Messages in this thread | | | Date | Fri, 24 Mar 2023 10:50:34 -0700 | From | Nicolin Chen <> | Subject | Re: [PATCH v1 12/14] iommu/arm-smmu-v3: Support IOMMU_DOMAIN_NESTED type of allocations |
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On Fri, Mar 24, 2023 at 04:44:58PM +0100, Eric Auger wrote: > > @@ -2923,8 +2949,16 @@ arm_smmu_domain_alloc_user(struct device *dev, struct iommu_domain *parent, > > const struct iommu_hwpt_arm_smmuv3 *user_cfg = user_data; > > struct arm_smmu_master *master = dev_iommu_priv_get(dev); > > unsigned type = IOMMU_DOMAIN_UNMANAGED; > > + struct arm_smmu_domain *s2 = NULL; > > + > > + if (parent) { > > + if (parent->ops != arm_smmu_ops.default_domain_ops) > > + return NULL; > > + type = IOMMU_DOMAIN_NESTED; > > + s2 = to_smmu_domain(parent); > > + } > Please can you explain the (use) case where !parent. This creates an > unmanaged S1?
It creates an unmanaged type of a domain. The decision to mark it as an unmanaged S1 or an unmanaged S2 domain, is done in the finalise() function that it checks the S2 flag and set a stage accordingly.
I think that I could add a few lines of comments inline or at the top of the function to ease the readability.
Thanks Nicolin
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