On Thu, Jun 04, 2020 at 11:19:44AM +0200, Joerg Roedel wrote:
> From: Joerg Roedel <[email protected]>
>
> The iommu_group_do_dma_attach() must not attach devices which have
> deferred_attach set. Otherwise devices could cause IOMMU faults when
> re-initialized in a kdump kernel.
>
> Fixes: deac0b3bed26 ("iommu: Split off default domain allocation from group
> assignment")
> Reported-by: Jerry Snitselaar <[email protected]>
> Reviewed-by: Jerry Snitselaar <[email protected]>
> Tested-by: Jerry Snitselaar <[email protected]>
> Signed-off-by: Joerg Roedel <[email protected]>
> ---
> drivers/iommu/iommu.c | 6 +++++-
> 1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
> index b5ea203f6c68..5a6d509f72b6 100644
> --- a/drivers/iommu/iommu.c
> +++ b/drivers/iommu/iommu.c
> @@ -1680,8 +1680,12 @@ static void probe_alloc_default_domain(struct bus_type
> *bus,
> static int iommu_group_do_dma_attach(struct device *dev, void *data)
> {
> struct iommu_domain *domain = data;
> + int ret = 0;
>
> - return __iommu_attach_device(domain, dev);
> + if (!iommu_is_attach_deferred(group->domain, dev))
> + ret = __iommu_attach_device(group->domain, dev);
And of course with the same bug as my original diff. Fixed that up
before applying it. (group->domain -> domain).
Joerg
