> From: Auger Eric <[email protected]> > Sent: Thursday, August 13, 2020 5:31 PM > > Hi Yi, > > On 8/13/20 11:25 AM, Liu, Yi L wrote: > > Hi Eric, > > > > > >> From: Auger Eric <[email protected]> > >> Sent: Thursday, August 13, 2020 5:12 PM > >> > >> Hi Jacob, > >> > >> On 7/30/20 2:21 AM, Jacob Pan wrote: > >>> IOMMU user APIs are responsible for processing user data. This patch > >>> changes the interface such that user pointers can be passed into > >>> IOMMU code directly. Separate kernel APIs without user pointers are > >>> introduced for in-kernel users of the UAPI functionality. > >> This is just done for a single function, ie. iommu_sva_unbind_gpasid. > >> > >> If I am not wrong there is no user of this latter after applying the > >> whole series? If correct you may remove it at this stage? > > > > the user of this function is in vfio. And it is the same with > > iommu_uapi_sva_bind/unbind_gpasid() and iommu_uapi_cache_invalidate(). > > > > https://lore.kernel.org/kvm/1595917664-33276-11-git-send-email-yi.l.li > > [email protected]/ > > https://lore.kernel.org/kvm/1595917664-33276-12-git-send-email-yi.l.li > > [email protected]/ > Yep I know ;-) But this series mostly deals with iommu uapi rework. > That's not a big deal though.
I see. btw. it's great if you can take a look on vfio v6 to see if your comments are well addressed. :-) Regards, Yi Liu > Thanks > > Eric > > > > Regards, > > Yi Liu > > > >>> > >>> IOMMU UAPI data has a user filled argsz field which indicates the > >>> data length of the structure. User data is not trusted, argsz must > >>> be validated based on the current kernel data size, mandatory data > >>> size, and feature flags. > >>> > >>> User data may also be extended, resulting in possible argsz increase. > >>> Backward compatibility is ensured based on size and flags (or the > >>> functional equivalent fields) checking. > >>> > >>> This patch adds sanity checks in the IOMMU layer. In addition to > >>> argsz, reserved/unused fields in padding, flags, and version are also > >>> checked. > >>> Details are documented in Documentation/userspace-api/iommu.rst > >>> > >>> Signed-off-by: Liu Yi L <[email protected]> > >>> Signed-off-by: Jacob Pan <[email protected]> > >>> --- > >>> drivers/iommu/iommu.c | 201 > >> ++++++++++++++++++++++++++++++++++++++++++++++++-- > >>> include/linux/iommu.h | 28 ++++--- > >>> 2 files changed, 212 insertions(+), 17 deletions(-) > >>> > >>> diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index > >>> 3a913ce94a3d..1ee55c4b3a3a 100644 > >>> --- a/drivers/iommu/iommu.c > >>> +++ b/drivers/iommu/iommu.c > >>> @@ -1950,33 +1950,218 @@ int iommu_attach_device(struct iommu_domain > >> *domain, struct device *dev) > >>> } > >>> EXPORT_SYMBOL_GPL(iommu_attach_device); > >>> > >>> +/* > >>> + * Check flags and other user provided data for valid combinations. > >>> +We also > >>> + * make sure no reserved fields or unused flags are set. This is to > >>> +ensure > >>> + * not breaking userspace in the future when these fields or flags are > >>> used. > >>> + */ > >>> +static int iommu_check_cache_invl_data(struct > >>> +iommu_cache_invalidate_info > >> *info) > >>> +{ > >>> + u32 mask; > >>> + int i; > >>> + > >>> + if (info->version != IOMMU_CACHE_INVALIDATE_INFO_VERSION_1) > >>> + return -EINVAL; > >>> + > >>> + mask = (1 << IOMMU_CACHE_INV_TYPE_NR) - 1; > >>> + if (info->cache & ~mask) > >>> + return -EINVAL; > >>> + > >>> + if (info->granularity >= IOMMU_INV_GRANU_NR) > >>> + return -EINVAL; > >>> + > >>> + switch (info->granularity) { > >>> + case IOMMU_INV_GRANU_ADDR: > >>> + if (info->cache & IOMMU_CACHE_INV_TYPE_PASID) > >>> + return -EINVAL; > >>> + > >>> + mask = IOMMU_INV_ADDR_FLAGS_PASID | > >>> + IOMMU_INV_ADDR_FLAGS_ARCHID | > >>> + IOMMU_INV_ADDR_FLAGS_LEAF; > >>> + > >>> + if (info->granu.addr_info.flags & ~mask) > >>> + return -EINVAL; > >>> + break; > >>> + case IOMMU_INV_GRANU_PASID: > >>> + mask = IOMMU_INV_PASID_FLAGS_PASID | > >>> + IOMMU_INV_PASID_FLAGS_ARCHID; > >>> + if (info->granu.pasid_info.flags & ~mask) > >>> + return -EINVAL; > >>> + > >>> + break; > >>> + case IOMMU_INV_GRANU_DOMAIN: > >>> + if (info->cache & IOMMU_CACHE_INV_TYPE_DEV_IOTLB) > >>> + return -EINVAL; > >>> + break; > >>> + default: > >>> + return -EINVAL; > >>> + } > >>> + > >>> + /* Check reserved padding fields */ > >>> + for (i = 0; i < sizeof(info->padding); i++) { > >>> + if (info->padding[i]) > >>> + return -EINVAL; > >>> + } > >>> + > >>> + return 0; > >>> +} > >>> + > >>> int iommu_uapi_cache_invalidate(struct iommu_domain *domain, struct > >>> device > >> *dev, > >>> - struct iommu_cache_invalidate_info *inv_info) > >>> + void __user *uinfo) > >>> { > >>> + struct iommu_cache_invalidate_info inv_info = { 0 }; > >>> + u32 minsz; > >>> + int ret = 0; > >>> + > >>> if (unlikely(!domain->ops->cache_invalidate)) > >>> return -ENODEV; > >>> > - return domain->ops->cache_invalidate(domain, dev, inv_info); > >>> + /* > >>> + * No new spaces can be added before the variable sized union, the > >>> + * minimum size is the offset to the union. > >>> + */ > >>> + minsz = offsetof(struct iommu_cache_invalidate_info, granu); > >>> + > >>> + /* Copy minsz from user to get flags and argsz */ > >>> + if (copy_from_user(&inv_info, uinfo, minsz)) > >>> + return -EFAULT; > >>> + > >>> + /* Fields before variable size union is mandatory */ > >>> + if (inv_info.argsz < minsz) > >>> + return -EINVAL; > >>> + > >>> + /* PASID and address granu require additional info beyond minsz */ > >>> + if (inv_info.argsz == minsz && > >>> + ((inv_info.granularity == IOMMU_INV_GRANU_PASID) || > >>> + (inv_info.granularity == IOMMU_INV_GRANU_ADDR))) > >>> + return -EINVAL; > >>> + > >>> + if (inv_info.granularity == IOMMU_INV_GRANU_PASID && > >>> + inv_info.argsz < offsetofend(struct > >>> +iommu_cache_invalidate_info, > >> granu.pasid_info)) > >>> + return -EINVAL; > >>> + > >>> + if (inv_info.granularity == IOMMU_INV_GRANU_ADDR && > >>> + inv_info.argsz < offsetofend(struct > >>> +iommu_cache_invalidate_info, > >> granu.addr_info)) > >>> + 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 *)&inv_info + minsz, uinfo + minsz, > >>> + min_t(u32, inv_info.argsz, sizeof(inv_info)) - > >>> minsz)) > >>> + return -EFAULT; > >>> + > >>> + /* Now the argsz is validated, check the content */ > >>> + ret = iommu_check_cache_invl_data(&inv_info); > >>> + if (ret) > >>> + return ret; > >>> + > >>> + return domain->ops->cache_invalidate(domain, dev, &inv_info); > >>> } > >>> EXPORT_SYMBOL_GPL(iommu_uapi_cache_invalidate); > >>> > >>> -int iommu_uapi_sva_bind_gpasid(struct iommu_domain *domain, > >>> - struct device *dev, struct iommu_gpasid_bind_data > >> *data) > >>> +static int iommu_check_bind_data(struct iommu_gpasid_bind_data > >>> +*data) { > >>> + u32 mask; > >>> + int i; > >>> + > >>> + if (data->version != IOMMU_GPASID_BIND_VERSION_1) > >>> + return -EINVAL; > >>> + > >>> + /* Check the range of supported formats */ > >>> + if (data->format >= IOMMU_PASID_FORMAT_LAST) > >>> + return -EINVAL; > >>> + > >>> + /* Check all flags */ > >>> + mask = IOMMU_SVA_GPASID_VAL; > >>> + if (data->flags & ~mask) > >>> + return -EINVAL; > >>> + > >>> + /* Check reserved padding fields */ > >>> + for (i = 0; i < sizeof(data->padding); i++) { > >>> + if (data->padding[i]) > >>> + return -EINVAL; > >>> + } > >>> + > >>> + return 0; > >>> +} > >>> + > >>> +static int iommu_sva_prepare_bind_data(void __user *udata, > >>> + struct iommu_gpasid_bind_data *data) > >>> { > >>> + u32 minsz; > >>> + > >>> + /* > >>> + * No new spaces can be added before the variable sized union, the > >>> + * minimum size is the offset to the union. > >>> + */ > >>> + minsz = offsetof(struct iommu_gpasid_bind_data, vendor); > >>> + > >>> + /* Copy minsz from user to get flags and argsz */ > >>> + if (copy_from_user(data, udata, minsz)) > >>> + return -EFAULT; > >>> + > >>> + /* Fields before variable size union is mandatory */ > >>> + if (data->argsz < minsz) > >>> + return -EINVAL; > >>> + /* > >>> + * User might be using a newer UAPI header, we shall let IOMMU vendor > >>> + * driver decide on what size it needs. Since the guest PASID bind data > >>> + * can be vendor specific, larger argsz could be the result of extension > >>> + * for one vendor but it should not affect another vendor. > >>> + * Copy the remaining user data _after_ minsz > >>> + */ > >>> + if (copy_from_user((void *)data + minsz, udata + minsz, > >>> + min_t(u32, data->argsz, sizeof(*data)) - minsz)) > >>> + return -EFAULT; > >>> + > >>> + return iommu_check_bind_data(data); } > >>> + > >>> +int iommu_uapi_sva_bind_gpasid(struct iommu_domain *domain, struct > >>> +device > >> *dev, > >>> + void __user *udata) > >>> +{ > >>> + struct iommu_gpasid_bind_data data = { 0 }; > >>> + int ret; > >>> + > >>> if (unlikely(!domain->ops->sva_bind_gpasid)) > >>> return -ENODEV; > >>> > >>> - return domain->ops->sva_bind_gpasid(domain, dev, data); > >>> + ret = iommu_sva_prepare_bind_data(udata, &data); > >>> + if (ret) > >>> + return ret; > >>> + > >>> + return domain->ops->sva_bind_gpasid(domain, dev, &data); > >>> } > >>> EXPORT_SYMBOL_GPL(iommu_uapi_sva_bind_gpasid); > >>> > >>> -int iommu_uapi_sva_unbind_gpasid(struct iommu_domain *domain, > >>> struct device > >> *dev, > >>> - ioasid_t pasid) > >>> +int iommu_sva_unbind_gpasid(struct iommu_domain *domain, struct device > *dev, > >>> + struct iommu_gpasid_bind_data *data) > >>> { > >>> if (unlikely(!domain->ops->sva_unbind_gpasid)) > >>> return -ENODEV; > >>> > >>> - return domain->ops->sva_unbind_gpasid(dev, pasid); > >>> + return domain->ops->sva_unbind_gpasid(dev, data->hpasid); } > >>> +EXPORT_SYMBOL_GPL(iommu_sva_unbind_gpasid); > >>> + > >>> +int iommu_uapi_sva_unbind_gpasid(struct iommu_domain *domain, > >>> +struct device > >> *dev, > >>> + void __user *udata) > >>> +{ > >>> + struct iommu_gpasid_bind_data data = { 0 }; > >>> + int ret; > >>> + > >>> + if (unlikely(!domain->ops->sva_bind_gpasid)) > >>> + return -ENODEV; > >>> + > >>> + ret = iommu_sva_prepare_bind_data(udata, &data); > >>> + if (ret) > >>> + return ret; > >>> + > >>> + return iommu_sva_unbind_gpasid(domain, dev, &data); > >>> } > >>> EXPORT_SYMBOL_GPL(iommu_uapi_sva_unbind_gpasid); > >>> > >>> diff --git a/include/linux/iommu.h b/include/linux/iommu.h index > >>> 2dcc1a33f6dc..4a02c9e09048 100644 > >>> --- a/include/linux/iommu.h > >>> +++ b/include/linux/iommu.h > >>> @@ -432,11 +432,14 @@ extern void iommu_detach_device(struct > >> iommu_domain *domain, > >>> struct device *dev); > >>> extern int iommu_uapi_cache_invalidate(struct iommu_domain *domain, > >>> struct device *dev, > >>> - struct iommu_cache_invalidate_info > >>> *inv_info); > >>> + void __user *uinfo); > >>> + > >>> extern int iommu_uapi_sva_bind_gpasid(struct iommu_domain *domain, > >>> - struct device *dev, struct > >> iommu_gpasid_bind_data *data); > >>> + struct device *dev, void __user *udata); > >>> extern int iommu_uapi_sva_unbind_gpasid(struct iommu_domain *domain, > >>> - struct device *dev, ioasid_t pasid); > >>> + struct device *dev, void __user *udata); > extern int > >>> +iommu_sva_unbind_gpasid(struct iommu_domain *domain, > >>> + struct device *dev, struct > >> iommu_gpasid_bind_data *data); > >>> 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, @@ -1054,22 +1057,29 @@ static inline int > >>> iommu_sva_get_pasid(struct > >> iommu_sva *handle) > >>> return IOMMU_PASID_INVALID; > >>> } > >>> > >>> -static inline int iommu_uapi_cache_invalidate(struct iommu_domain > >>> *domain, > >>> - struct device *dev, > >>> - struct iommu_cache_invalidate_info > >> *inv_info) > >>> +static inline int > >>> +iommu_uapi_cache_invalidate(struct iommu_domain *domain, > >>> + struct device *dev, > >>> + struct iommu_cache_invalidate_info *inv_info) > >>> { > >>> return -ENODEV; > >>> } > >>> > >>> static inline int iommu_uapi_sva_bind_gpasid(struct iommu_domain *domain, > >>> - struct device *dev, > >>> - struct iommu_gpasid_bind_data > >>> *data) > >>> + struct device *dev, void __user > >>> *udata) > >>> { > >>> return -ENODEV; > >>> } > >>> > >>> static inline int iommu_uapi_sva_unbind_gpasid(struct iommu_domain > >>> *domain, > >>> - struct device *dev, int pasid) > >>> + struct device *dev, void __user > >>> *udata) > { > >>> + return -ENODEV; > >>> +} > >>> + > >>> +static inline int iommu_sva_unbind_gpasid(struct iommu_domain *domain, > >>> + struct device *dev, > >>> + struct iommu_gpasid_bind_data *data) > >>> { > >>> return -ENODEV; > >>> } > >>> > >> Otherwise looks good to me > >> Reviewed-by: Eric Auger <[email protected]> > >> > >> Thanks > >> > >> Eric > >
