Hi Jacob, On 11/18/20 5:19 PM, Jacob Pan wrote: > Hi Eric, > > On Wed, 18 Nov 2020 12:21:37 +0100, Eric Auger <eric.au...@redhat.com> > wrote: > >> In virtualization use case, when a guest is assigned >> a PCI host device, protected by a virtual IOMMU on the guest, >> the physical IOMMU must be programmed to be consistent with >> the guest mappings. If the physical IOMMU supports two >> translation stages it makes sense to program guest mappings >> onto the first stage/level (ARM/Intel terminology) while the host >> owns the stage/level 2. >> >> In that case, it is mandated to trap on guest configuration >> settings and pass those to the physical iommu driver. >> >> This patch adds a new API to the iommu subsystem that allows >> to set/unset the pasid table information. >> >> A generic iommu_pasid_table_config struct is introduced in >> a new iommu.h uapi header. This is going to be used by the VFIO >> user API. >> >> Signed-off-by: Jean-Philippe Brucker <jean-philippe.bruc...@arm.com> >> Signed-off-by: Liu, Yi L <yi.l....@linux.intel.com> >> Signed-off-by: Ashok Raj <ashok....@intel.com> >> Signed-off-by: Jacob Pan <jacob.jun....@linux.intel.com> >> Signed-off-by: Eric Auger <eric.au...@redhat.com> >> >> --- >> >> v12 -> v13: >> - Fix config check >> >> v11 -> v12: >> - add argsz, name the union >> --- >> drivers/iommu/iommu.c | 68 ++++++++++++++++++++++++++++++++++++++ >> include/linux/iommu.h | 21 ++++++++++++ >> include/uapi/linux/iommu.h | 54 ++++++++++++++++++++++++++++++ >> 3 files changed, 143 insertions(+) >> >> diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c >> index b53446bb8c6b..978fe34378fb 100644 >> --- a/drivers/iommu/iommu.c >> +++ b/drivers/iommu/iommu.c >> @@ -2171,6 +2171,74 @@ int iommu_uapi_sva_unbind_gpasid(struct >> iommu_domain *domain, struct device *dev } >> EXPORT_SYMBOL_GPL(iommu_uapi_sva_unbind_gpasid); >> >> +int iommu_attach_pasid_table(struct iommu_domain *domain, >> + struct iommu_pasid_table_config *cfg) >> +{ >> + if (unlikely(!domain->ops->attach_pasid_table)) >> + return -ENODEV; >> + >> + return domain->ops->attach_pasid_table(domain, cfg); >> +} >> + >> +int iommu_uapi_attach_pasid_table(struct iommu_domain *domain, >> + void __user *uinfo) >> +{ >> + struct iommu_pasid_table_config pasid_table_data = { 0 }; >> + u32 minsz; >> + >> + if (unlikely(!domain->ops->attach_pasid_table)) >> + return -ENODEV; >> + >> + /* >> + * No new spaces can be added before the variable sized union, >> the >> + * minimum size is the offset to the union. >> + */ >> + minsz = offsetof(struct iommu_pasid_table_config, vendor_data); >> + >> + /* Copy minsz from user to get flags and argsz */ >> + if (copy_from_user(&pasid_table_data, uinfo, minsz)) >> + return -EFAULT; >> + >> + /* Fields before the variable size union are mandatory */ >> + if (pasid_table_data.argsz < minsz) >> + return -EINVAL; >> + >> + /* PASID and address granu require additional info beyond minsz >> */ >> + if (pasid_table_data.version != PASID_TABLE_CFG_VERSION_1) >> + return -EINVAL; >> + if (pasid_table_data.format == IOMMU_PASID_FORMAT_SMMUV3 && >> + pasid_table_data.argsz < >> + offsetofend(struct iommu_pasid_table_config, >> vendor_data.smmuv3)) >> + return -EINVAL; >> + >> + /* >> + * User might be using a newer UAPI header which has a larger >> data >> + * size, we shall support the existing flags within the current >> + * size. Copy the remaining user data _after_ minsz but not more >> + * than the current kernel supported size. >> + */ >> + if (copy_from_user((void *)&pasid_table_data + minsz, uinfo + >> minsz, >> + min_t(u32, pasid_table_data.argsz, >> sizeof(pasid_table_data)) - minsz)) >> + return -EFAULT; >> + >> + /* Now the argsz is validated, check the content */ >> + if (pasid_table_data.config < IOMMU_PASID_CONFIG_TRANSLATE || >> + pasid_table_data.config > IOMMU_PASID_CONFIG_ABORT) >> + return -EINVAL; >> + >> + return domain->ops->attach_pasid_table(domain, >> &pasid_table_data); +} >> +EXPORT_SYMBOL_GPL(iommu_uapi_attach_pasid_table); >> + >> +void iommu_detach_pasid_table(struct iommu_domain *domain) >> +{ >> + if (unlikely(!domain->ops->detach_pasid_table)) >> + return; >> + >> + domain->ops->detach_pasid_table(domain); >> +} >> +EXPORT_SYMBOL_GPL(iommu_detach_pasid_table); >> + >> static void __iommu_detach_device(struct iommu_domain *domain, >> struct device *dev) >> { >> diff --git a/include/linux/iommu.h b/include/linux/iommu.h >> index b95a6f8db6ff..464fcbecf841 100644 >> --- a/include/linux/iommu.h >> +++ b/include/linux/iommu.h >> @@ -223,6 +223,8 @@ struct iommu_iotlb_gather { >> * @cache_invalidate: invalidate translation caches >> * @sva_bind_gpasid: bind guest pasid and mm >> * @sva_unbind_gpasid: unbind