18 8:03 UTC (permalink / raw)
To: Balazs Nemeth, dev, Ling, WeiX
> -----Original Message-----
> From: dev <dev-bounces@dpdk.org> On Behalf Of Balazs Nemeth
> Sent: Saturday, May 15, 2021 12:02 AM
> To: bnemeth@redhat.com; dev@dpdk.org; Ling, WeiX <weix.ling@intel.com>
> Subject: [dpdk-dev] [PATCH] vhost: fix invalid use of stored last used index
>
> The optimization introduced by commit d18db8049c7c ("vhost: read last
> used index once") didn't account for the fact that
> vhost_flush_enqueue_shadow_packed increments the last_used_idx. For this
> reason, store last_used_idx after the potential call to
> vhost_flush_enqueue_shadow_packed.
>
> Fixes: d18db8049c7c ("vhost: read last used index once")
> Signed-off-by: Balazs Nemeth <bnemeth@redhat.com>
> ---
> 2.30.2
Applied to next-virtio/main, thanks
^ permalink raw reply [flat|nested] 6+ messages in thread
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2021-05-14 16:02 [dpdk-dev] [PATCH] vhost: fix invalid use of stored last used index Balazs Nemeth
2021-05-15 6:10 ` David Marchand
2021-05-17 7:37 ` Maxime Coquelin
2021-05-17 10:07 ` Ling, WeiX
2021-05-17 10:46 ` Maxime Coquelin
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