From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from ale.deltatee.com (ale.deltatee.com [204.191.154.188]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E1F422931F8; Fri, 18 Sep 2026 19:40:13 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=204.191.154.188 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789760415; cv=none; b=LI46YPoahelWrWmba8QHofrdepQyJjLcxFUKq8rfx3WZBdnPO2iO59sy7IWVdx948M050ocMP1PI0JKTkl1DTIeP0IpiSXFm6BzkGAYgceOMOoBTQNUtIBGQOLVzJXXrMK/IKUb75e7DTlft/I97nVEpHLo917qJWDoUC0WtqHc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789760415; c=relaxed/simple; bh=Kk3ar4q45siHy1y0rPnYfhOrE+vVoxmAnZK8w5kMOiw=; h=Message-ID:Date:MIME-Version:To:Cc:References:From:In-Reply-To: Content-Type:Subject; b=OTFQ6+aomGsXsOr0YIeRK9gExMd6+vr68CB3LyY8kbzuULJy/YDm0jOZIax1tqlhA1Nu/6K7OH3lsAGmBcXnzTPrkXxKbHVxNW4Y0WBMIWIiqvERF8SD4wfaApwdXfaTeEe+LPjSKKM+o0P9DKa9zpCH1dhriPa5A7bT7BohzLI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=deltatee.com; spf=pass smtp.mailfrom=deltatee.com; dkim=pass (2048-bit key) header.d=deltatee.com header.i=@deltatee.com header.b=p1hFKb1F; arc=none smtp.client-ip=204.191.154.188 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=deltatee.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=deltatee.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=deltatee.com header.i=@deltatee.com header.b="p1hFKb1F" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=deltatee.com; s=20200525; h=Subject:In-Reply-To:From:References:Cc:To: MIME-Version:Date:Message-ID:content-disposition; bh=lQAIrUFP3+D+tD4U17DzHrKkOc11Ho5y+ORRcF4NPXs=; b=p1hFKb1F/D9iIDg6hNHtr8GiM2 l37aQ39NUCI6IRV6cw9gskBQm2rzWzmoVGB1A1sSt6dz5QZVE29rnly2O4sra+jAVtX5GubBbhzIT estioaTW7b42lemwzxUqTkaexKwqWBQXacYsSjVZzNvKbOFT+MjWkLM0OirZSxU2f7sT+NKmqaUfV o2SyHTECs+cKETwfqStVBNeQngTXT/DtkXdqEV9Mma6d2VcU0eUSuvkbsuX6aqp80gMFjKciNXgwC YI36SyWZbHBozXXE9/fXLmwHKXHr3dGHRBoTkxESWTCrljgEUe7uToA9S6ifHB5P/eblW6xIUFZVM uH56LcFg==; Received: from guinness.priv.deltatee.com ([172.16.1.162]) by ale.deltatee.com with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 (Exim 4.98.2) (envelope-from ) id 1x7eRN-0000000CrxC-0gtG; Fri, 18 Sep 2026 13:40:10 -0600 Message-ID: <19bee27e-17d7-4b67-b796-ca5bb44e8de7@deltatee.com> Date: Fri, 18 Sep 2026 13:39:55 -0600 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird To: Leon Romanovsky , Bjorn Helgaas , Chaitanya Kulkarni , Greg Kroah-Hartman , Jens Axboe , Alex Williamson , Ankit Agrawal , Jason Gunthorpe , Jonathan Corbet , Shuah Khan , "Joerg Roedel (AMD)" , Will Deacon , Robin Murphy , Randy Dunlap , Sumit Semwal , =?UTF-8?Q?Christian_K=C3=B6nig?= Cc: linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, iommu@lists.linux.dev, Tushar Dave , linux-media@vger.kernel.org, dri-devel@lists.freedesktop.org, linaro-mm-sig@lists.linaro.org, linux-rdma@vger.kernel.org, kvm@vger.kernel.org References: <20260914-fix-p2p-acs-v4-0-v6-0-5ef07ec9ef06@nvidia.com> <20260914-fix-p2p-acs-v4-0-v6-3-5ef07ec9ef06@nvidia.com> Content-Language: en-CA From: Logan Gunthorpe In-Reply-To: <20260914-fix-p2p-acs-v4-0-v6-3-5ef07ec9ef06@nvidia.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-SA-Exim-Connect-IP: 172.16.1.162 X-SA-Exim-Rcpt-To: leon@kernel.org, bhelgaas@google.com, kch@nvidia.com, gregkh@linuxfoundation.org, axboe@kernel.dk, alex@shazbot.org, ankita@nvidia.com, jgg@ziepe.ca, corbet@lwn.net, skhan@linuxfoundation.org, joro@8bytes.org, will@kernel.org, robin.murphy@arm.com, rdunlap@infradead.org, sumit.semwal@linaro.org, christian.koenig@amd.com, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, iommu@lists.linux.dev, tdave@nvidia.com, linux-media@vger.kernel.org, dri-devel@lists.freedesktop.org, linaro-mm-sig@lists.linaro.org, linux-rdma@vger.kernel.org, kvm@vger.kernel.org X-SA-Exim-Mail-From: logang@deltatee.com X-Spam-Level: Subject: Re: [PATCH v6 03/18] PCI/P2PDMA: Derive routing from directional ACS controls X-SA-Exim-Version: 4.2.1 (built Sun, 23 Feb 2025 07:57:16 +0000) X-SA-Exim-Scanned: Yes (on ale.deltatee.com) On 2026-09-14 05:22, Leon Romanovsky wrote: > From: Leon Romanovsky > > pci_bridge_has_acs_redir() treats Request and Completion Redirect as > interchangeable. On asymmetric fabrics, a control for only the reverse TLP > direction can unnecessarily force P2PDMA through the host bridge. > > Evaluate Request Redirect for client Requests and Completion Redirect for > provider read Completions. Continue treating enabled Egress Control > conservatively as a Request redirect. > > Fixes: 52916982af48 ("PCI/P2PDMA: Support peer-to-peer memory") > Signed-off-by: Leon Romanovsky Core patch seems fine, minus one minor point below: Reviewed-by: Logan Gunthorpe > @@ -1132,10 +1173,10 @@ EXPORT_SYMBOL_GPL(pci_p2pmem_publish); > /** > * pci_p2pdma_map_type - Determine the mapping type for P2PDMA transfers > * @provider: P2PDMA provider structure > - * @dev: Target device for the transfer > + * @dev: Client device that initiates the transfer > * > * Determines how peer-to-peer DMA transfers should be mapped between > - * the provider and the target device. The mapping type indicates whether > + * the provider and the client device. The mapping type indicates whether > * the transfer can be done directly through PCI switches or must go > * through the host bridge. > */ > This hunk does not seem like it belongs in this patch.