From: Lu Baolu <baolu.lu@linux.intel.com>
To: Janusz Krzysztofik <janusz.krzysztofik@linux.intel.com>
Cc: linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org,
"Michał Wajdeczko" <michal.wajdeczko@intel.com>,
"David Woodhouse" <dwmw2@infradead.org>,
intel-gfx@lists.freedesktop.org
Subject: Re: [RFC PATCH] iommu/vt-d: Fix IOMMU field not populated on device hot re-plug
Date: Thu, 29 Aug 2019 09:43:31 +0800 [thread overview]
Message-ID: <0cf4e930-1132-1e7f-815b-57a08a1fe5de@linux.intel.com> (raw)
In-Reply-To: <3275480.HMaYE7B3nd@jkrzyszt-desk.ger.corp.intel.com>
Hi Janusz,
On 8/28/19 10:17 PM, Janusz Krzysztofik wrote:
>> We should avoid kernel panic when a intel_unmap() is called against
>> a non-existent domain.
> Does that mean you suggest to replace
> BUG_ON(!domain);
> with something like
> if (WARN_ON(!domain))
> return;
> and to not care of orphaned mappings left allocated? Is there a way to inform
> users that their active DMA mappings are no longer valid and they shouldn't
> call dma_unmap_*()?
>
>> But we shouldn't expect the IOMMU driver not
>> cleaning up the domain info when a device remove notification comes and
>> wait until all file descriptors being closed, right?
> Shouldn't then the IOMMU driver take care of cleaning up resources still
> allocated on device remove before it invalidates and forgets their pointers?
>
You are right. We need to wait until all allocated resources (iova and
mappings) to be released.
How about registering a callback for BUS_NOTIFY_UNBOUND_DRIVER, and
removing the domain info when the driver detachment completes?
> Thanks,
> Janusz
Best regards,
Baolu
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next prev parent reply other threads:[~2019-08-29 1:45 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-22 14:29 [RFC PATCH] iommu/vt-d: Fix IOMMU field not populated on device hot re-plug Janusz Krzysztofik
2019-08-23 1:51 ` Lu Baolu
2019-08-26 8:15 ` Janusz Krzysztofik
2019-08-26 8:29 ` Lu Baolu
2019-08-27 9:35 ` Janusz Krzysztofik
2019-08-28 0:56 ` Lu Baolu
2019-08-28 14:17 ` Janusz Krzysztofik
2019-08-29 1:43 ` Lu Baolu [this message]
2019-08-29 7:58 ` Janusz Krzysztofik
2019-08-29 9:08 ` Lu Baolu
2019-09-02 8:37 ` Janusz Krzysztofik
2019-09-03 1:29 ` Lu Baolu
2019-09-03 7:41 ` Janusz Krzysztofik
2019-10-01 15:01 ` Janusz Krzysztofik
2019-10-08 2:27 ` Lu Baolu
2019-10-11 6:54 ` Lu Baolu
2019-10-11 10:27 ` Janusz Krzysztofik
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