Re: [patch RFC 20/38] PCI: vmd: Mark VMD irqdomain with DOMAIN_BUS_VMD_MSI

[Bjorn Helgaas]

On Fri, Aug 21, 2020 at 02:24:44AM +0200, Thomas Gleixner wrote:
> Devices on the VMD bus use their own MSI irq domain, but it is not
> distinguishable from regular PCI/MSI irq domains. This is required
> to exclude VMD devices from getting the irq domain pointer set by
> interrupt remapping.
> 
> Override the default bus token.
> 
> Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> Cc: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
> Cc: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx>
> Cc: Jonathan Derrick <jonathan.derrick@xxxxxxxxx>
> Cc: linux-pci@xxxxxxxxxxxxxxx

Acked-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>

> ---
>  drivers/pci/controller/vmd.c |    6 ++++++
>  1 file changed, 6 insertions(+)
> 
> --- a/drivers/pci/controller/vmd.c
> +++ b/drivers/pci/controller/vmd.c
> @@ -579,6 +579,12 @@ static int vmd_enable_domain(struct vmd_
>  		return -ENODEV;
>  	}
>  
> +	/*
> +	 * Override the irq domain bus token so the domain can be distinguished
> +	 * from a regular PCI/MSI domain.
> +	 */
> +	irq_domain_update_bus_token(vmd->irq_domain, DOMAIN_BUS_VMD_MSI);
> +
>  	pci_add_resource(&resources, &vmd->resources[0]);
>  	pci_add_resource_offset(&resources, &vmd->resources[1], offset[0]);
>  	pci_add_resource_offset(&resources, &vmd->resources[2], offset[1]);
>