From: Logan Gunthorpe <logang@deltatee.com>
To: Leon Romanovsky <leon@kernel.org>,
Bjorn Helgaas <bhelgaas@google.com>,
Jonathan Corbet <corbet@lwn.net>,
Shuah Khan <skhan@linuxfoundation.org>,
Alex Williamson <alex@shazbot.org>
Cc: linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-doc@vger.kernel.org
Subject: Re: [PATCH 08/13] PCI/P2PDMA: Honor ACS egress control vectors
Date: Tue, 4 Aug 2026 15:56:30 -0600 [thread overview]
Message-ID: <7d91cae7-1c57-4244-b019-51f374603124@deltatee.com> (raw)
In-Reply-To: <20260802-fix-p2p-acs-v1-8-a7c5eb64fff6@nvidia.com>
On 2026-08-02 09:09, Leon Romanovsky wrote:
> From: Leon Romanovsky <leonro@nvidia.com>
>
> An enabled Egress Control bit does not itself send a peer request
> upstream. PCIe r7.0, sec 6.12.3, table 6-11 makes the outcome depend on
> the Egress Control Vector bit for the target port: a clear bit routes the
> request directly regardless of P2P Request Redirect.
>
> Read the vector where the paths diverge below their common upstream port.
> Keep a clear vector bit on the direct path, subject to P2P Completion
> Redirect.
>
> A set bit with Request Redirect clear is an ACS Violation. ACS acts only
> on peer-to-peer Requests, so route it, and an indeterminate vector,
> through the host bridge.
>
> Fixes: 52916982af48 ("PCI/P2PDMA: Support peer-to-peer memory")
> Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
next prev parent reply other threads:[~2026-08-04 21:56 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-08-02 15:09 [PATCH 00/13] PCI/P2PDMA: Fix ACS egress control handling Leon Romanovsky
2026-08-02 15:09 ` [PATCH 01/13] PCI/P2PDMA: Safely terminate ACS redirect lists Leon Romanovsky
2026-08-04 19:49 ` Logan Gunthorpe
2026-08-02 15:09 ` [PATCH 02/13] PCI/P2PDMA: Report ACS ports when the paths share no upstream bridge Leon Romanovsky
2026-08-04 19:52 ` Logan Gunthorpe
2026-08-02 15:09 ` [PATCH 03/13] PCI/P2PDMA: Document the Address Type assumption Leon Romanovsky
2026-08-04 19:55 ` Logan Gunthorpe
2026-08-02 15:09 ` [PATCH 04/13] PCI: Account for Direct Translated P2P in ACS isolation checks Leon Romanovsky
2026-08-04 20:03 ` Logan Gunthorpe
2026-08-02 15:09 ` [PATCH 05/13] PCI: Add ACS egress control vector accessor Leon Romanovsky
2026-08-04 21:55 ` Logan Gunthorpe
2026-08-02 15:09 ` [PATCH 06/13] PCI: Account for ACS egress control in isolation checks Leon Romanovsky
2026-08-04 21:55 ` Logan Gunthorpe
2026-08-02 15:09 ` [PATCH 07/13] PCI/P2PDMA: Derive peer-to-peer routing from ACS control bits Leon Romanovsky
2026-08-04 21:55 ` Logan Gunthorpe
2026-08-04 21:58 ` Logan Gunthorpe
2026-08-02 15:09 ` [PATCH 08/13] PCI/P2PDMA: Honor ACS egress control vectors Leon Romanovsky
2026-08-04 21:56 ` Logan Gunthorpe [this message]
2026-08-02 15:09 ` [PATCH 09/13] PCI/P2PDMA: Document ACS egress control handling Leon Romanovsky
2026-08-04 22:01 ` Logan Gunthorpe
2026-08-05 9:02 ` Leon Romanovsky
2026-08-02 15:09 ` [PATCH 10/13] PCI/P2PDMA: Extract pure ACS routing decision helpers Leon Romanovsky
2026-08-04 22:07 ` Logan Gunthorpe
2026-08-05 9:06 ` Leon Romanovsky
2026-08-02 15:09 ` [PATCH 11/13] PCI/P2PDMA: Add KUnit tests for ACS routing decisions Leon Romanovsky
2026-08-04 22:37 ` Logan Gunthorpe
2026-08-02 15:09 ` [PATCH 12/13] PCI/P2PDMA: Add KUnit coverage for the ACS P2P routing walk Leon Romanovsky
2026-08-04 22:37 ` Logan Gunthorpe
2026-08-02 15:09 ` [PATCH 13/13] PCI: Add KUnit coverage for ACS isolation checks Leon Romanovsky
2026-08-04 22:38 ` Logan Gunthorpe
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