From: Jason Gunthorpe <jgg@ziepe.ca>
To: fengchengwen <fengchengwen@huawei.com>
Cc: Zhiping Zhang <zhipingz@meta.com>,
Leon Romanovsky <leon@kernel.org>,
Michael Guralnik <michaelgur@nvidia.com>,
Sumit Semwal <sumit.semwal@linaro.org>,
Christian Konig <christian.koenig@amd.com>,
Alex Williamson <alex@shazbot.org>,
Bjorn Helgaas <bhelgaas@google.com>,
kvm@vger.kernel.org, linux-rdma@vger.kernel.org,
linux-pci@vger.kernel.org, dri-devel@lists.freedesktop.org
Subject: Re: [PATCH v12 0/4] vfio/dma-buf: add TPH support for peer-to-peer access
Date: Thu, 16 Jul 2026 11:47:08 -0300 [thread overview]
Message-ID: <20260716144708.GD210048@ziepe.ca> (raw)
In-Reply-To: <7dd5c995-a23c-4d3a-9ba0-7fc77972339f@huawei.com>
On Thu, Jul 16, 2026 at 09:07:35AM +0800, fengchengwen wrote:
> Because cross-Root-Port P2P traffic with ST does not affect the host, but
> merely the completer may experience some performance degradation because
> it lacks the TPH hint. In this case, I suggest adding restrictions in the
> uAPI.
I don't think this is complexity is worth doing for something that has
no functional impact.
There is no difference between supplying the TPH and not supplying it,
so may as well supply it.
Jason
next prev parent reply other threads:[~2026-07-16 14:47 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-07-15 20:39 [PATCH v12 0/4] vfio/dma-buf: add TPH support for peer-to-peer access Zhiping Zhang
2026-07-15 20:39 ` [PATCH v12 1/4] PCI/TPH: Add requester/completer type helpers Zhiping Zhang
2026-07-15 20:39 ` [PATCH v12 2/4] dma-buf: add optional get_pci_tph() callback Zhiping Zhang
2026-07-17 0:59 ` fengchengwen
2026-07-15 20:39 ` [PATCH v12 3/4] vfio/pci: implement get_pci_tph and DMA_BUF_TPH feature Zhiping Zhang
2026-07-17 0:36 ` fengchengwen
2026-07-15 20:39 ` [PATCH v12 4/4] RDMA/mlx5: get tph for p2p access when registering dma-buf mr Zhiping Zhang
2026-07-16 1:07 ` [PATCH v12 0/4] vfio/dma-buf: add TPH support for peer-to-peer access fengchengwen
2026-07-16 14:47 ` Jason Gunthorpe [this message]
2026-07-16 20:10 ` Zhiping Zhang
2026-07-16 20:08 ` Zhiping Zhang
2026-07-17 0:16 ` fengchengwen
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