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Add APIs that can be used to fetch the preserved state of a device and IOMMU. The APIs will only be used during shutdown and after liveupdate so no locking needed. Reviewed-by: Pranjal Shrivastava Signed-off-by: Samiullah Khawaja --- drivers/iommu/liveupdate.c | 125 +++++++++++++++++++++++++++++++ include/linux/iommu-liveupdate.h | 45 +++++++++++ 2 files changed, 170 insertions(+) diff --git a/drivers/iommu/liveupdate.c b/drivers/iommu/liveupdate.c index 5f92a023ea65..ff76a23d9583 100644 --- a/drivers/iommu/liveupdate.c +++ b/drivers/iommu/liveupdate.c @@ -49,6 +49,17 @@ #define iommu_max_objs_per_page(_array) \ ((PAGE_SIZE - sizeof(struct iommu_array_hdr_ser)) / sizeof((_array)->objects[0])) +#define iommu_liveupdate_for_each_obj(_arr, _obj, _idx) \ + for ((_idx) = 0, (_obj) = (_arr)->objects; \ + (_idx) < (_arr)->hdr.nr_objects; (_idx)++, (_obj)++) \ + if (((_obj)->hdr.flags & IOMMU_SER_FLAG_DELETED)) \ + continue; \ + else + +#define iommu_liveupdate_for_each_arr(_arr) \ + for (; (_arr); (_arr) = (_arr)->hdr.next_array_phys ? \ + phys_to_virt((_arr)->hdr.next_array_phys) : NULL) + struct iommu_flb_obj { struct mutex lock; struct iommu_flb_ser *ser; @@ -259,6 +270,120 @@ void iommu_liveupdate_unregister_flb(struct liveupdate_file_handler *handler) } EXPORT_SYMBOL(iommu_liveupdate_unregister_flb); +/* + * iommu_liveupdate_flb_get_incoming() - Helper function to get FLB state + * @flb_objp: Pointer to get the restored FLB object + * + * Return: 0 if FLB state found and restored, error if no data found + */ +static int iommu_liveupdate_flb_get_incoming(struct iommu_flb_obj **flb_objp) +{ + struct iommu_flb_obj *flb_obj; + int ret; + + ret = liveupdate_flb_get_incoming(&iommu_flb, (void **)flb_objp); + if (ret == -ENODATA || ret == -ENOENT || ret == -EOPNOTSUPP) + return ret; + + if (ret) + goto err_fatal; + + flb_obj = *flb_objp; + mutex_lock(&flb_obj->lock); + + /* + * FLB version mismatch is considered fatal for security reasons for + * now. + */ + if (flb_obj->ser->version != IOMMU_LUO_FLB_VERSION) + goto err_fatal; + + /* + * Array Phys of each type should be valid if the FLB was created for + * preservation. This is true even if no devices, iommus or domains were + * preserved. + */ + if (!flb_obj->ser->iommu_array_phys || + !flb_obj->ser->device_array_phys || + !flb_obj->ser->iommu_domain_array_phys) + goto err_fatal; + + mutex_unlock(&flb_obj->lock); + return 0; + +err_fatal: + panic("Failed to restore IOMMU Live Update FLB\n"); +} + +/** + * iommu_for_each_preserved_device() - Iterate on preserved devices + * @fn: Iterator function to call for each preserved device + * @arg: Argument to pass to iterator function + * + * Return: 0 on success, or an error. + */ +int iommu_for_each_preserved_device(iommu_preserved_device_iter_fn fn, + void *arg) +{ + struct iommu_device_array_ser *array; + struct iommu_device_ser *device_ser; + struct iommu_flb_obj *flb_obj; + int ret, idx; + + ret = iommu_liveupdate_flb_get_incoming(&flb_obj); + if (ret) + return ret; + + array = phys_to_virt(flb_obj->ser->device_array_phys); + iommu_liveupdate_for_each_arr(array) { + iommu_liveupdate_for_each_obj(array, device_ser, idx) { + ret = fn(device_ser, arg); + if (ret) + goto out; + } + } + +out: + liveupdate_flb_put_incoming(&iommu_flb); + return ret; +} +EXPORT_SYMBOL(iommu_for_each_preserved_device); + +/** + * iommu_get_preserved_data() - Get