On Fri, 2024-10-18 at 10:08 +0200, Roger Pau Monne wrote:
> When using AMD-VI interrupt remapping the vector field in the IO-APIC RTE is
> repurposed to contain part of the offset into the remapping table. Previous
> to
> 2ca9fbd739b8 Xen had logic so that the offset into the interrupt remapping
> table would match the vector. Such logic was mandatory for end of interrupt
> to
> work, since the vector field (even when not containing a vector) is used by
> the
> IO-APIC to find for which pin the EOI must be performed.
>
> Introduce a table to store the EOI handlers when using interrupt remapping, so
> that the IO-APIC driver can translate pins into EOI handlers without having to
> read the IO-APIC RTE entry. Note that to simplify the logic such table is
> used
> unconditionally when interrupt remapping is enabled, even if strictly it would
> only be required for AMD-Vi.
>
> Reported-by: Willi Junga <xenproj...@ymy.be>
> Suggested-by: David Woodhouse <d...@amazon.co.uk>
> Fixes: 2ca9fbd739b8 ('AMD IOMMU: allocate IRTE entries instead of using a
> static mapping')
> Signed-off-by: Roger Pau Monné <roger....@citrix.com>Hm, couldn't we just have used the pin#? The AMD IOMMU has per-device IRTE, so you *know* you can just use IRTE indices 0-23 for the I/O APIC pins.
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