| Message ID | 5288cec9804e7e394be3b7de6b246d8ca9c4792a.1746757630.git.nicolinc@nvidia.com |
|---|---|
| State | New |
| Headers | show |
| Series | iommufd: Add vIOMMU infrastructure (Part-4 HW QUEUE) | expand |
On Fri, May 16, 2025 at 10:28:45AM -0300, Jason Gunthorpe wrote: > On Thu, May 15, 2025 at 07:05:45PM -0700, Nicolin Chen wrote: > > > Otherwise, they would be something like: > > // in my_viommu_alloc() > > my_viommu = iommufd_viommu_alloc(ucmd, ...); > > iommufd_viommu_alloc_mmap(ucmd->ictx, my_viommu, ...); > > iommufd_viommu_destroy_mmap(ucmd->ictx, my_viommu, ...); > > // in my_viommu_destory() > > iommufd_viommu_destroy_mmap(my_viommu->ictx, my_viommu ...); > > Yes, this is how the other objects work.. > > > That being said, I ended up doing something more in this patch > > for the ucmd rework and Kevin's comments: > > > > diff --git a/drivers/iommu/iommufd/iommufd_private.h b/drivers/iommu/iommufd/iommufd_private.h > > index 98fe5a49c9606..ddd144031af5d 100644 > > --- a/drivers/iommu/iommufd/iommufd_private.h > > +++ b/drivers/iommu/iommufd/iommufd_private.h > > @@ -136,14 +136,6 @@ int iopt_pin_pages(struct io_pagetable *iopt, unsigned long iova, > > void iopt_unpin_pages(struct io_pagetable *iopt, unsigned long iova, > > unsigned long length); > > > > -struct iommufd_ucmd { > > - struct iommufd_ctx *ictx; > > - void __user *ubuffer; > > - u32 user_size; > > - void *cmd; > > - struct iommufd_object *alloced_obj; > > -}; > > You don't need to move this unless you are using inlines. Just use a > forward declaration. Since we forward ucmd now, ictx is in the ucmd so we need this structure for: - if (!IS_ERR(ret)) \ + if (!IS_ERR(ret)) { \ ret->member.ops = viommu_ops; \ + ret->member.ictx = ucmd->ictx; \ + } \ Or, we could have a smaller: #define ucmd_to_ictx(ucmd) (struct iommufd_ctx *)(ucmd) and add a line of comments in struct iommufd_ucmd: struct iommufd_ucmd { - struct iommufd_ctx *ictx; + struct iommufd_ctx *ictx; /* Do not move; must be the first member */ void __user *ubuffer; u32 user_size; void *cmd; struct iommufd_object *alloced_obj; }; Thanks Nicolin
diff --git a/include/linux/iommufd.h b/include/linux/iommufd.h index 422eda95d19e..dc6535e848df 100644 --- a/include/linux/iommufd.h +++ b/include/linux/iommufd.h @@ -262,8 +262,10 @@ static inline int iommufd_viommu_report_event(struct iommufd_viommu *viommu, 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)) \ + if (!IS_ERR(ret)) { \ ret->member.ops = viommu_ops; \ + ret->member.ictx = ictx; \ + } \ ret; \ })
When an IOMMU driver calls iommufd_viommu_alloc(), it must pass in an ictx pointer as the underlying _iommufd_object_alloc() helper function requires that to allocate a new object. However, neither the iommufd_viommu_alloc() nor its underlying _iommufd_object_alloc() saves the ictx in the allocated viommu object, although viommu could hold an ictx pointer. When the IOMMU driver wants to use another iommufd function passing in the allocated viommu, it could have avoided passing in the ictx pointer again, if viommu->ictx is valid. Save ictx to viommu->ictx in the iommufd_viommu_alloc(), in order to ease a new vIOMMU-based helper that would then get the ictx from viommu->ictx. Signed-off-by: Nicolin Chen <nicolinc@nvidia.com> --- include/linux/iommufd.h | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)