From: Antonio Di Bacco <a.dibacco.ks@gmail.com>
To: Dmitry Kozlyuk <dmitry.kozliuk@gmail.com>
Cc: users@dpdk.org
Subject: Re: Getting mbuf pointer from buf_addr pointer
Date: Tue, 12 Jul 2022 12:30:53 +0200 [thread overview]
Message-ID: <CAO8pfFmMdsX2k2AsFH5sk+ukY=QLO3EpDy+Y2U2r_DKdeEVLqg@mail.gmail.com> (raw)
In-Reply-To: <20220712113234.1209dd36@sovereign>
I was asked to reproduce the exact same behaviour of a library that
used VMDQ queues without DPDK.
Now this library offered an API to allocate a buffer for a packet and
returned an address where the application could write its data.
void* vmdqNew (vmdqUidPOOLt* p);
I implemented the same API to allocate an MBUF from a pool and I also
return the right address as a void* but then to transmit the packet I
need the address of the MBUF for the tx_burst API and I don't have it.
On Tue, Jul 12, 2022 at 10:32 AM Dmitry Kozlyuk
<dmitry.kozliuk@gmail.com> wrote:
>
> 2022-07-11 11:21 (UTC+0200), Antonio Di Bacco:
> > Is there any API that allows me to get the MBUF pointer given its
> > buf_addr pointer?
>
> No.
>
> How did you come across this need?
> Sounds like an app design flaw.
> What is the original problem you're solving?
>
> P.S. It may be possible in specific cases when you know (from code)
> how mempool sets buf_addr for a given mbuf,
> and that PMDs don't change buf_addr with the used set of offloads.
> Apparently, this approach would be extremely brittle and dangerous.
next prev parent reply other threads:[~2022-07-12 10:31 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-07-11 9:21 Antonio Di Bacco
2022-07-12 8:32 ` Dmitry Kozlyuk
2022-07-12 10:30 ` Antonio Di Bacco [this message]
2022-07-12 11:22 ` Dmitry Kozlyuk
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