Re: [PATCH v3] irq_remap: disable IRQ remapping if any IOAPIC lacks an IOMMU

[Joerg Roedel <joerg.roedel@amd.com>]

On Wed, Aug 08, 2012 at 08:27:03AM -0500, Seth Forshee wrote:
> The ACPI tables in the Macbook Air 5,1 define a single IOAPIC with id 2,
> but the only remapping unit described in the DMAR table matches id 0.
> Interrupt remapping fails as a result, and the kernel panics with the
> message "timer doesn't work through Interrupt-remapped IO-APIC."
> 
> To fix this, check each IOAPIC for a corresponding IOMMU. If an IOMMU is
> not found, do not allow IRQ remapping to be enabled.
> 
> v2: Move check to parse_ioapics_under_ir(), raise log level to KERN_ERR,
>     and add FW_BUG to the log message
> v3: Skip check if IOMMU doesn't support interrupt remapping and remove
>     existing check that the IOMMU count equals the IOAPIC count
> 
> Acked-by: Suresh Siddha <suresh.b.siddha@intel.com>
> Signed-off-by: Seth Forshee <seth.forshee@canonical.com>
> ---
>  drivers/iommu/intel_irq_remapping.c |   18 +++++++++++++-----
>  1 file changed, 13 insertions(+), 5 deletions(-)

Applied to iommu/fixes, thanks.