Add a new IOMMUFD_OBJ_VIOMMU with an iommufd_viommu structure to represent
a slice of physical IOMMU device passed to or shared with a user space VM.
This slice, now a vIOMMU object, is a group of virtualization resources of
a physical IOMMU's, such as:
- Security namespace for guest owned ID, e.g. guest-controlled cache tags
- Non-device-affiliated event reporting, e.g. invalidation queue errors
- Access to a sharable nesting parent pagetable across physical IOMMUs
- Virtualization of various platforms IDs, e.g. RIDs and others
- Delivery of paravirtualized invalidation
- Direct assigned invalidation queues
- Direct assigned interrupts
Add a new viommu_alloc op in iommu_ops, for drivers to allocate their own
vIOMMU structures. And this allocation also needs a free(), so add struct
iommufd_viommu_ops.
To simplify a vIOMMU allocation, provide a iommufd_viommu_alloc() helper.
It's suggested that a driver should embed a core-level viommu structure in
its driver-level viommu struct and call the iommufd_viommu_alloc() helper,
meanwhile the driver can also implement a viommu ops:
struct my_driver_viommu {
struct iommufd_viommu core;
/* driver-owned properties/features */
....
};
static const struct iommufd_viommu_ops my_driver_viommu_ops = {
.free = my_driver_viommu_free,
/* future ops for virtualization features */
....
};
static struct iommufd_viommu my_driver_viommu_alloc(...)
{
struct my_driver_viommu *my_viommu =
iommufd_viommu_alloc(ictx, my_driver_viommu, core,
my_driver_viommu_ops);
/* Init my_viommu and related HW feature */
....
return &my_viommu->core;
}
static struct iommu_domain_ops my_driver_domain_ops = {
....
.viommu_alloc = my_driver_viommu_alloc,
};
Suggested-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
Reviewed-by: Kevin Tian <kevin.tian@xxxxxxxxx>
Reviewed-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
Signed-off-by: Nicolin Chen <nicolinc@xxxxxxxxxx>
---
include/linux/iommu.h | 14 ++++++++++++++
include/linux/iommufd.h | 40 ++++++++++++++++++++++++++++++++++++++++
2 files changed, 54 insertions(+)
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index bd722f473635..2574fc8abaf2 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -42,6 +42,8 @@ struct notifier_block;
struct iommu_sva;
struct iommu_dma_cookie;
struct iommu_fault_param;
+struct iommufd_ctx;
+struct iommufd_viommu;
#define IOMMU_FAULT_PERM_READ (1 << 0) /* read */
#define IOMMU_FAULT_PERM_WRITE (1 << 1) /* write */
@@ -542,6 +544,14 @@ static inline int __iommu_copy_struct_from_user_array(
* @remove_dev_pasid: Remove any translation configurations of a specific
* pasid, so that any DMA transactions with this pasid
* will be blocked by the hardware.
+ * @viommu_alloc: Allocate an iommufd_viommu on a physical IOMMU instance behind
+ * the @dev, as the set of virtualization resources shared/passed
+ * to user space IOMMU instance. And associate it with a nesting
+ * @parent_domain. The @viommu_type must be defined in the header
+ * include/uapi/linux/iommufd.h
+ * It is required to call iommufd_viommu_alloc() helper for
+ * a bundled allocation of the core and the driver structures,
+ * using the given @ictx pointer.
* @pgsize_bitmap: bitmap of all possible supported page sizes
* @owner: Driver module providing these ops
* @identity_domain: An always available, always attachable identity
@@ -591,6 +601,10 @@ struct iommu_ops {
void (*remove_dev_pasid)(struct device *dev, ioasid_t pasid,
struct iommu_domain *domain);
+ struct iommufd_viommu *(*viommu_alloc)(
+ struct device *dev, struct iommu_domain *parent_domain,
+ struct iommufd_ctx *ictx, unsigned int viommu_type);
+
const struct iommu_domain_ops *default_domain_ops;
unsigned long pgsize_bitmap;
struct module *owner;
diff --git a/include/linux/iommufd.h b/include/linux/iommufd.h
index 2f72452fad27..457e763e8b63 100644
--- a/include/linux/iommufd.h
+++ b/include/linux/iommufd.h
@@ -17,6 +17,7 @@ struct iommu_group;
struct iommufd_access;
struct iommufd_ctx;
struct iommufd_device;
+struct iommufd_viommu_ops;
struct page;
enum iommufd_object_type {
@@ -28,6 +29,7 @@ enum iommufd_object_type {
IOMMUFD_OBJ_IOAS,
IOMMUFD_OBJ_ACCESS,
IOMMUFD_OBJ_FAULT,
+ IOMMUFD_OBJ_VIOMMU,
#ifdef CONFIG_IOMMUFD_TEST
IOMMUFD_OBJ_SELFTEST,
#endif
@@ -78,6 +80,26 @@ void iommufd_access_detach(struct iommufd_access *access);
void iommufd_ctx_get(struct iommufd_ctx *ictx);
+struct iommufd_viommu {
+ struct iommufd_object obj;
+ struct iommufd_ctx *ictx;
+ struct iommu_device *iommu_dev;
+ struct iommufd_hwpt_paging *hwpt;
+
+ const struct iommufd_viommu_ops *ops;
+
+ unsigned int type;
+};
+
+/**
+ * struct iommufd_viommu_ops - vIOMMU specific operations
+ * @destroy: Clean up all driver-specific parts of an iommufd_viommu. The memory
+ * of the vIOMMU will be free-ed by iommufd core after calling this op
+ */
+struct iommufd_viommu_ops {
+ void (*destroy)(struct iommufd_viommu *viommu);
+};
+
#if IS_ENABLED(CONFIG_IOMMUFD)
struct iommufd_ctx *iommufd_ctx_from_file(struct file *file);
struct iommufd_ctx *iommufd_ctx_from_fd(int fd);
@@ -145,4 +167,22 @@ _iommufd_object_alloc(struct iommufd_ctx *ictx, size_t size,
return ERR_PTR(-EOPNOTSUPP);
}
#endif /* CONFIG_IOMMUFD */
+
+/*
+ * Helpers for IOMMU driver to allocate driver structures that will be freed by
+ * the iommufd core. The free op will be called prior to freeing the memory.
+ */
+#define iommufd_viommu_alloc(ictx, drv_struct, member, viommu_ops) \
+ ({ \
+ drv_struct *ret; \
+ \
+ static_assert(__same_type(struct iommufd_viommu, \
+ ((drv_struct *)NULL)->member)); \
+ static_assert(offsetof(drv_struct, member.obj) == 0); \
+ ret = (drv_struct *)_iommufd_object_alloc( \
+ ictx, sizeof(drv_struct), IOMMUFD_OBJ_VIOMMU); \
+ if (!IS_ERR(ret)) \
+ ret->member.ops = viommu_ops; \
+ ret; \
+ })
#endif
--
2.43.0