guest pasid and mm >> + * @attach_pasid_table: attach a pasid table >> + * @detach_pasid_table: detach the pasid table >> * @def_domain_type: device default domain type, return value: >> * - IOMMU_DOMAIN_IDENTITY: must use an identity domain >> * - IOMMU_DOMAIN_DMA: must use a dma domain >> @@ -287,6 +289,9 @@ struct iommu_ops { >> void *drvdata); >> void (*sva_unbind)(struct iommu_sva *handle); >> u32 (*sva_get_pasid)(struct iommu_sva *handle); >> + int (*attach_pasid_table)(struct iommu_domain *domain, >> + struct iommu_pasid_table_config *cfg); >> + void (*detach_pasid_table)(struct iommu_domain *domain); >> >> int (*page_response)(struct device *dev, >> struct iommu_fault_event *evt, >> @@ -434,6 +439,11 @@ extern int iommu_uapi_sva_unbind_gpasid(struct >> iommu_domain *domain, struct device *dev, void __user *udata); >> extern int iommu_sva_unbind_gpasid(struct iommu_domain *domain, >> struct device *dev, ioasid_t pasid); >> +extern int iommu_attach_pasid_table(struct iommu_domain *domain, >> + struct iommu_pasid_table_config >> *cfg); +extern int iommu_uapi_attach_pasid_table(struct iommu_domain >> *domain, >> + void __user *udata); >> +extern void iommu_detach_pasid_table(struct iommu_domain *domain); >> extern struct iommu_domain *iommu_get_domain_for_dev(struct device *dev); >> extern struct iommu_domain *iommu_get_dma_domain(struct device *dev); >> extern int iommu_map(struct iommu_domain *domain, unsigned long iova, >> @@ -639,6 +649,7 @@ struct iommu_sva *iommu_sva_bind_device(struct device >> *dev, void iommu_sva_unbind_device(struct iommu_sva *handle); >> u32 iommu_sva_get_pasid(struct iommu_sva *handle); >> >> + >> #else /* CONFIG_IOMMU_API */ >> >> struct iommu_ops {}; >> @@ -1020,6 +1031,16 @@ iommu_aux_get_pasid(struct iommu_domain *domain, >> struct device *dev) return -ENODEV; >> } >> >> +static inline >> +int iommu_attach_pasid_table(struct iommu_domain *domain, >> + struct iommu_pasid_table_config *cfg) >> +{ >> + return -ENODEV; >> +} >> + >> +static inline >> +void iommu_detach_pasid_table(struct iommu_domain *domain) {} >> + >> static inline struct iommu_sva * >> iommu_sva_bind_device(struct device *dev, struct mm_struct *mm, void >> *drvdata) { >> diff --git a/include/uapi/linux/iommu.h b/include/uapi/linux/iommu.h >> index e1d9e75f2c94..082d758dd016 100644 >> --- a/include/uapi/linux/iommu.h >> +++ b/include/uapi/linux/iommu.h >> @@ -338,4 +338,58 @@ struct iommu_gpasid_bind_data { >> } vendor; >> }; >> >> +/** >> + * struct iommu_pasid_smmuv3 - ARM SMMUv3 Stream Table Entry stage 1 >> related >> + * information >> + * @version: API version of this structure >> + * @s1fmt: STE s1fmt (format of the CD table: single CD, linear table >> + * or 2-level table) >> + * @s1dss: STE s1dss (specifies the behavior when @pasid_bits != 0 >> + * and no PASID is passed along with the incoming transaction) >> + * @padding: reserved for future use (should be zero) >> + * >> + * The PASID table is referred to as the Context Descriptor (CD) table >> on ARM >> + * SMMUv3. Please refer to the ARM SMMU 3.x spec (ARM IHI 0070A) for full >> + * details. >> + */ >> +struct iommu_pasid_smmuv3 { >> +#define PASID_TABLE_SMMUV3_CFG_VERSION_1 1 >> + __u32 version; >> + __u8 s1fmt; >> + __u8 s1dss; >> + __u8 padding[2]; >> +}; >> + >> +/** >> + * struct iommu_pasid_table_config - PASID table data used to bind guest >> PASID >> + * table to the host IOMMU >> + * @argsz: User filled size of this data >> + * @version: API version to prepare for future extensions >> + * @format: format of the PASID table >> + * @base_ptr: guest physical address of the PASID table >> + * @pasid_bits: number of PASID bits used in the PASID table >> + * @config: indicates whether the guest translation stage must >> + * be translated, bypassed or aborted. >> + * @padding: reserved for future use (should be zero) >> + * @vendor_data.smmuv3: table information when @format is >> + * %IOMMU_PASID_FORMAT_SMMUV3 >> + */ >> +struct iommu_pasid_table_config { >> + __u32 argsz; >> +#define PASID_TABLE_CFG_VERSION_1 1 >> + __u32 version; >> +#define IOMMU_PASID_FORMAT_SMMUV3 1 >> + __u32 format; > There will be a u32 gap here, right? perhaps another padding? Yes you're right (as per https://lists.cs.columbia.edu/pipermail/kvmarm/2019-January/034414.html). I will add some padding here and add some additional padding below.
Thanks Eric > >> + __u64 base_ptr; >> + __u8 pasid_bits; >> +#define IOMMU_PASID_CONFIG_TRANSLATE 1 >> +#define IOMMU_PASID_CONFIG_BYPASS 2 >> +#define IOMMU_PASID_CONFIG_ABORT 3 >> + __u8 config; >> + __u8 padding[2]; >> + union { >> + struct iommu_pasid_smmuv3 smmuv3; >> + } vendor_data; >> +}; >> + >> #endif /* _UAPI_IOMMU_H */ > > > Thanks, > > Jacob >