Hi Sumit, Thanks for your comments, please find my answer below. On ven., 2022-08-12 at 19:36 +0530, Sumit Garg wrote: > Caution: EXT Email > > Hi Olivier, > > On Thu, 11 Aug 2022 at 19:26, Olivier Masse <olivier.masse@xxxxxxx> > wrote: > > > > From: Etienne Carriere <etienne.carriere@xxxxxxxxxx> > > > > This change allows userland to create a tee_shm object that refers > > to a dmabuf reference. > > > > Userland provides a dmabuf file descriptor as buffer reference. > > The created tee_shm object exported as a brand new dmabuf reference > > used to provide a clean fd to userland. Userland shall closed this > > new > > fd to release the tee_shm object resources. The initial dmabuf > > resources > > are tracked independently through original dmabuf file descriptor. > > > > Once the buffer is registered and until it is released, TEE driver > > keeps a refcount on the registered dmabuf structure. > > > > This change only support dmabuf references that relates to > > physically > > contiguous memory buffers. > > What limits you to extend this feature to non-contiguous memory > buffers? I believe that should be possible with OP-TEE dynamic shared > memory which gives you the granularity to register a list of pages. But it will need more logic in OPTEE OS to verify that all pages are in the Secure Data Path protected area. Our solution use a fixed protected reserved memory region and do not rely on a dynamic protection set in secure. Best regards, Olivier > > -Sumit > > > > > New tee_shm flag to identify tee_shm objects built from a > > registered > > dmabuf: TEE_SHM_EXT_DMA_BUF. Such tee_shm structures are flagged > > with > > TEE_SHM_EXT_DMA_BUF. > > > > Co-Developed-by: Etienne Carriere <etienne.carriere@xxxxxxxxxx> > > Signed-off-by: Olivier Masse <olivier.masse@xxxxxxx> > > From: > > https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgithub.com%2Flinaro-swg%2Flinux.git&data=05%7C01%7Colivier.masse%40nxp.com%7C204e0821d1c84355ed4208da7c6be5c6%7C686ea1d3bc2b4c6fa92cd99c5c301635%7C0%7C0%7C637959100100176447%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=MRfnQNbwAIj%2Bnd9tSjSb5Nzrv3sQVpVMIdOxxRfu6U4%3D&reserved=0 > > (cherry picked from commit > > 41e21e5c405530590dc2dd10b2a8dbe64589840f) > > --- > > drivers/tee/tee_core.c | 38 +++++++++++++++ > > drivers/tee/tee_shm.c | 99 > > +++++++++++++++++++++++++++++++++++++++- > > include/linux/tee_drv.h | 11 +++++ > > include/uapi/linux/tee.h | 29 ++++++++++++ > > 4 files changed, 175 insertions(+), 2 deletions(-) > > > > diff --git a/drivers/tee/tee_core.c b/drivers/tee/tee_core.c > > index 8aa1a4836b92..7c45cbf85eb9 100644 > > --- a/drivers/tee/tee_core.c > > +++ b/drivers/tee/tee_core.c > > @@ -355,6 +355,42 @@ tee_ioctl_shm_register(struct tee_context > > *ctx, > > return ret; > > } > > > > +static int tee_ioctl_shm_register_fd(struct tee_context *ctx, > > + struct > > tee_ioctl_shm_register_fd_data __user *udata) > > +{ > > + struct tee_ioctl_shm_register_fd_data data; > > + struct tee_shm *shm; > > + long ret; > > + > > + if (copy_from_user(&data, udata, sizeof(data))) > > + return -EFAULT; > > + > > + /* Currently no input flags are supported */ > > + if (data.flags) > > + return -EINVAL; > > + > > + shm = tee_shm_register_fd(ctx, data.fd); > > + if (IS_ERR(shm)) > > + return -EINVAL; > > + > > + data.id = shm->id; > > + data.flags = shm->flags; > > + data.size = shm->size; > > + > > + if (copy_to_user(udata, &data, sizeof(data))) > > + ret = -EFAULT; > > + else > > + ret = tee_shm_get_fd(shm); > > + > > + /* > > + * When user space closes the file descriptor the shared > > memory > > + * should be freed or if tee_shm_get_fd() failed then it > > will > > + * be freed immediately. > > + */ > > + tee_shm_put(shm); > > + return ret; > > +} > > + > > static int params_from_user(struct tee_context *ctx, struct > > tee_param *params, > > size_t num_params, > > struct tee_ioctl_param __user *uparams) > > @@ -829,6 +865,8 @@ static long tee_ioctl(struct file *filp, > > unsigned int cmd, unsigned long arg) > > return tee_ioctl_shm_alloc(ctx, uarg); > > case TEE_IOC_SHM_REGISTER: > > return tee_ioctl_shm_register(ctx, uarg); > > + case TEE_IOC_SHM_REGISTER_FD: > > + return tee_ioctl_shm_register_fd(ctx, uarg); > > case TEE_IOC_OPEN_SESSION: > > return tee_ioctl_open_session(ctx, uarg); > > case TEE_IOC_INVOKE: > > diff --git a/drivers/tee/tee_shm.c b/drivers/tee/tee_shm.c > > index 836872467dc6..55a3fbbb022e 100644 > > --- a/drivers/tee/tee_shm.c > > +++ b/drivers/tee/tee_shm.c > > @@ -4,6 +4,7 @@ > > */ > > #include <linux/anon_inodes.h> > > #include <linux/device.h> > > +#include <linux/dma-buf.h> > > #include <linux/idr.h> > > #include <linux/mm.h> > > #include <linux/sched.h> > > @@ -12,6 +13,14 @@ > > #include <linux/uio.h> > > #include "tee_private.h" > > > > +/* extra references appended to shm object for registered shared > > memory */ > > +struct tee_shm_dmabuf_ref { > > + struct tee_shm shm; > > + struct dma_buf *dmabuf; > > + struct dma_buf_attachment *attach; > > + struct sg_table *sgt; > > +}; > > + > > static void shm_put_kernel_pages(struct page **pages, size_t > > page_count) > > { > > size_t n; > > @@ -71,7 +80,16 @@ static void release_registered_pages(struct > > tee_shm *shm) > > > > static void tee_shm_release(struct tee_device *teedev, struct > > tee_shm *shm) > > { > > - if (shm->flags & TEE_SHM_POOL) { > > + if (shm->flags & TEE_SHM_EXT_DMA_BUF) { > > + struct tee_shm_dmabuf_ref *ref; > > + > > + ref = container_of(shm, struct tee_shm_dmabuf_ref, > > shm); > > + dma_buf_unmap_attachment(ref->attach, ref->sgt, > > + DMA_BIDIRECTIONAL); > > + > > + dma_buf_detach(ref->dmabuf, ref->attach); > > + dma_buf_put(ref->dmabuf); > > + } else if (shm->flags & TEE_SHM_POOL) { > > teedev->pool->ops->free(teedev->pool, shm); > > } else if (shm->flags & TEE_SHM_DYNAMIC) { > > int rc = teedev->desc->ops->shm_unregister(shm- > > >ctx, shm); > > @@ -195,7 +213,7 @@ struct tee_shm *tee_shm_alloc_user_buf(struct > > tee_context *ctx, size_t size) > > * tee_client_invoke_func(). The memory allocated is later freed > > with a > > * call to tee_shm_free(). > > * > > - * @returns a pointer to 'struct tee_shm' > > + * @returns a pointer to 'struct tee_shm' on success, and ERR_PTR > > on failure > > */ > > struct tee_shm *tee_shm_alloc_kernel_buf(struct tee_context *ctx, > > size_t size) > > { > > @@ -229,6 +247,83 @@ struct tee_shm *tee_shm_alloc_priv_buf(struct > > tee_context *ctx, size_t size) > > } > > EXPORT_SYMBOL_GPL(tee_shm_alloc_priv_buf); > > > > +struct tee_shm *tee_shm_register_fd(struct tee_context *ctx, int > > fd) > > +{ > > + struct tee_shm_dmabuf_ref *ref; > > + int rc; > > + > > + if (!tee_device_get(ctx->teedev)) > > + return ERR_PTR(-EINVAL); > > + > > + teedev_ctx_get(ctx); > > + > > + ref = kzalloc(sizeof(*ref), GFP_KERNEL); > > + if (!ref) { > > + rc = -ENOMEM; > > + goto err_put_tee; > > + } > > + > > + refcount_set(&ref->shm.refcount, 1); > > + ref->shm.ctx = ctx; > > + ref->shm.id = -1; > > + > > + ref->dmabuf = dma_buf_get(fd); > > + if (IS_ERR(ref->dmabuf)) { > > + rc = PTR_ERR(ref->dmabuf); > > + goto err_put_dmabuf; > > + } > > + > > + ref->attach = dma_buf_attach(ref->dmabuf, &ref->shm.ctx- > > >teedev->dev); > > + if (IS_ERR(ref->attach)) { > > + rc = PTR_ERR(ref->attach); > > + goto err_detach; > > + } > > + > > + ref->sgt = dma_buf_map_attachment(ref->attach, > > DMA_BIDIRECTIONAL); > > + if (IS_ERR(ref->sgt)) { > > + rc = PTR_ERR(ref->sgt); > > + goto err_unmap_attachement; > > + } > > + > > + if (sg_nents(ref->sgt->sgl) != 1) { > > + rc = PTR_ERR(ref->sgt->sgl); > > + goto err_unmap_attachement; > > + } > > + > > + ref->shm.paddr = sg_dma_address(ref->sgt->sgl); > > + ref->shm.size = sg_dma_len(ref->sgt->sgl); > > + ref->shm.flags = TEE_SHM_EXT_DMA_BUF; > > + > > + mutex_lock(&ref->shm.ctx->teedev->mutex); > > + ref->shm.id = idr_alloc(&ref->shm.ctx->teedev->idr, &ref- > > >shm, > > + 1, 0, GFP_KERNEL); > > + mutex_unlock(&ref->shm.ctx->teedev->mutex); > > + if (ref->shm.id < 0) { > > + rc = ref->shm.id; > > + goto err_idr_remove; > > + } > > + > > + return &ref->shm; > > + > > +err_idr_remove: > > + mutex_lock(&ctx->teedev->mutex); > > + idr_remove(&ctx->teedev->idr, ref->shm.id); > > + mutex_unlock(&ctx->teedev->mutex); > > +err_unmap_attachement: > > + dma_buf_unmap_attachment(ref->attach, ref->sgt, > > DMA_BIDIRECTIONAL); > > +err_detach: > > + dma_buf_detach(ref->dmabuf, ref->attach); > > +err_put_dmabuf: > > + dma_buf_put(ref->dmabuf); > > + kfree(ref); > > +err_put_tee: > > + teedev_ctx_put(ctx); > > + tee_device_put(ctx->teedev); > > + > > + return ERR_PTR(rc); > > +} > > +EXPORT_SYMBOL_GPL(tee_shm_register_fd); > > + > > static struct tee_shm * > > register_shm_helper(struct tee_context *ctx, unsigned long addr, > > size_t length, u32 flags, int id) > > diff --git a/include/linux/tee_drv.h b/include/linux/tee_drv.h > > index 911cad324acc..40ddd5376c2d 100644 > > --- a/include/linux/tee_drv.h > > +++ b/include/linux/tee_drv.h > > @@ -25,6 +25,7 @@ > > #define TEE_SHM_USER_MAPPED BIT(1) /* Memory mapped in user > > space */ > > #define TEE_SHM_POOL BIT(2) /* Memory allocated from > > pool */ > > #define TEE_SHM_PRIV BIT(3) /* Memory private to TEE > > driver */ > > +#define TEE_SHM_EXT_DMA_BUF BIT(4) /* Memory with dma-buf > > handle */ > > > > struct device; > > struct tee_device; > > @@ -276,6 +277,16 @@ struct tee_shm > > *tee_shm_alloc_kernel_buf(struct tee_context *ctx, size_t size); > > struct tee_shm *tee_shm_register_kernel_buf(struct tee_context > > *ctx, > > void *addr, size_t > > length); > > > > +/** > > + * tee_shm_register_fd() - Register shared memory from file > > descriptor > > + * > > + * @ctx: Context that allocates the shared memory > > + * @fd: Shared memory file descriptor reference > > + * > > + * @returns a pointer to 'struct tee_shm' on success, and ERR_PTR > > on failure > > + */ > > +struct tee_shm *tee_shm_register_fd(struct tee_context *ctx, int > > fd); > > + > > /** > > * tee_shm_is_dynamic() - Check if shared memory object is of the > > dynamic kind > > * @shm: Shared memory handle > > diff --git a/include/uapi/linux/tee.h b/include/uapi/linux/tee.h > > index 25a6c534beb1..6f84060ad005 100644 > > --- a/include/uapi/linux/tee.h > > +++ b/include/uapi/linux/tee.h > > @@ -121,6 +121,35 @@ struct tee_ioctl_shm_alloc_data { > > #define TEE_IOC_SHM_ALLOC _IOWR(TEE_IOC_MAGIC, TEE_IOC_BASE + > > 1, \ > > struct > > tee_ioctl_shm_alloc_data) > > > > +/** > > + * struct tee_ioctl_shm_register_fd_data - Shared memory > > registering argument > > + * @fd: [in] File descriptor identifying the shared > > memory > > + * @size: [out] Size of shared memory to allocate > > + * @flags: [in] Flags to/from allocation. > > + * @id: [out] Identifier of the shared memory > > + * > > + * The flags field should currently be zero as input. Updated by > > the call > > + * with actual flags as defined by TEE_IOCTL_SHM_* above. > > + * This structure is used as argument for TEE_IOC_SHM_REGISTER_FD > > below. > > + */ > > +struct tee_ioctl_shm_register_fd_data { > > + __s64 fd; > > + __u64 size; > > + __u32 flags; > > + __s32 id; > > +} __aligned(8); > > + > > +/** > > + * TEE_IOC_SHM_REGISTER_FD - register a shared memory from a file > > descriptor > > + * > > + * Returns a file descriptor on success or < 0 on failure > > + * > > + * The returned file descriptor refers to the shared memory object > > in kernel > > + * land. The shared memory is freed when the descriptor is closed. > > + */ > > +#define TEE_IOC_SHM_REGISTER_FD _IOWR(TEE_IOC_MAGIC, > > TEE_IOC_BASE + 8, \ > > + struct > > tee_ioctl_shm_register_fd_data) > > + > > /** > > * struct tee_ioctl_buf_data - Variable sized buffer > > * @buf_ptr: [in] A __user pointer to a buffer > > -- > > 2.25.0 > >
