Displaying 20 results from an estimated 59 matches for "virtq".
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2015 Jan 28
0
memory barriers in virtq.lua?
Hello Michael,
On Tue, Jan 27, 2015 at 6:01 PM, Michael S. Tsirkin <mst at redhat.com> wrote:
> Hi Nikolay,
> I poked at src/lib/virtio/virtq.lua a bit -
> I was surprised to find no explicit CPU memory
> barriers in the virtq implementation.
> These are typically required when using virtio
> on smp machines - the spec actually mention where
> barriers are necessary.
> Are the barriers implicit somehow for lua?
> I...
2015 Jan 27
2
memory barriers in virtq.lua?
Hi Nikolay,
I poked at src/lib/virtio/virtq.lua a bit -
I was surprised to find no explicit CPU memory
barriers in the virtq implementation.
These are typically required when using virtio
on smp machines - the spec actually mention where
barriers are necessary.
Are the barriers implicit somehow for lua?
I'd be curious to learn.
Thanks,...
2015 Jan 27
2
memory barriers in virtq.lua?
Hi Nikolay,
I poked at src/lib/virtio/virtq.lua a bit -
I was surprised to find no explicit CPU memory
barriers in the virtq implementation.
These are typically required when using virtio
on smp machines - the spec actually mention where
barriers are necessary.
Are the barriers implicit somehow for lua?
I'd be curious to learn.
Thanks,...
2015 Apr 09
1
[dpdk-dev] [snabb-devel] Re: memory barriers in virtq.lua?
Howdy,
On 8 April 2015 at 17:15, Xie, Huawei <huawei.xie at intel.com> wrote:
> luke:
> 1. host read the flag. 2 guest toggles the flag 3.guest checks the used.
> 4. host update used.
> Is this your case?
>
Yep, that is exactly the case I mean.
Cheers,
-Luke
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2015 Apr 09
1
[dpdk-dev] [snabb-devel] Re: memory barriers in virtq.lua?
Howdy,
On 8 April 2015 at 17:15, Xie, Huawei <huawei.xie at intel.com> wrote:
> luke:
> 1. host read the flag. 2 guest toggles the flag 3.guest checks the used.
> 4. host update used.
> Is this your case?
>
Yep, that is exactly the case I mean.
Cheers,
-Luke
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2019 Oct 02
0
virtq questions
On Wed, Oct 02, 2019 at 09:40:11AM +0200, Miklos Szeredi wrote:
> Looking at the ugly retry logic in virtiofs and have some questions.
Hi Miklos,
What are you thinking w.r.t cleanup of retry logic. As of now we put
requests in a list and retry later with the help of a worker.
Other option will probably be block the submitter if queue is full. Make
it sleep, wake up after a while and retry
2019 Oct 02
0
virtq questions
* Miklos Szeredi (miklos at szeredi.hu) wrote:
> Looking at the ugly retry logic in virtiofs and have some questions.
> First one is, where do these features come from:
>
> VIRTIO_F_RING_PACKED
> VIRTIO_RING_F_INDIRECT_DESC
>
> I see that in virtiofs "packed" is off and "indirect" is on. Is this
> guaranteed?
I think the xdindirect is coming from
2015 Apr 08
0
[dpdk-dev] [snabb-devel] Re: memory barriers in virtq.lua?
On 4/7/2015 10:23 PM, Luke Gorrie wrote:
> Hi Michael,
>
> I'm writing to follow up the previous discussion about memory barriers in
> virtio-net device implementations, and Cc'ing the DPDK list because I
> believe this is relevant to them too.
>
> First, thanks again for getting in touch and reviewing our code.
>
> I have now found a missed case where we *do*
2015 Apr 07
0
[snabb-devel] Re: memory barriers in virtq.lua?
On Tue, Apr 07, 2015 at 04:22:42PM +0200, Luke Gorrie wrote:
> Hi Michael,
>
> I'm writing to follow up the previous discussion about memory barriers in
> virtio-net device implementations, and Cc'ing the DPDK list because I believe
> this is relevant to them too.
>
> First, thanks again for getting in touch and reviewing our code.
>
> I have now found a
2019 Oct 03
0
virtq questions
...you elaborate a bit
more that why it is important. Device does not provide any guarantees
that requests will be completed in order of submission. If that's the
case, then submitter can't assume any order in request completion anyway.
>
> This is complicated by the fact that we call virtqueue_add_sgs() under
> spinlock, which is the reason GFP_ATOMIC is used. However GFP_ATOMIC
> can easily fail and that means even if the "indirect_desc" feature is
> turned on a request may use several slots of the ring buffer for a
> single request.
Aha, you are referring to...
2019 Apr 11
4
[RFC 0/3] VirtIO RDMA
...the RDMA/RoCE
> > Virtio Specification and a look forward on possible implementation
> > techniques.
> >
> > Open issues/Todo list:
> > List is huge, this is only start point of the project.
> > Anyway, here is one example of item in the list:
> > - Multi VirtQ: Every QP has two rings and every CQ has one. This means that
> > in order to support for example 32K QPs we will need 64K VirtQ. Not sure
> > that this is reasonable so one option is to have one for all and
> > multiplex the traffic on it. This is not good approach as by de...
