From: sagi@grimberg.me (Sagi Grimberg)
Subject: [RFC 7/7] NVMe: CMB on DMA-BUF
Date: Wed, 3 Aug 2016 13:02:07 +0300 [thread overview]
Message-ID: <0c87a1be-96e0-6aa2-920c-53203b5ad9dc@grimberg.me> (raw)
In-Reply-To: <20160801155206.GA23224@infradead.org>
Hey Christoph, Haggai,
>> Allocate a CMB region to user-space as a DMA-BUF object.
>
> NACK. Absolutely no way we're going to export a low-level device
> specific feature to userspace like that. If you want to DMA to
> the CMB do it from the kernel, and for that we'll need a proper
> block device level API.
I think that in this patch, Haggai was aiming to demonstrate the use
of dma_buf for peer2peer transactions with an RDMA device. I agree
that the CMB example can/should be exposed in the block device level,
but I also think we'd like to generalize the way we expose a bar space
of any peer device to another peer device.
How would you suggest we do that? I think Haggai's proposal is pretty
solid (considering the fact that the vast majority of RDMA applications
live in user-space).
prev parent reply other threads:[~2016-08-03 10:02 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-08-01 6:57 [RFC 0/7] RDMA subsystem DMA-BUF support Haggai Eran
2016-08-01 6:57 ` [RFC 1/7] IB/mlx5: Helper for posting work-requests on the UMR QP Haggai Eran
2016-08-01 6:57 ` [RFC 2/7] IB/mlx5: Support registration and invalidate operations " Haggai Eran
2016-08-01 6:57 ` [RFC 3/7] IB/core: Helpers for mapping DMA-BUF in MRs Haggai Eran
2016-08-01 6:57 ` [RFC 4/7] IB/uverbs: Add command to register a DMA-BUF fd Haggai Eran
2016-08-01 6:57 ` [RFC 5/7] IB/mlx5: Implement reg_user_dma_buf_mr Haggai Eran
2016-08-01 6:57 ` [RFC 6/7] NVMe: Use genalloc to allocate CMB regions Haggai Eran
2016-08-01 15:53 ` Christoph Hellwig
2016-08-01 16:20 ` Jon Derrick
2016-08-02 7:15 ` Haggai Eran
2016-08-02 6:48 ` Haggai Eran
2016-08-01 6:57 ` [RFC 7/7] NVMe: CMB on DMA-BUF Haggai Eran
2016-08-01 15:52 ` Christoph Hellwig
2016-08-02 7:10 ` Haggai Eran
2016-08-04 11:56 ` hch
2016-08-07 5:24 ` Haggai Eran
2016-08-03 10:02 ` Sagi Grimberg [this message]
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