[PATCH RFCv1 11/14] iommufd: Add struct iommufd_vqueue and its related viommu ops

Nicolin Chen
2024-04-13T03:48:07Z

Inroduce a new core structure and its allocator iommufd_vqueue_alloc().

This can be used for a viommu to allocate a HW-accelerated queue, e.g.
NVIDIA's virtual command queue and AMD vIOMMU's command buffer.

Also add a pair of viommu ops for iommufd to forward user space ioctls
to IOMMU drivers.

Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
---
drivers/iommu/iommufd/viommu.c | 1 +
include/linux/iommu.h | 1 +
include/linux/iommufd.h | 27 +++++++++++++++++++++++++++
3 files changed, 29 insertions(+)

diff --git a/drivers/iommu/iommufd/viommu.c b/drivers/iommu/iommufd/viommu.c
index 71baca0c75de..8894878c1e73 100644
--- a/drivers/iommu/iommufd/viommu.c
+++ b/drivers/iommu/iommufd/viommu.c
@@ -19,6 +19,7 @@
}

viommu_struct_alloc(viommu);
+viommu_struct_alloc(vqueue);

void iommufd_viommu_destroy(struct iommufd_object *obj)
{
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 4d4461146288..475f41f2d41f 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -146,6 +146,7 @@ struct iopf_queue {
};

struct iommufd_viommu;
+struct iommufd_vqueue;

/* iommu fault flags */
#define IOMMU_FAULT_READ 0x0
diff --git a/include/linux/iommufd.h b/include/linux/iommufd.h
index 2be302b82f47..5b97b04aa145 100644
--- a/include/linux/iommufd.h
+++ b/include/linux/iommufd.h
@@ -20,6 +20,7 @@ struct iommufd_access;
struct iommufd_hwpt_paging;
struct file;
struct iommu_group;
+struct iommu_user_data;

enum iommufd_object_type {
IOMMUFD_OBJ_NONE,
@@ -97,12 +98,27 @@ struct iommufd_viommu {
* @free: Free all driver-specific parts of an iommufd_viommu. The memory
* of the entire viommu will be free-ed by iommufd core
* @set/unset_dev_id: set/unset a user space virtual id for a device
+ * @vqueue_alloc: Allocate an iommufd_vqueue as a user space command queue for a
+ * @viommu instance. Queue specific @user_data must be defined in
+ * the include/uapi/linux/iommufd.h header.
+ * @vqueue_free: Free all driver-specific parts of an iommufd_vqueue. The memory
+ * of the iommufd_vqueue will be free-ed by iommufd core
*/
struct iommufd_viommu_ops {
void (*free)(struct iommufd_viommu *viommu);
int (*set_dev_id)(struct iommufd_viommu *viommu,
struct device *dev, u64 dev_id);
void (*unset_dev_id)(struct iommufd_viommu *viommu, struct device *dev);
+ struct iommufd_vqueue *(*vqueue_alloc)(
+ struct iommufd_viommu *viommu,
+ const struct iommu_user_data *user_data);
+ void (*vqueue_free)(struct iommufd_vqueue *vqueue);
+};
+
+struct iommufd_vqueue {
+ struct iommufd_object obj;
+ struct iommufd_ctx *ictx;
+ struct iommufd_viommu *viommu;
};

#if IS_ENABLED(CONFIG_IOMMUFD)
@@ -123,6 +139,7 @@ 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(size_t size);
+struct iommufd_vqueue *_iommufd_vqueue_alloc(size_t size);
#else /* !CONFIG_IOMMUFD */
static inline struct iommufd_ctx *iommufd_ctx_from_file(struct file *file)
{
@@ -168,6 +185,11 @@ static inline struct iommufd_viommu *_iommufd_viommu_alloc(size_t size)
{
return NULL;
}
+
+static inline struct iommufd_vqueue *_iommufd_vqueue_alloc(size_t size)
+{
+ return NULL;
+}
#endif /* CONFIG_IOMMUFD */

/*
@@ -179,4 +201,9 @@ static inline struct iommufd_viommu *_iommufd_viommu_alloc(size_t size)
BUILD_BUG_ON_ZERO(offsetof( \
struct drv_struct, member))), \
struct drv_struct, member)
+#define iommufd_vqueue_alloc(drv_struct, member) \
+ container_of(_iommufd_vqueue_alloc(sizeof(struct drv_struct) + \
+ BUILD_BUG_ON_ZERO(offsetof( \
+ struct drv_struct, member))), \
+ struct drv_struct, member)
#endif
--
2.43.0