Re: [PATCH v2 1/2] PCI: vmd: Assign VMD IRQ domain before enumeration

["Patel, Nirmal" <nirmal.patel@linux.intel.com>]

On 3/16/2022 8:51 AM, Nirmal Patel wrote:
> From: Nirmal Patel <nirmal.patel@linux.intel.com>
>
> VMD creates and assigns a separate IRQ domain only when MSI remapping is
> enabled. For example VMD-MSI. But VMD doesn't assign IRQ domain when
> MSI remapping is disabled resulting child devices getting default
> PCI-MSI IRQ domain. Now when interrupt remapping is enabled by
> intel-iommu all the PCI devices are assigned INTEL-IR-MSI domain
> including VMD endpoints. But devices behind VMD get PCI-MSI IRQ domain
> when VMD create a root bus and configures child devices.
>
> As a result DMAR errors were observed when interrupt remapping was
> enabled on Intel Icelake CPUs. For instance:
>
>   DMAR: DRHD: handling fault status reg 2
>   DMAR: [INTR-REMAP] Request device [0xe2:0x00.0] fault index 0xa00 [fault reason 0x25] Blocked a compatibility format interrupt request
>
> Acked-by: Dan Williams <dan.j.williams@intel.com>
> Signed-off-by: Nirmal Patel <nirmal.patel@linux.intel.com>
> ---
>  drivers/pci/controller/vmd.c | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/drivers/pci/controller/vmd.c b/drivers/pci/controller/vmd.c
> index cc166c683638..3a6570e5b765 100644
> --- a/drivers/pci/controller/vmd.c
> +++ b/drivers/pci/controller/vmd.c
> @@ -853,6 +853,8 @@ static int vmd_enable_domain(struct vmd_dev *vmd, unsigned long features)
>  	vmd_attach_resources(vmd);
>  	if (vmd->irq_domain)
>  		dev_set_msi_domain(&vmd->bus->dev, vmd->irq_domain);
> +	else
> +		dev_set_msi_domain(&vmd->bus->dev, dev_get_msi_domain(&vmd->dev->dev));
>  
>  	vmd_acpi_begin();
>  

Gentle ping!

Thanks
nirmal