Re: [PATCH v7 6/7] xen/arm: process pending vPCI map/unmap operations

["Durrant, Paul" <xadimgnik@xxxxxxxxx>]

On 23/11/2021 23:59, Oleksandr Andrushchenko wrote:
> From: Oleksandr Andrushchenko <oleksandr_andrushchenko@xxxxxxxx>
>
> vPCI may map and unmap PCI device memory (BARs) being passed through which
> may take a lot of time. For this those operations may be deferred to be
> performed later, so that they can be safely preempted.
>
> Currently this deferred processing is happening in common IOREQ code
> which doesn't seem to be the right place for x86 and is even more
> doubtful because IOREQ may not be enabled for Arm at all.
> So, for Arm the pending vPCI work may have no chance to be executed
> if the processing is left as is in the common IOREQ code only.
> For that reason make vPCI processing happen in arch specific code.
>
> Please be aware that there are a few outstanding TODOs affecting this
> code path, see xen/drivers/vpci/header.c:map_range and
> xen/drivers/vpci/header.c:vpci_process_pending.
>
> Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@xxxxxxxx>
> [x86 part]
> Acked-by: Jan Beulich <jbeulich@xxxxxxxx>
> Reviewed-by: Julien Grall <jgrall@xxxxxxxxxx>
Reviewed-by: Paul Durrant <paul@xxxxxxx>