On 22/10/24 11:20, Nicolin Chen wrote:
Introduce a new IOMMUFD_OBJ_VDEVICE to represent a physical device, i.e.
iommufd_device (idev) object, against an iommufd_viommu (vIOMMU) object in
the VM. This vDEVICE object (and its structure) holds all the information
and attributes in a VM, regarding the device related to the vIOMMU.
As an initial patch, add a per-vIOMMU virtual ID. This can be:
- Virtual StreamID on a nested ARM SMMUv3, an index to a Stream Table
- Virtual DeviceID on a nested AMD IOMMU, an index to a Device Table
- Virtual ID on a nested Intel VT-D IOMMU, an index to a Context Table
Potentially, this vDEVICE structure can hold some vData for Confidential
Compute Architecture (CCA).
Add a pair of vdevice_alloc and vdevice_free in struct iommufd_viommu_ops
to allow driver-level vDEVICE structure allocations.
Similar to iommufd_viommu_alloc, add an iommufd_vdevice_alloc helper, so
IOMMU drivers can allocate core-embedded style structures.
Signed-off-by: Nicolin Chen <nicolinc@xxxxxxxxxx>
---
include/linux/iommufd.h | 32 ++++++++++++++++++++++++++++++++
1 file changed, 32 insertions(+)
diff --git a/include/linux/iommufd.h b/include/linux/iommufd.h
index 5c13c35952d8..5d61a1d2947a 100644
--- a/include/linux/iommufd.h
+++ b/include/linux/iommufd.h
@@ -31,6 +31,7 @@ enum iommufd_object_type {
IOMMUFD_OBJ_ACCESS,
IOMMUFD_OBJ_FAULT,
IOMMUFD_OBJ_VIOMMU,
+ IOMMUFD_OBJ_VDEVICE,
#ifdef CONFIG_IOMMUFD_TEST
IOMMUFD_OBJ_SELFTEST,
#endif
@@ -92,6 +93,14 @@ struct iommufd_viommu {
unsigned int type;
};
+struct iommufd_vdevice {
+ struct iommufd_object obj;
+ struct iommufd_ctx *ictx;
+ struct iommufd_device *idev;
+ struct iommufd_viommu *viommu;
+ u64 id; /* per-vIOMMU virtual ID */
+};
+
/**
* struct iommufd_viommu_ops - vIOMMU specific operations
* @free: Free all driver-specific parts of an iommufd_viommu. The memory of the
@@ -101,12 +110,24 @@ struct iommufd_viommu {
* must be defined in include/uapi/linux/iommufd.h.
* It must fully initialize the new iommu_domain before
* returning. Upon failure, ERR_PTR must be returned.
+ * @vdevice_alloc: Allocate a driver-managed iommufd_vdevice to init some driver
+ * specific structure or HW procedure. Note that the core-level
+ * structure is filled by the iommufd core after calling this op.
+ * It is suggested to call iommufd_vdevice_alloc() helper for
+ * a bundled allocation of the core and the driver structures,
+ * using the ictx pointer in the given @viommu.
+ * @vdevice_free: Free a driver-managed iommufd_vdevice to de-init its structure
+ * or HW procedure. The memory of the vdevice will be free-ed by
+ * iommufd core.
*/
struct iommufd_viommu_ops {
void (*free)(struct iommufd_viommu *viommu);
struct iommu_domain *(*domain_alloc_nested)(
struct iommufd_viommu *viommu,
const struct iommu_user_data *user_data);
+ struct iommufd_vdevice *(*vdevice_alloc)(struct iommufd_viommu *viommu,
+ struct device *dev, u64 id);
+ void (*vdevice_free)(struct iommufd_vdevice *vdev);
};
#if IS_ENABLED(CONFIG_IOMMUFD)
@@ -200,4 +221,15 @@ _iommufd_object_alloc(struct iommufd_ctx *ictx, size_t size,
ret->member.ops = viommu_ops; \
ret; \
})
+#define iommufd_vdevice_alloc(ictx, drv_struct, member) \
+ ({ \
+ static_assert( \
+ __same_type(struct iommufd_vdevice, \
+ ((struct drv_struct *)NULL)->member)); \
+ static_assert(offsetof(struct drv_struct, member.obj) == 0); \
+ container_of(_iommufd_object_alloc(ictx, \
+ sizeof(struct drv_struct), \
+ IOMMUFD_OBJ_VDEVICE), \
+ struct drv_struct, member.obj); \
+ })
#endif
A nit: it hurts eyes to read:
mock_vdev = iommufd_vdevice_alloc(viommu->ictx, mock_vdevice, core);
vs.
mock_vdev = iommufd_vdevice_alloc(viommu->ictx, struct mock_vdevice, core);
as for the former I go searching for a "mock_vdevice" variable and for
the latter it is clear it is 1) a macro 2) which does some type checking.
also, it makes it impossible to pass things like typeof(..) or a type
from typedef. Thanks,
--
Alexey
