From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 3CBD9202F70; Sun, 30 Aug 2026 09:20:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788081638; cv=none; b=EeFG/wK46Gkisj3iqK2z+y4C1gfVVO/qzSTb9IqNehK03daIr55d+ImVyM5REooZvSSQ9ckbmyr+VHiYDNRqGyQxX64sVIH4nEgH/mv723Yp916KZw04D72J3hOcNh9puoM0ie5in/e2YakQKJzAICnafJB/M03UtY+EkEhNLqQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788081638; c=relaxed/simple; bh=QncR1qUGWy+W3Pof34ojKH3irxh4p5y/PlIPK7O08j0=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=dHrOKnTjnKwobJmGJ85vHM1Q3nwSp3k1QV3uTIjpsLD20zIs8o021Nd7LaLhlWkWyaOl1rW3NLQPFfFH0DGAlTvCrHjHNtHLf0WmnvIceaSIbg8dxjRJz0hULkbZ94VypNEBF4DhW9EZV7b2sSlNiSt7kz6qldhnFcEk2OwjzfI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=YqUd2bEX; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="YqUd2bEX" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 443131F000E9; Sun, 30 Aug 2026 09:20:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1788081636; bh=2r5ATwh6+YU45/CW5aqnh5QdexD448pFy1trWFGs/4I=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=YqUd2bEX4pBT0B78Scu66Uf1Ul20NzXAa6UUO7GTm2+NFPX8nTivh7uB+CYXIbrcq NQRHi4GNBXk4/NXIyfjth1AC0okm6YHtqMYYnz/obpZ5lDZKQ9JEEXHNkz9BFBIWng hu6MNhR1xW056ea73NSYrnfXC+5uFdWmVRyZGmbTivn1aLz3s+cyWpLk6S38V7v8PW MNQkeVHZR0QoXqnLa2ftVUSmtdr55qVbyTLNDo95R7URlD7+D+KO8tqxYwXvNpwcF4 zqgS8LVIY6nfJGmEGHAlp4z74dCIj3sWn1SHc3nNphMnhR8clxnKROHEnNnrYocsbi 8IXp1kVh8ZtuA== Date: Sun, 30 Aug 2026 12:20:33 +0300 From: Leon Romanovsky To: Jason Gunthorpe Cc: Bjorn Helgaas , Logan Gunthorpe , Chaitanya Kulkarni , Greg Kroah-Hartman , Jens Axboe , Alex Williamson , Ankit Agrawal , Jason Gunthorpe , Jonathan Corbet , Shuah Khan , "Joerg Roedel (AMD)" , Will Deacon , Robin Murphy , linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, iommu@lists.linux.dev, Tushar Dave Subject: Re: [PATCH v4 10/18] PCI: Account for ACS egress control in isolation checks Message-ID: <20260830092033.GE24140@unreal> References: <20260821-fix-p2p-acs-v4-0-v4-0-94426b96de73@nvidia.com> <20260821-fix-p2p-acs-v4-0-v4-10-94426b96de73@nvidia.com> <178761377056.3197084.2573998749847027711.b4-review@b4> Precedence: bulk X-Mailing-List: linux-pci@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <178761377056.3197084.2573998749847027711.b4-review@b4> On Mon, Aug 24, 2026 at 08:22:50PM -0300, Jason Gunthorpe wrote: > > pci_acs_enabled() treats P2P Request Redirect as effective whenever its > > control bit is set. PCIe r7.0, sec 6.12.3, table 6-11 lets an enabled > > Egress Control Vector override it: a clear vector bit routes the request > > directly. > > This may well all be correct, but I'd prefer not to touch grouping in > this series working on p2pdma.. The grouping logic is already not > doing a good job with the spec and we can't change it because it > creates regression. The longer we wait, the harder it will be to address this deviation from the PCI specification. Thanks > > -- > Jason