Re: [PATCH 2/2] xen/virtio: Fix potential deadlock when accessing xen_grant_dma_devices

[Juergen Gross]

On 05.10.22 19:48, Oleksandr Tyshchenko wrote:
> From: Oleksandr Tyshchenko <oleksandr_tyshchenko@xxxxxxxx>
>
> As find_xen_grant_dma_data() is called from both interrupt and process
> contexts, the access to xen_grant_dma_devices XArray must be protected
> by xa_lock_irqsave to avoid deadlock scenario.
> As XArray API doesn't provide xa_store_irqsave helper, call lockless
> __xa_store directly and guard it externally.
>
> Also move the storage of the XArray's entry to a separate helper.
>
> Signed-off-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@xxxxxxxx>
> Fixes: d6aca3504c7d ("xen/grant-dma-ops: Add option to restrict memory access under Xen")

Reviewed-by: Juergen Gross <jgross@xxxxxxxx>


Juergen

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