Re: [PATCH v14 13/13] iommu/smmuv3: Accept configs with more than one context descriptor

Zenghui Yu
2021-03-30T09:24:13Z

Hi Eric,

On 2021/2/24 4:56, Eric Auger wrote:
> In preparation for vSVA, let's accept userspace provided configs
> with more than one CD. We check the max CD against the host iommu
> capability and also the format (linear versus 2 level).
>
> Signed-off-by: Eric Auger <eric.auger@redhat.com>
> Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
> ---
> drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 13 ++++++++-----
> 1 file changed, 8 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
> index 332d31c0680f..ab74a0289893 100644
> --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
> +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
> @@ -3038,14 +3038,17 @@ static int arm_smmu_attach_pasid_table(struct iommu_domain *domain,
> if (smmu_domain->s1_cfg.set)
> goto out;
>
> - /*
> - * we currently support a single CD so s1fmt and s1dss
> - * fields are also ignored
> - */
> - if (cfg->pasid_bits)
> + list_for_each_entry(master, &smmu_domain->devices, domain_head) {
> + if (cfg->pasid_bits > master->ssid_bits)
> + goto out;
> + }
> + if (cfg->vendor_data.smmuv3.s1fmt == STRTAB_STE_0_S1FMT_64K_L2 &&
> + !(smmu->features & ARM_SMMU_FEAT_2_LVL_CDTAB))
> goto out;
>
> smmu_domain->s1_cfg.cdcfg.cdtab_dma = cfg->base_ptr;
> + smmu_domain->s1_cfg.s1cdmax = cfg->pasid_bits;
> + smmu_domain->s1_cfg.s1fmt = cfg->vendor_data.smmuv3.s1fmt;

And what about the SIDSS field?