From 54b47585db6658a5eb898d4d45be18d1e581c1bf Mon Sep 17 00:00:00 2001 From: Nicolin Chen Date: Mon, 27 Mar 2023 02:33:47 -0700 Subject: iommufd: Create access in vfio_iommufd_emulated_bind() There are needs to created iommufd_access prior to have an IOAS and set IOAS later. Like the vfio device cdev needs to have an iommufd object to represent the bond (iommufd_access) and IOAS replacement. Moves the iommufd_access_create() call into vfio_iommufd_emulated_bind(), making it symmetric with the __vfio_iommufd_access_destroy() call in the vfio_iommufd_emulated_unbind(). This means an access is created/destroyed by the bind()/unbind(), and the vfio_iommufd_emulated_attach_ioas() only updates the access->ioas pointer. Since vfio_iommufd_emulated_bind() does not provide ioas_id, drop it from the argument list of iommufd_access_create(). Instead, add a new access API iommufd_access_attach() to set the access->ioas pointer. Also, set vdev->iommufd_attached accordingly, similar to the physical pathway. Link: https://lore.kernel.org/r/20230327093351.44505-3-yi.l.liu@intel.com Reviewed-by: Kevin Tian Reviewed-by: Jason Gunthorpe Tested-by: Terrence Xu Tested-by: Nicolin Chen Signed-off-by: Nicolin Chen Signed-off-by: Yi Liu Acked-by: Alex Williamson Signed-off-by: Jason Gunthorpe --- drivers/iommu/iommufd/device.c | 52 +++++++++++++++++++++++----------------- drivers/iommu/iommufd/selftest.c | 5 +++- drivers/vfio/iommufd.c | 24 +++++++++++++------ include/linux/iommufd.h | 3 ++- 4 files changed, 53 insertions(+), 31 deletions(-) diff --git a/drivers/iommu/iommufd/device.c b/drivers/iommu/iommufd/device.c index a0c66f47a65a..ff6fca0ea269 100644 --- a/drivers/iommu/iommufd/device.c +++ b/drivers/iommu/iommufd/device.c @@ -412,15 +412,17 @@ void iommufd_access_destroy_object(struct iommufd_object *obj) struct iommufd_access *access = container_of(obj, struct iommufd_access, obj); - iopt_remove_access(&access->ioas->iopt, access); + if (access->ioas) { + iopt_remove_access(&access->ioas->iopt, access); + refcount_dec(&access->ioas->obj.users); + access->ioas = NULL; + } iommufd_ctx_put(access->ictx); - refcount_dec(&access->ioas->obj.users); } /** * iommufd_access_create - Create an iommufd_access * @ictx: iommufd file descriptor - * @ioas_id: ID for a IOMMUFD_OBJ_IOAS * @ops: Driver's ops to associate with the access * @data: Opaque data to pass into ops functions * @@ -431,12 +433,10 @@ void iommufd_access_destroy_object(struct iommufd_object *obj) * The provided ops are required to use iommufd_access_pin_pages(). */ struct iommufd_access * -iommufd_access_create(struct iommufd_ctx *ictx, u32 ioas_id, +iommufd_access_create(struct iommufd_ctx *ictx, const struct iommufd_access_ops *ops, void *data) { struct iommufd_access *access; - struct iommufd_object *obj; - int rc; /* * There is no uAPI for the access object, but to keep things symmetric @@ -449,21 +449,10 @@ iommufd_access_create(struct iommufd_ctx *ictx, u32 ioas_id, access->data = data; access->ops = ops; - obj = iommufd_get_object(ictx, ioas_id, IOMMUFD_OBJ_IOAS); - if (IS_ERR(obj)) { - rc = PTR_ERR(obj); - goto out_abort; - } - access->ioas = container_of(obj, struct iommufd_ioas, obj); - iommufd_ref_to_users(obj); - if (ops->needs_pin_pages) access->iova_alignment = PAGE_SIZE; else access->iova_alignment = 1; - rc = iopt_add_access(&access->ioas->iopt, access); - if (rc) - goto out_put_ioas; /* The calling driver is a user until iommufd_access_destroy() */ refcount_inc(&access->obj.users); @@ -471,11 +460,6 @@ iommufd_access_create(struct iommufd_ctx *ictx, u32 ioas_id, iommufd_ctx_get(ictx); iommufd_object_finalize(ictx, &access->obj); return access; -out_put_ioas: - refcount_dec(&access->ioas->obj.users); -out_abort: - iommufd_object_abort(ictx, &access->obj); - return