Hi Andre,
On 3/12/20 7:19 PM, Andre Przywara wrote:
> When we try to get an MSI cookie for a VFIO device, that can fail if
> CONFIG_IOMMU_DMA is not set. In this case iommu_get_msi_cookie() returns
> -ENODEV, and that should not be fatal.
>
> Ignore that case and proceed with the initialisation.
>
> This fixes VFIO with a platform device on the Calxeda Midway (no MSIs).
>
> Signed-off-by: Andre Przywara <andre.przywara@xxxxxxx>
Would you mind resending this as non RFC (+ R-b tags) so that it gets a
chance to be taken by Alex for 5.7
Thanks
Eric
> ---
> Hi,
>
> not sure this is the right fix, or we should rather check if the
> platform doesn't support MSIs at all (which doesn't seem to be easy
> to do).
> Or is this because arm-smmu.c always reserves an IOMMU_RESV_SW_MSI
> region?
>
> Also this seems to be long broken, actually since Eric introduced MSI
> support in 4.10-rc3, but at least since the initialisation order was
> fixed with f6810c15cf9.
>
> Grateful for any insight.
>
> Cheers,
> Andre
>
> drivers/vfio/vfio_iommu_type1.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
> index a177bf2c6683..467e217ef09a 100644
> --- a/drivers/vfio/vfio_iommu_type1.c
> +++ b/drivers/vfio/vfio_iommu_type1.c
> @@ -1786,7 +1786,7 @@ static int vfio_iommu_type1_attach_group(void *iommu_data,
>
> if (resv_msi) {
> ret = iommu_get_msi_cookie(domain->domain, resv_msi_base);
> - if (ret)
> + if (ret && ret != -ENODEV)
> goto out_detach;
> }
>
>
