Re: [PATCH v2] x86/CPUID: unconditionally set XEN_HVM_CPUID_IOMMU_MAPPINGS

[Jan Beulich <jbeulich@xxxxxxxx>]

On 19.01.2021 14:07, Roger Pau Monne wrote:
> This is a revert of f5cfa0985673 plus a rework of the comment that
> accompanies the setting of the flag so we don't forget why it needs to
> be unconditionally set: it's indicating whether the version of Xen has
> the original issue fixed and IOMMU entries are created for
> grant/foreign maps.
> 
> If the flag is only exposed when the IOMMU is enabled the guest could
> resort to use bounce buffers when running backends as it would assume
> the underlying Xen version still has the bug present and thus
> grant/foreign maps cannot be used with devices.
> 
> Signed-off-by: Roger Pau Monné <roger.pau@xxxxxxxxxx>

Acked-by: Jan Beulich <jbeulich@xxxxxxxx>

This time for real, I suppose.

Jan