preserved data for an IOMMU HW + * @token: Token used to preserve this IOMMU HW + * @type: IOMMU type in preserved state + * + * Gets the preserved state of an IOMMU HW using token and the IOMMU type. + * + * Return: struct iommu_hw_ser on success, NULL if no preserved state found. + */ +struct iommu_hw_ser *iommu_get_preserved_data(u64 token, enum iommu_type_ser type) +{ + struct iommu_hw_ser *iommu_ser = NULL; + struct iommu_hw_array_ser *array; + struct iommu_flb_obj *flb_obj; + int ret, idx; + + ret = iommu_liveupdate_flb_get_incoming(&flb_obj); + if (ret) + return NULL; + + array = phys_to_virt(flb_obj->ser->iommu_array_phys); + iommu_liveupdate_for_each_arr(array) { + iommu_liveupdate_for_each_obj(array, iommu_ser, idx) { + if (iommu_ser->token == token && iommu_ser->type == type) + goto out; + } + } + + iommu_ser = NULL; +out: + liveupdate_flb_put_incoming(&iommu_flb); + return iommu_ser; +} +EXPORT_SYMBOL(iommu_get_preserved_data); + static int alloc_object_ser(void **curr_array_ptr, u64 max_objs) { struct iommu_array_hdr_ser *curr_array = *curr_array_ptr; diff --git a/include/linux/iommu-liveupdate.h b/include/linux/iommu-liveupdate.h index 536bea09d064..06f66cc8f526 100644 --- a/include/linux/iommu-liveupdate.h +++ b/include/linux/iommu-liveupdate.h @@ -13,6 +13,16 @@ #include #include +/** + * iommu_preserved_device_iter_fn - Callback for iterating preserved devices + * @ser: Pointer to serialized device state + * @arg: User-defined context argument + * + * Return: 0 to continue iteration, or a negative error code to abort. + */ +typedef int (*iommu_preserved_device_iter_fn)(struct iommu_device_ser *ser, + void *arg); + #ifdef CONFIG_IOMMU_LIVEUPDATE int iommu_liveupdate_register_flb(struct liveupdate_file_handler *handler); void iommu_liveupdate_unregister_flb(struct liveupdate_file_handler *handler); @@ -37,6 +47,26 @@ static inline void *dev_iommu_preserved_state(struct device *dev) return NULL; } +/** + * iommu_domain_restored_state() - Get restored state of an IOMMU domain + * @domain: Pointer to struct iommu_domain to get restored state of. + * + * Return: Pointer to restored state on success, NULL on error. + */ +static inline void *iommu_domain_restored_state(struct iommu_domain *domain) +{ + struct iommu_domain_ser *ser; + + ser = domain->preserved_state; + if (ser && (ser->hdr.flags & IOMMU_SER_FLAG_INCOMING)) + return ser; + + return NULL; +} + +int iommu_for_each_preserved_device(iommu_preserved_device_iter_fn fn, + void *arg); +struct iommu_hw_ser *iommu_get_preserved_data(u64 token, enum iommu_type_ser type); int iommu_preserve_domain(struct iommu_domain *domain, struct iommu_domain_ser **ser); void iommu_unpreserve_domain(struct iommu_domain *domain); int iommu_preserve_device(struct iommu_domain *domain, @@ -68,6 +98,21 @@ static inline void *dev_iommu_preserved_state(struct device *dev) return NULL; } +static inline void *iommu_domain_restored_state(struct iommu_domain *domain) +{ + return NULL; +} + +static inline int iommu_for_each_preserved_device(iommu_preserved_device_iter_fn fn, void *arg) +{ + return -EOPNOTSUPP; +} + +static inline struct iommu_hw_ser *iommu_get_preserved_data(u64 token, enum iommu_type_ser type) +{ + return NULL; +} + static inline int iommu_preserve_domain(struct iommu_domain *domain, struct iommu_domain_ser **ser) { return -EOPNOTSUPP; -- 2.55.0.1082.g2b9226bbc0-goog