Re: iommu/vt-d: Cure VF irqdomain hickup

[Jason Gunthorpe]

On Thu, Nov 12, 2020 at 08:15:02PM +0100, Thomas Gleixner wrote:
> The recent changes to store the MSI irqdomain pointer in struct device
> missed that Intel DMAR does not register virtual function devices.  Due to
> that a VF device gets the plain PCI-MSI domain assigned and then issues
> compat MSI messages which get caught by the interrupt remapping unit.
> 
> Cure that by inheriting the irq domain from the physical function
> device.
> 
> That's a temporary workaround. The correct fix is to inherit the irq domain
> from the bus, but that's a larger effort which needs quite some other
> changes to the way how x86 manages PCI and MSI domains.
> 
> Fixes: 85a8dfc57a0b ("iommm/vt-d: Store irq domain in struct device")
> Reported-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
> Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> ---
>  drivers/iommu/intel/dmar.c |   19 ++++++++++++++++++-
>  1 file changed, 18 insertions(+), 1 deletion(-)

Our QA says it solves the issue:

Tested-by: Itay Aveksis <itayav@xxxxxxxxxx>

Thanks,
Jason