ERR_PTR(rc); } EXPORT_SYMBOL_NS_GPL(iommufd_access_create, IOMMUFD); @@ -494,6 +478,30 @@ void iommufd_access_destroy(struct iommufd_access *access) } EXPORT_SYMBOL_NS_GPL(iommufd_access_destroy, IOMMUFD); +int iommufd_access_attach(struct iommufd_access *access, u32 ioas_id) +{ + struct iommufd_ioas *new_ioas; + int rc = 0; + + if (access->ioas) + return -EINVAL; + + new_ioas = iommufd_get_ioas(access->ictx, ioas_id); + if (IS_ERR(new_ioas)) + return PTR_ERR(new_ioas); + + rc = iopt_add_access(&new_ioas->iopt, access); + if (rc) { + iommufd_put_object(&new_ioas->obj); + return rc; + } + iommufd_ref_to_users(&new_ioas->obj); + + access->ioas = new_ioas; + return 0; +} +EXPORT_SYMBOL_NS_GPL(iommufd_access_attach, IOMMUFD); + /** * iommufd_access_notify_unmap - Notify users of an iopt to stop using it * @iopt: iopt to work on diff --git a/drivers/iommu/iommufd/selftest.c b/drivers/iommu/iommufd/selftest.c index 8667eb222cf1..1e89e1a8c5f0 100644 --- a/drivers/iommu/iommufd/selftest.c +++ b/drivers/iommu/iommufd/selftest.c @@ -571,7 +571,7 @@ static int iommufd_test_create_access(struct iommufd_ucmd *ucmd, } access = iommufd_access_create( - ucmd->ictx, ioas_id, + ucmd->ictx, (flags & MOCK_FLAGS_ACCESS_CREATE_NEEDS_PIN_PAGES) ? &selftest_access_ops_pin : &selftest_access_ops, @@ -580,6 +580,9 @@ static int iommufd_test_create_access(struct iommufd_ucmd *ucmd, rc = PTR_ERR(access); goto out_put_fdno; } + rc = iommufd_access_attach(access, ioas_id); + if (rc) + goto out_destroy; cmd->create_access.out_access_fd = fdno; rc = iommufd_ucmd_respond(ucmd, sizeof(*cmd)); if (rc) diff --git a/drivers/vfio/iommufd.c b/drivers/vfio/iommufd.c index db4efbd56042..0695a06db30d 100644 --- a/drivers/vfio/iommufd.c +++ b/drivers/vfio/iommufd.c @@ -138,10 +138,18 @@ static const struct iommufd_access_ops vfio_user_ops = { int vfio_iommufd_emulated_bind(struct vfio_device *vdev, struct iommufd_ctx *ictx, u32 *out_device_id) { + struct iommufd_access *user; + lockdep_assert_held(&vdev->dev_set->lock); - vdev->iommufd_ictx = ictx; iommufd_ctx_get(ictx); + user = iommufd_access_create(ictx, &vfio_user_ops, vdev); + if (IS_ERR(user)) { + iommufd_ctx_put(ictx); + return PTR_ERR(user); + } + vdev->iommufd_access = user; + vdev->iommufd_ictx = ictx; return 0; } EXPORT_SYMBOL_GPL(vfio_iommufd_emulated_bind); @@ -152,6 +160,7 @@ void vfio_iommufd_emulated_unbind(struct vfio_device *vdev) if (vdev->iommufd_access) { iommufd_access_destroy(vdev->iommufd_access); + vdev->iommufd_attached = false; vdev->iommufd_access = NULL; } iommufd_ctx_put(vdev->iommufd_ictx); @@ -161,15 +170,16 @@ EXPORT_SYMBOL_GPL(vfio_iommufd_emulated_unbind); int vfio_iommufd_emulated_attach_ioas(struct vfio_device *vdev, u32 *pt_id) { - struct iommufd_access *user; + int rc; lockdep_assert_held(&vdev->dev_set->lock); - user = iommufd_access_create(vdev->iommufd_ictx, *pt_id, &vfio_user_ops, - vdev); - if (IS_ERR(user)) - return PTR_ERR(user); - vdev->iommufd_access = user; + if (vdev->iommufd_attached) + return -EBUSY; + rc = iommufd_access_attach(vdev->iommufd_access, *pt_id); + if (rc) + return rc; + vdev->iommufd_attached = true; return 0; } EXPORT_SYMBOL_GPL(vfio_iommufd_emulated_attach_ioas); diff --git a/include/linux/iommufd.h b/include/linux/iommufd.h index c0b5b3ac34f1..155d3630aedc 100644 --- a/include/linux/iommufd.h +++ b/include/linux/iommufd.h @@ -40,9 +40,10 @@ enum { }; struct iommufd_access * -iommufd_access_create(struct iommufd_ctx *ictx, u32 ioas_id, +iommufd_access_create(struct iommufd_ctx *ictx, const struct iommufd_access_ops *ops, void *data); void iommufd_access_destroy(struct iommufd_access *access); +int iommufd_access_attach(struct iommufd_access *access, u32 ioas_id); void iommufd_ctx_get(struct iommufd_ctx *ictx); -- cgit v1.2.3