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, put
the for-driver allocation helpers into a new viommu_api file building with
CONFIG_IOMMUFD_DRIVER.
Signed-off-by: Nicolin Chen <nicol...@nvidia.com>
---
drivers/iommu/iommufd/Makefile | 2 +-
drivers/iommu/iommufd/iommufd_private.h | 1 +
include/linux/iommu.h | 14 ++++++
include/linux/iommufd.h | 43 +++++++++++++++++++
drivers/iommu/iommufd/main.c | 32 --------------
drivers/iommu/iommufd/viommu_api.c | 57 +++++++++++++++++++++++++
6 files changed, 116 insertions(+), 33 deletions(-)
create mode 100644 drivers/iommu/iommufd/viommu_api.c
diff --git a/drivers/iommu/iommufd/Makefile b/drivers/iommu/iommufd/Makefile
index cf4605962bea..93daedd7e5c8 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 viommu_api.o
diff --git a/drivers/iommu/iommufd/iommufd_private.h
b/drivers/iommu/iommufd/iommufd_private.h
index f2f3a906eac9..6a364073f699 100644
--- a/drivers/iommu/iommufd/iommufd_private.h
+++ b/drivers/iommu/iommufd/iommufd_private.h
@@ -131,6 +131,7 @@ enum iommufd_object_type {
IOMMUFD_OBJ_IOAS,
IOMMUFD_OBJ_ACCESS,
IOMMUFD_OBJ_FAULT,
+ IOMMUFD_OBJ_VIOMMU,
#ifdef CONFIG_IOMMUFD_TEST
IOMMUFD_OBJ_SELFTEST,
#endif
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index c8d18f5f644e..3a50f57b0861 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 +544,13 @@ 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 an @iommu_dev as the group of
+ * virtualization resources shared/passed to user space IOMMU
+ * instance. Associate it with a nesting parent @domain. The
+ * @viommu_type must be defined in 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 +600,11 @@ struct iommu_ops {
void (*remove_dev_pasid)(struct device *dev, ioasid_t pasid,
struct iommu_domain *domain);
+ struct iommufd_viommu *(*viommu_alloc)(struct iommu_device *iommu_dev,
+ struct iommu_domain *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 6b9d46981870..069a38999cdd 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;
/* Base struct for all objects with a userspace ID handle. */
@@ -63,6 +64,26 @@ 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);
@@ -79,6 +100,9 @@ int iommufd_access_rw(struct iommufd_access *access,
unsigned long iova,
int iommufd_vfio_compat_ioas_get_id(struct iommufd_ctx *ictx, u32
*out_ioas_id);
int iommufd_vfio_compat_ioas_create(struct iommufd_ctx *ictx);
int iommufd_vfio_compat_set_no_iommu(struct iommufd_ctx *ictx);
+struct iommufd_viommu *
+__iommufd_viommu_alloc(struct iommufd_ctx *ictx, size_t size,
+ const struct iommufd_viommu_ops *ops);
#else /* !CONFIG_IOMMUFD */
static inline struct iommufd_ctx *iommufd_ctx_from_file(struct file *file)
{
@@ -119,5 +143,24 @@ static inline int iommufd_vfio_compat_set_no_iommu(struct
iommufd_ctx *ictx)
{
return -EOPNOTSUPP;
}
+
+static inline struct iommufd_viommu *
+__iommufd_viommu_alloc(struct iommufd_ctx *ictx, size_t size,
+ const struct iommufd_viommu_ops *ops)
+{
+ return ERR_PTR(-EOPNOTSUPP);
+}
#endif /* CONFIG_IOMMUFD */
+
+/*
+ * Helpers for IOMMU driver to allocate driver structures that will be freed by
+ * the iommufd core. Yet, a driver is responsible for its own struct cleanup.
+ */
+#define iommufd_viommu_alloc(ictx, drv_struct, member, ops)
\
+ container_of(__iommufd_viommu_alloc(ictx, \
+ sizeof(struct drv_struct) + \
+ BUILD_BUG_ON_ZERO(offsetof( \
+ struct drv_struct, member)), \
+ ops), \
+ struct drv_struct, member)
#endif
diff --git a/drivers/iommu/iommufd/main.c b/drivers/iommu/iommufd/main.c
index 28e1ef5666e9..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_elm(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.
*
diff --git a/drivers/iommu/iommufd/viommu_api.c
b/drivers/iommu/iommufd/viommu_api.c
new file mode 100644
index 000000000000..c1731f080d6b
--- /dev/null
+++ b/drivers/iommu/iommufd/viommu_api.c
@@ -0,0 +1,57 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (c) 2024, NVIDIA CORPORATION & AFFILIATES
+ */
+
+#include "iommufd_private.h"
+
+struct iommufd_object *iommufd_object_alloc_elm(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_elm, IOMMUFD);
+
+struct iommufd_viommu *
+__iommufd_viommu_alloc(struct iommufd_ctx *ictx, size_t size,
+ const struct iommufd_viommu_ops *ops)
+{
+ struct iommufd_viommu *viommu;
+ struct iommufd_object *obj;
+
+ if (WARN_ON(size < sizeof(*viommu)))
+ return ERR_PTR(-EINVAL);
+ obj = iommufd_object_alloc_elm(ictx, size, IOMMUFD_OBJ_VIOMMU);
+ if (IS_ERR(obj))
+ return ERR_CAST(obj);
+ viommu = container_of(obj, struct iommufd_viommu, obj);
+ if (ops)
+ viommu->ops = ops;
+ return viommu;
+}
+EXPORT_SYMBOL_NS_GPL(__iommufd_viommu_alloc, IOMMUFD);
--
2.43.0
