On Thu, May 18, 2023 at 05:43:51AM +0000, Vasant Hegde wrote:
> IOMMU v2 page table supports 4 level (47 bit) or 5 level (56 bit) virtual
> address space. Current code assumes it can support 64bit IOVA address
> space. If IOVA allocator allocates virtual address > 47/56 bit (depending
> on page table level) then it will do wrong mapping and cause invalid
> translation.
>
> Hence adjust aperture size to use max address supported by the page table.
>
> Reported-by: Jerry Snitselaar <jsnitsel@xxxxxxxxxx>
> Fixes: aaac38f61487 ("iommu/amd: Initial support for AMD IOMMU v2 page table")
> Cc: <Stable@xxxxxxxxxxxxxxx> # v6.0+
> Cc: Suravee Suthikulpanit <suravee.suthikulpanit@xxxxxxx>
> Signed-off-by: Vasant Hegde <vasant.hegde@xxxxxxx>
> ---
> drivers/iommu/amd/iommu.c | 11 ++++++++++-
> 1 file changed, 10 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c
> index 5aaa4cf84506..e14c7c666745 100644
> --- a/drivers/iommu/amd/iommu.c
> +++ b/drivers/iommu/amd/iommu.c
> @@ -2128,6 +2128,15 @@ static struct protection_domain *protection_domain_alloc(unsigned int type)
> return NULL;
> }
>
> +static inline u64 dma_max_address(void)
> +{
> + if (amd_iommu_pgtable == AMD_IOMMU_V1)
> + return ~0ULL;
> +
> + /* V2 with 4/5 level page table */
> + return ((1ULL << PM_LEVEL_SHIFT(amd_iommu_gpt_level)) - 1);
Hi Vasant,
For the stable releases, this will need to be PAGE_MODE_4_LEVEL
instead of amd_iommu_gpt_level? The 6.4 merge window is when
amd_iommu_gpt_level arrived with the 5 level page table changes.
Regards,
Jerry
> +}
> +
> static struct iommu_domain *amd_iommu_domain_alloc(unsigned type)
> {
> struct protection_domain *domain;
> @@ -2144,7 +2153,7 @@ static struct iommu_domain *amd_iommu_domain_alloc(unsigned type)
> return NULL;
>
> domain->domain.geometry.aperture_start = 0;
> - domain->domain.geometry.aperture_end = ~0ULL;
> + domain->domain.geometry.aperture_end = dma_max_address();
> domain->domain.geometry.force_aperture = true;
>
> return &domain->domain;
> --
> 2.31.1
>
