Re: [PATCH for-4.20 v3 5/5] x86/iommu: disable interrupts at shutdown

[Jan Beulich <jbeulich@xxxxxxxx>]

On 11.02.2025 12:02, Roger Pau Monne wrote:
> Add a new hook to inhibit interrupt generation by the IOMMU(s).  Note the
> hook is currently only implemented for x86 IOMMUs.  The purpose is to
> disable interrupt generation at shutdown so any kexec chained image finds
> the IOMMU(s) in a quiesced state.
> 
> It would also prevent "Receive accept error" being raised as a result of
> non-disabled interrupts targeting offline CPUs.
> 
> Note that the iommu_quiesce() call in nmi_shootdown_cpus() is still
> required even when there's a preceding iommu_crash_shutdown() call; the
> later can become a no-op depending on the setting of the "crash-disable"
> command line option.
> 
> Signed-off-by: Roger Pau Monné <roger.pau@xxxxxxxxxx>
> ---
> Changes since v1:
>  - New in this version.
>  - Expand commit message.
>  - Check if the hook is implemented before attempting to call it.

The latter two are changes since v2, though, aiui. In any event
Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx>

Jan