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From: "Burakov, Anatoly" <anatoly.burakov@intel.com>
To: Ciara Loftus <ciara.loftus@intel.com>, <dev@dpdk.org>
Subject: Re: [PATCH] net/iavf: fix reset race condition
Date: Fri, 25 Sep 2026 12:46:16 +0200	[thread overview]
Message-ID: <3048d3a5-c148-4ad9-afb6-9e334a53cd4f@intel.com> (raw)
In-Reply-To: <20260924084152.11089-1-ciara.loftus@intel.com>

On 9/24/2026 10:41 AM, Ciara Loftus wrote:
> iavf_handle_hw_reset() can be called concurrently from the iavf-event
> thread handling RTE_ETH_EVENT_INTR_RESET and from any thread calling
> rte_pmd_iavf_reinit() (VF-initiated reset), with no synchronisation
> between the two. Make in_reset_recovery atomic and use it as a guard
> so only one reset runs at a time.
> 
> Fixes: 28a1a72eac26 ("net/iavf: add VF initiated reset")
> 
> Signed-off-by: Ciara Loftus <ciara.loftus@intel.com>
> ---

There's an AI review comment about a potential stale in_reset_recovery 
state when init/uninit fails in certain cases. I've taken the liberty to 
check this against the code, and it seems to be a false positive.

My own AI review flagged the following:

```
iavf_ethdev.c:3747: after observing false, this function reads 
start_pending, dev_started, link_up that the reset thread wrote before 
its release-store. A relaxed load does not formally synchronize with 
that release, so on weakly-ordered CPUs those reads could be stale. Use 
rte_memory_order_acquire here.

iavf_ethdev.c:3547-3548: vf->pf_reset_in_progress = false is written 
after the release-store, so it is not covered by it. A concurrent 
dev_close() on another thread that sees the flag cleared could still see 
pf_reset_in_progress == true and skip iavf_vf_reset()/flow flush. Swap 
the two lines.
```

However, if we're running two dev_close() calls concurrently we've got 
way bigger problems so I don't think the second finding is meaningful. 
The first one may be a "correctness" issue but not blocking either.

So, LGTM (with or without the above suggested fixed)

Acked-by: Anatoly Burakov <anatoly.burakov@intel.com>

-- 
Thanks,
Anatoly

  reply	other threads:[~2026-09-25 10:46 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-09-24  8:41 [PATCH] net/iavf: fix reset race condition Ciara Loftus
2026-09-25 10:46 ` Burakov, Anatoly [this message]
2026-09-28  9:53 ` [PATCH v2] " Ciara Loftus
2026-09-29 10:25   ` Bruce Richardson

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