On Thu, Oct 24, 2024 at 08:34:12AM -0700, Jerry Snitselaar wrote:
> Only the first device that is passed when the domain is set up will
> have its reserved regions reserved in the iova address space. So if
> there are other devices in the group with unique reserved regions,
> those regions will not get reserved in the iova address space. All of
> the ranges do get set up in the iopagetables via calls to
> iommu_create_device_direct_mappings for all devices in a group.
>
> In the case of vt-d system this resulted in messages like the following:
>
> [ 1632.693264] DMAR: ERROR: DMA PTE for vPFN 0xf1f7e already set (to f1f7e003 not 173025001)
>
> To make sure iova ranges are reserved for the reserved regions all of
> the devices, call iova_reserve_iommu_regions in iommu_dma_init_domain
> prior to exiting in the case where the domain is already initialized.
>
> Cc: Robin Murphy <robin.murphy@xxxxxxx>
> Cc: Joerg Roedel <joro@xxxxxxxxxx>
> Cc: Will Deacon <will@xxxxxxxxxx>
> Cc: linux-kernel@xxxxxxxxxxxxxxx
> Cc: stable@xxxxxxxxxxxxxxx
> Fixes: 7c1b058c8b5a ("iommu/dma: Handle IOMMU API reserved regions")
> Signed-off-by: Jerry Snitselaar <jsnitsel@xxxxxxxxxx>
> ---
> Robin: I wasn't positive if this is the correct solution, or if it should be
> done for the entire group at once.
>
> drivers/iommu/dma-iommu.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
> index 2a9fa0c8cc00..5fd3cccbb233 100644
> --- a/drivers/iommu/dma-iommu.c
> +++ b/drivers/iommu/dma-iommu.c
> @@ -707,7 +707,7 @@ static int iommu_dma_init_domain(struct iommu_domain *domain, struct device *dev
> goto done_unlock;
> }
>
> - ret = 0;
> + ret = iova_reserve_iommu_regions(dev, domain);
> goto done_unlock;
> }
>
> --
> 2.44.0
>
Robin,
Any thoughts on this patch? In the case where this originally popped
up it was likely a crap DMAR table in an HPE system with an ilo, as
the RMRR in question had a device in the list that as far as I could
tell didn't actually exist. The 2nd function of the sata controller
was in the list, but not the first, and the first function was the
device where the group/domain was initialized. With some debugging
code I could see it set up the ioptes for the 2nd function, but it
wasn't reserving the range of iovas.
Regards,
Jerry