2019 Apr 11
4
[RFC 0/3] VirtIO RDMA
...the RDMA/RoCE
> > Virtio Specification and a look forward on possible implementation
> > techniques.
> >
> > Open issues/Todo list:
> > List is huge, this is only start point of the project.
> > Anyway, here is one example of item in the list:
> > - Multi VirtQ: Every QP has two rings and every CQ has one. This means that
> > in order to support for example 32K QPs we will need 64K VirtQ. Not sure
> > that this is reasonable so one option is to have one for all and
> > multiplex the traffic on it. This is not good approach as by de...
2023 Feb 15
1
[PATCH v3] vdpa/mlx5: should not activate virtq object when suspended
Otherwise the virtqueue object to instate could point to invalid address
that was unmapped from the MTT:
mlx5_core 0000:41:04.2: mlx5_cmd_out_err:782:(pid 8321):
CREATE_GENERAL_OBJECT(0xa00) op_mod(0xd) failed, status
bad parameter(0x3), syndrome (0x5fa1c), err(-22)
Fixes: cae15c2ed8e6 ("vdpa/mlx5: Implem...
2023 Feb 08
2
virtio-fs: adding support for multi-queue
...that our setup on
>>>>>>> the virtio-fs device-side (a DPU) does not easily allow multiple cores to
>>>>>>> tend to a single virtio queue.
>>>>>
>>>>> This is an interesting limitation in DPU.
>>>>
>>>> Virtqueues are single-consumer queues anyway. Sharing them between
>>>> multiple threads would be expensive. I think using multiqueue is natural
>>>> and not specific to DPUs.
>>>
>>> Can we create multiple threads (a thread pool) on DPU and let these
>>>...
2023 Feb 16
1
[PATCH v3] vdpa/mlx5: should not activate virtq object when suspended
On Wed, Feb 15, 2023 at 9:31 AM Si-Wei Liu <si-wei.liu at oracle.com> wrote:
>
> Otherwise the virtqueue object to instate could point to invalid address
> that was unmapped from the MTT:
>
> mlx5_core 0000:41:04.2: mlx5_cmd_out_err:782:(pid 8321):
> CREATE_GENERAL_OBJECT(0xa00) op_mod(0xd) failed, status
> bad parameter(0x3), syndrome (0x5fa1c), err(-22)
>
> Fixes: cae1...
2023 Feb 16
1
[PATCH v3] vdpa/mlx5: should not activate virtq object when suspended
On 2/15/2023 8:48 PM, Jason Wang wrote:
> On Wed, Feb 15, 2023 at 9:31 AM Si-Wei Liu <si-wei.liu at oracle.com> wrote:
>> Otherwise the virtqueue object to instate could point to invalid address
>> that was unmapped from the MTT:
>>
>> mlx5_core 0000:41:04.2: mlx5_cmd_out_err:782:(pid 8321):
>> CREATE_GENERAL_OBJECT(0xa00) op_mod(0xd) failed, status
>> bad parameter(0x3), syndrome (0x5fa1c), err(-22...
2019 Apr 22
2
[Qemu-devel] [RFC 0/3] VirtIO RDMA
...ward on possible implementation
> > > > techniques.
> > > >
> > > > Open issues/Todo list:
> > > > List is huge, this is only start point of the project.
> > > > Anyway, here is one example of item in the list:
> > > > - Multi VirtQ: Every QP has two rings and every CQ has one. This means that
> > > > in order to support for example 32K QPs we will need 64K VirtQ. Not sure
> > > > that this is reasonable so one option is to have one for all and
> > > > multiplex the traffic on it. T...
2019 Apr 22
2
[Qemu-devel] [RFC 0/3] VirtIO RDMA
...ward on possible implementation
> > > > techniques.
> > > >
> > > > Open issues/Todo list:
> > > > List is huge, this is only start point of the project.
> > > > Anyway, here is one example of item in the list:
> > > > - Multi VirtQ: Every QP has two rings and every CQ has one. This means that
> > > > in order to support for example 32K QPs we will need 64K VirtQ. Not sure
> > > > that this is reasonable so one option is to have one for all and
> > > > multiplex the traffic on it. T...
2019 Apr 15
4
[RFC 0/3] VirtIO RDMA
...the RDMA/RoCE
> > Virtio Specification and a look forward on possible implementation
> > techniques.
> >
> > Open issues/Todo list:
> > List is huge, this is only start point of the project.
> > Anyway, here is one example of item in the list:
> > - Multi VirtQ: Every QP has two rings and every CQ has one. This means that
> > in order to support for example 32K QPs we will need 64K VirtQ. Not sure
> > that this is reasonable so one option is to have one for all and
> > multiplex the traffic on it. This is not good approach as by de...
2019 Apr 15
4
[RFC 0/3] VirtIO RDMA
...the RDMA/RoCE
> > Virtio Specification and a look forward on possible implementation
> > techniques.
> >
> > Open issues/Todo list:
> > List is huge, this is only start point of the project.
> > Anyway, here is one example of item in the list:
> > - Multi VirtQ: Every QP has two rings and every CQ has one. This means that
> > in order to support for example 32K QPs we will need 64K VirtQ. Not sure
> > that this is reasonable so one option is to have one for all and
> > multiplex the traffic on it. This is not good approach as by de...