From: Jason Gunthorpe <jgg@ziepe.ca>
To: "Xiong, Jianxin" <jianxin.xiong@intel.com>
Cc: "linux-rdma@vger.kernel.org" <linux-rdma@vger.kernel.org>,
"dri-devel@lists.freedesktop.org"
<dri-devel@lists.freedesktop.org>,
Doug Ledford <dledford@redhat.com>,
Leon Romanovsky <leon@kernel.org>,
Sumit Semwal <sumit.semwal@linaro.org>,
Christian Koenig <christian.koenig@amd.com>,
"Vetter, Daniel" <daniel.vetter@intel.com>
Subject: Re: [PATCH v8 1/5] RDMA/umem: Support importing dma-buf as user memory region
Date: Fri, 6 Nov 2020 12:39:53 -0400 [thread overview]
Message-ID: <20201106163953.GR36674@ziepe.ca> (raw)
In-Reply-To: <MW3PR11MB45552DC0851F4490B2450EDFE5ED0@MW3PR11MB4555.namprd11.prod.outlook.com>
On Fri, Nov 06, 2020 at 04:34:07PM +0000, Xiong, Jianxin wrote:
> > The user could specify a length that is beyond the dma buf, can
> > the dma buf length be checked during get?
>
> In order to check the length, the buffer needs to be mapped. That can be done.
Do DMA bufs even have definitate immutable lengths? Going to be a
probelm if they can shrink
> > Also page_size can be 0 because iova is not OK. iova should be
> > checked for alignment during get as well:
> >
> > iova & (PAGE_SIZE-1) == umem->addr & (PAGE_SIZE-1)
>
> If ib_umem_dmabuf_map_pages is called during get this error is automatically caught.
The ib_umem_find_best_pgsz() checks this equation, yes.
So you'd map the sgl before allocating the mkey? This then checks the
length and iova?
Jason
next prev parent reply other threads:[~2020-11-06 16:39 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-05 22:48 [PATCH v8 0/5] RDMA: Add dma-buf support Jianxin Xiong
2020-11-05 22:48 ` [PATCH v8 1/5] RDMA/umem: Support importing dma-buf as user memory region Jianxin Xiong
2020-11-06 0:08 ` Jason Gunthorpe
2020-11-06 16:34 ` Xiong, Jianxin
2020-11-06 16:39 ` Jason Gunthorpe [this message]
2020-11-06 17:01 ` Xiong, Jianxin
2020-11-10 14:14 ` Daniel Vetter
2020-11-10 14:27 ` Jason Gunthorpe
2020-11-10 14:44 ` Daniel Vetter
2020-11-10 17:23 ` Xiong, Jianxin
2020-11-05 22:48 ` [PATCH v8 2/5] RDMA/core: Add device method for registering dma-buf based " Jianxin Xiong
2020-11-05 22:48 ` [PATCH v8 3/5] RDMA/uverbs: Add uverbs command for dma-buf based MR registration Jianxin Xiong
2020-11-06 0:13 ` Jason Gunthorpe
2020-11-06 16:20 ` Xiong, Jianxin
2020-11-06 16:37 ` Jason Gunthorpe
2020-11-05 22:48 ` [PATCH v8 4/5] RDMA/mlx5: Support dma-buf based userspace memory region Jianxin Xiong
2020-11-06 0:25 ` Jason Gunthorpe
2020-11-06 1:11 ` Xiong, Jianxin
2020-11-06 12:48 ` Jason Gunthorpe
2020-11-06 16:10 ` Xiong, Jianxin
2020-11-05 22:48 ` [PATCH v8 5/5] dma-buf: Reject attach request from importers that use dma_virt_ops Jianxin Xiong
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