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
- 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
- Non-affiliated event reporting
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,
};
To make the Kernel config work between a driver and the iommufd core, move
the _iommufd_object_alloc helper into a new driver.c file that builds with
CONFIG_IOMMUFD_DRIVER.
Suggested-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
Signed-off-by: Nicolin Chen <nicolinc@xxxxxxxxxx>
---
drivers/iommu/iommufd/Makefile | 2 +-
drivers/iommu/iommufd/iommufd_private.h | 4 --
include/linux/iommu.h | 14 +++++++
include/linux/iommufd.h | 56 +++++++++++++++++++++++++
drivers/iommu/iommufd/driver.c | 38 +++++++++++++++++
drivers/iommu/iommufd/main.c | 32 --------------
6 files changed, 109 insertions(+), 37 deletions(-)
create mode 100644 drivers/iommu/iommufd/driver.c
diff --git a/drivers/iommu/iommufd/Makefile b/drivers/iommu/iommufd/Makefile
index cf4605962bea..435124a8e1f1 100644
--- a/drivers/iommu/iommufd/Makefile
+++ b/drivers/iommu/iommufd/Makefile
@@ -12,4 +12,4 @@ iommufd-y := \
iommufd-$(CONFIG_IOMMUFD_TEST) += selftest.o
obj-$(CONFIG_IOMMUFD) += iommufd.o
-obj-$(CONFIG_IOMMUFD_DRIVER) += iova_bitmap.o
+obj-$(CONFIG_IOMMUFD_DRIVER) += iova_bitmap.o driver.o
diff --git a/drivers/iommu/iommufd/iommufd_private.h b/drivers/iommu/iommufd/iommufd_private.h
index 1bb8c0aaecd1..5bd41257f2ef 100644
--- a/drivers/iommu/iommufd/iommufd_private.h
+++ b/drivers/iommu/iommufd/iommufd_private.h
@@ -202,10 +202,6 @@ iommufd_object_put_and_try_destroy(struct iommufd_ctx *ictx,
iommufd_object_remove(ictx, obj, obj->id, 0);
}
-struct iommufd_object *_iommufd_object_alloc(struct iommufd_ctx *ictx,
- size_t size,
- enum iommufd_object_type type);
-
#define __iommufd_object_alloc(ictx, ptr, type, obj) \
container_of(_iommufd_object_alloc( \
ictx, \
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 4ad9b9ec6c9b..14f24b5cd16f 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 suggested 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 22948dd03d67..55054fbc793c 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
+ * @free: Free all driver-specific parts of an iommufd_viommu. The memory of the
+ * vIOMMU will be free-ed by iommufd core after calling this free op.
+ */
+struct iommufd_viommu_ops {
+ void (*free)(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);
@@ -135,4 +157,38 @@ static inline int iommufd_vfio_compat_set_no_iommu(struct iommufd_ctx *ictx)
return -EOPNOTSUPP;
}
#endif /* CONFIG_IOMMUFD */
+
+#if IS_ENABLED(CONFIG_IOMMUFD_DRIVER)
+struct iommufd_object *_iommufd_object_alloc(struct iommufd_ctx *ictx,
+ size_t size,
+ enum iommufd_object_type type);
+#else /* !CONFIG_IOMMUFD_DRIVER */
+static inline struct iommufd_object *
+_iommufd_object_alloc(struct iommufd_ctx *ictx, size_t size,
+ enum iommufd_object_type type)
+{
+ return ERR_PTR(-EOPNOTSUPP);
+}
+#endif /* CONFIG_IOMMUFD_DRIVER */
+
+/*
+ * 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) \
+ ({ \
+ struct drv_struct *ret; \
+ \
+ static_assert( \
+ __same_type(struct iommufd_viommu, \
+ ((struct drv_struct *)NULL)->member)); \
+ static_assert(offsetof(struct drv_struct, member.obj) == 0); \
+ ret = container_of( \
+ _iommufd_object_alloc(ictx, sizeof(struct drv_struct), \
+ IOMMUFD_OBJ_VIOMMU), \
+ struct drv_struct, member.obj); \
+ if (!IS_ERR(ret)) \
+ ret->member.ops = viommu_ops; \
+ ret; \
+ })
#endif
diff --git a/drivers/iommu/iommufd/driver.c b/drivers/iommu/iommufd/driver.c
new file mode 100644
index 000000000000..c0876d3f91c7
--- /dev/null
+++ b/drivers/iommu/iommufd/driver.c
@@ -0,0 +1,38 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (c) 2024, NVIDIA CORPORATION & AFFILIATES
+ */
+
+#include "iommufd_private.h"
+
+struct iommufd_object *_iommufd_object_alloc(struct iommufd_ctx *ictx,
+ size_t size,
+ enum iommufd_object_type type)
+{
+ struct iommufd_object *obj;
+ int rc;
+
+ obj = kzalloc(size, GFP_KERNEL_ACCOUNT);
+ if (!obj)
+ return ERR_PTR(-ENOMEM);
+ obj->type = type;
+ /* Starts out bias'd by 1 until it is removed from the xarray */
+ refcount_set(&obj->shortterm_users, 1);
+ refcount_set(&obj->users, 1);
+
+ /*
+ * Reserve an ID in the xarray but do not publish the pointer yet since
+ * the caller hasn't initialized it yet. Once the pointer is published
+ * in the xarray and visible to other threads we can't reliably destroy
+ * it anymore, so the caller must complete all errorable operations
+ * before calling iommufd_object_finalize().
+ */
+ rc = xa_alloc(&ictx->objects, &obj->id, XA_ZERO_ENTRY, xa_limit_31b,
+ GFP_KERNEL_ACCOUNT);
+ if (rc)
+ goto out_free;
+ return obj;
+out_free:
+ kfree(obj);
+ return ERR_PTR(rc);
+}
+EXPORT_SYMBOL_NS_GPL(_iommufd_object_alloc, IOMMUFD);
diff --git a/drivers/iommu/iommufd/main.c b/drivers/iommu/iommufd/main.c
index b5f5d27ee963..92bd075108e5 100644
--- a/drivers/iommu/iommufd/main.c
+++ b/drivers/iommu/iommufd/main.c
@@ -29,38 +29,6 @@ struct iommufd_object_ops {
static const struct iommufd_object_ops iommufd_object_ops[];
static struct miscdevice vfio_misc_dev;
-struct iommufd_object *_iommufd_object_alloc(struct iommufd_ctx *ictx,
- size_t size,
- enum iommufd_object_type type)
-{
- struct iommufd_object *obj;
- int rc;
-
- obj = kzalloc(size, GFP_KERNEL_ACCOUNT);
- if (!obj)
- return ERR_PTR(-ENOMEM);
- obj->type = type;
- /* Starts out bias'd by 1 until it is removed from the xarray */
- refcount_set(&obj->shortterm_users, 1);
- refcount_set(&obj->users, 1);
-
- /*
- * Reserve an ID in the xarray but do not publish the pointer yet since
- * the caller hasn't initialized it yet. Once the pointer is published
- * in the xarray and visible to other threads we can't reliably destroy
- * it anymore, so the caller must complete all errorable operations
- * before calling iommufd_object_finalize().
- */
- rc = xa_alloc(&ictx->objects, &obj->id, XA_ZERO_ENTRY,
- xa_limit_31b, GFP_KERNEL_ACCOUNT);
- if (rc)
- goto out_free;
- return obj;
-out_free:
- kfree(obj);
- return ERR_PTR(rc);
-}
-
/*
* Allow concurrent access to the object.
*
--
2.43.0
