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 8C19E471CE0; Wed, 14 Oct 2026 06:46:58 +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=1791960420; cv=none; b=YCSwjii86mknYlhAAFAiSKMxyWZxRLbN62dOcvN7Ei+/72ZCWyP/Gig+g+fFlYoelBf3tEdDTlkNvIlus5fr+Rcn4k0TN/jnFyk/ZcKsVWH0tCoDp8CVSC7z86qKVZY3Qs77kAk40XQ8P2dqIp4BYApDV7oX7m/ZWs3qWNkhvaE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791960420; c=relaxed/simple; bh=mSnnriOkSKlnUk+6fo/Kq1ixneeAL4WZQRBSJOIW3qI=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=ItzHLXwsaiaaObExfgrhPXk1ROObty6mb9bOWiPZiSAt0QevAACe7hHujF2ZG/pa6jq4cPnmrM1SgtjU7C5qulU60JXPCfpX1oEZBV6YGxKK7Xfl8JnXLcOqy5Jl17Milno+xWvUrtCQrbTNPhdJTqNfB+VvzSl12BY5ujDvRw4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=gFTX6Ntx; 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="gFTX6Ntx" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 486491F000FF; Wed, 14 Oct 2026 06:46:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1791960417; bh=j8H0NoEXZnVe8rGJVifKPpZGEuefBe+Pz5xO0QIVr0I=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=gFTX6Ntxaax3HpDdnJEqgzvZFPRgjas53WK98vDIqzhm1UPXFlZfgiJLI+UFizKym mzRe1ELAzr/6yp6GwQycX4feklE7pujtlHPXnezGoCTQ0GA5E/j6MMTXpRjkEPJCnD WAWUvtH+z9KtQaBxwt2Y1dkoUO3thjterApS1b0UpngvYErooh4lTKMtM4zx9VxQ3/ Hp9pcaMzrbSTogPgKIz5XiWtSNDze4uoyXUHHJtBxzO4isSFFHGOtL1KUtdanEeeBw hVWB+3MaPWbukUdvhIJ2jgupe4/cJIk5mtbJ82xxyJ/IQ4YRF2xY2RQubi7/vpLqiP iotkrBwrhKqFA== Date: Wed, 14 Oct 2026 09:46:53 +0300 From: Leon Romanovsky To: sashiko-reviews@lists.linux.dev Cc: linux-pci@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-rdma@vger.kernel.org, kvm@vger.kernel.org, media-ci@linuxtv.org Subject: Re: [PATCH v11 09/19] PCI/P2PDMA: Route Relaxed Ordering Completions directly Message-ID: <20261014064653.GT219304@unreal> References: <20261013-fix-p2p-acs-v4-0-v11-0-72cf8c96e617@nvidia.com> <20261013-fix-p2p-acs-v4-0-v11-9-72cf8c96e617@nvidia.com> Precedence: bulk X-Mailing-List: kvm@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: On Tue, Oct 13, 2026 at 02:37:38PM +0000, sashiko-bot@kernel.org wrote: > Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider: > - [Low] pci/p2pdma: false positive warning if Relaxed Ordering route succeeds > -- > > commit e6e15dbbdb2b5d6dee258b1197f71025a221015f > Author: Leon Romanovsky > > PCI/P2PDMA: Route Relaxed Ordering Completions directly > > ACS P2P Completion Redirect leaves Completions carrying Relaxed Ordering > alone, per PCIe r7.0 sec 6.12.1.1. A Completion copies that attribute from > its Request, so a client setting it on Non-Posted Requests need not use the > host bridge solely because Completion Redirect is enabled. > > Route Completions directly for PCI_P2PDMA_TLP_RELAXED_CPL unless a device > quirk redirects them or the Completer lacks an internal route to its > sibling. Neither restriction promises a Relaxed Ordering exception. No > caller selects these classes yet. > > > diff --git a/drivers/pci/p2pdma.c b/drivers/pci/p2pdma.c > > index 9d416329aa4b8..785e4668a2af5 100644 > > --- a/drivers/pci/p2pdma.c > > +++ b/drivers/pci/p2pdma.c > > @@ -580,11 +580,15 @@ pci_acs_p2pdma_request(u16 ctrl, unsigned int tlp_flags) > > /* > > * Decide how a peer-to-peer Completion at an ACS-capable ingress port routes. > > * PCIe r7.0 sec 6.12.1.1: no ACS control other than P2P Completion Redirect > > - * affects a Completion. > > + * affects a Completion, and that one leaves Completions carrying the Relaxed > > + * Ordering attribute alone. > > */ > > static enum pci_acs_p2pdma_state > > pci_acs_p2pdma_completion(u16 ctrl, unsigned int tlp_flags) > > { > > + if (tlp_flags & PCI_P2PDMA_TLP_RELAXED_CPL) > > + return PCI_ACS_P2PDMA_DIRECT; > > + > > [Severity: Low] > Now that Relaxed Ordering completions can route directly while strict ordering > might still redirect, does this cause a false positive warning in > calc_map_type_and_dist() in drivers/pci/p2pdma.c? There are no in-kernel callers that selects RO. In current code, this flow is impossible. Thanks