Re: [PATCH 2/7] vfio/pci: Lock external INTx masking ops

From: Reinette Chatre
Date: Fri Mar 08 2024 - 15:46:16 EST


Hi Alex,

On 3/6/2024 1:14 PM, Alex Williamson wrote:
> Mask operations through config space changes to DisINTx may race INTx
> configuration changes via ioctl. Create wrappers that add locking for
> paths outside of the core interrupt code.
>
> In particular, irq_type is updated holding igate, therefore testing
> is_intx() requires holding igate. For example clearing DisINTx from
> config space can otherwise race changes of the interrupt configuration.
>
> This aligns interfaces which may trigger the INTx eventfd into two
> camps, one side serialized by igate and the other only enabled while
> INTx is configured. A subsequent patch introduces synchronization for
> the latter flows.
>
> Fixes: 89e1f7d4c66d ("vfio: Add PCI device driver")
> Reported-by: Reinette Chatre <reinette.chatre@xxxxxxxxx>
> Signed-off-by: Alex Williamson <alex.williamson@xxxxxxxxxx>
> ---

Thank you very much.

Reviewed-by: Reinette Chatre <reinette.chatre@xxxxxxxxx>

Reinette