Re: [Xen-devel] [PATCH for-4.13 v3] passthrough: simplify locking and logging

[Igor Druzhinin <igor.druzhinin@xxxxxxxxxx>]

On 20/11/2019 15:49, Jürgen Groß wrote:
> On 15.11.19 19:59, Igor Druzhinin wrote:
>> From: Paul Durrant <pdurrant@xxxxxxxxxx>
>>
>> Dropping the pcidevs lock between calling device_assigned() and
>> assign_device() means that the latter has to do the same check as the
>> former for no obvious gain. Also, since long running operations under
>> pcidevs lock already drop the lock and return -ERESTART periodically
>> there
>> is little point in immediately failing an assignment operation with
>> -ERESTART just because the pcidevs lock could not be acquired (for the
>> second time, having already blocked on acquiring the lock in
>> device_assigned()).
>>
>> This patch instead acquires the lock once for assignment (or test assign)
>> operations directly in iommu_do_pci_domctl() and thus can remove the
>> duplicate domain ownership check in assign_device(). Whilst in the
>> neighbourhood, the patch also removes some debug logging from
>> assign_device() and deassign_device() and replaces it with proper error
>> logging, which allows error logging in iommu_do_pci_domctl() to be
>> removed.
>>
>> Signed-off-by: Paul Durrant <paul.durrant@xxxxxxxxxx>
>> Signed-off-by: Igor Druzhinin <igor.druzhinin@xxxxxxxxxx>
> 
> As the release is coming nearer I don't want to take "cosmetic" patches
> for 4.13 anymore.
> 

Understood, we will carry it with our local patches then.

Igor

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