From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794384662; b=ESKa1jjRpq+FwcRvwguYMaHb8Das1DuHPhD4CooiH9bCTlcerup+8TuZZyiXS0IWF2FX pYiZ+jM8uj500QN1UlymYWsbYzIZOeBHU4EjkA6YcXNtI8I86WP3QHo2xep/jejEBcM4l zxKbQE3S7bCVB1cw0AWwt1IVlV6TAGZJH36GBxnESAki8PB4bACRImSKLUDbavZJyrRSR na+JTMFLrD/XBRrejxY0GlYE3dp9ZX9kQgqa9clcAi4aGXdpCnPdQ5Fg98U6SiGLLC7Ut hldNwMsFgmu3dLT42i16AtEwGLThc5SKIuef0BNYLoIdVjE4MCcPJsr4GLVAU5xVbhQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794384662; h=Received:DKIM-Signature:Date:From:To:Cc:Subject:Message-ID: References:MIME-Version:Content-Type:Content-Disposition:In-Reply-To; bh=iOIeZv+xZF8BtnRxapOwV0sVr/Zsn6NcAiif3hZWdvQ=; b=AiU4y21+qYvnu29vpEIeBUFF4CgfBy9tqt1mz7LLtr/rRpaSDEemxEPa/z9TzSWM2SN3 NOhlq4LloaHBrC7A3Go43rIg4T3uapuRJfDrHz8AYMLsQ2CUmwTUOt7+OUVellnX2DOGw sxoQB/6Ufk3MSn/d6rzpY782IaQhTzHJvkGI9tWlHpJg7d9bJlfquIEWo0oJyL0i+tr18 O9U4+bG8lhZI69C9C1iL4xUfYk+No4fdlzCzKwDteiJD/3BXc4NhW+tU2FYr5bTqR35/C hpF5A1AKKuOGxWH4ThVk/wrEc2F6vZlU7iF15IuZ3c9yHMRxn0t2EyGiMh2VirdQHog== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=LOB+0xhE; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 90FD4606A321; Wed, 11 Nov 2026 08:11:02 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=LOB+0xhE Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9574A1F00A06; Wed, 11 Nov 2026 08:11:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794384662; bh=iOIeZv+xZF8BtnRxapOwV0sVr/Zsn6NcAiif3hZWdvQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=LOB+0xhETQ3vZMIg0adLD9hp5Rtnl/fj7End7gKSDSsjSaVydYMn5xYLPTU7iZneR vRnRQFGdvAvWnkZr0G08cmRHFKhyKXqJTQ5g5ZtxMPCrqY1WXiLoMWeuFMgDsjrEJD KEq+b2/yTwyP6qOyEaBZzGbtW24w1nxNCWc4EN6DyxXnc/FfMbJvmjk9aB6Ck9Qy5b kj6aMu6sybyBYUHrROe65d+AyNn7C5Ka458BaU85qKmdeSq/zr+FnjFuyJv3BZ5QUl lViwhs+HcyXu3CLBoEzUga7BXuEQu50LaDi1LPHxtMakqhDv4D44yUH8Wy7F52BabB i4jPIyOU6r0QQ== Date: Wed, 11 Nov 2026 10:10:57 +0200 From: Leon Romanovsky To: "Popov, Pavel E" Cc: Bjorn Helgaas , Logan Gunthorpe , Lukas Wunner , Jim Chow , Radu Rugina , Alexey Makhalov , Wei Liu , Michael Kelley , Nathan Ciobanu , "bcm-kernel-feedback-list@broadcom.com" , "virtualization@lists.linux.dev" , "linux-hyperv@vger.kernel.org" , "linux-pci@vger.kernel.org" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH v4 0/2] PCI/P2PDMA: Allow P2PDMA on Intel Xeon server CPUs Message-ID: <20261111081057.GP8635@unreal> References: <20261020173736.81755-1-pavel.e.popov@intel.com> X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Wed, Nov 11, 2026 at 03:48:07AM +0000, Popov, Pavel E wrote: > Hi Bjorn, > > Gentle ping on this series. Is this OK for v7.5? I would say no. An Intel employee was asked to clean up an Intel-created mess while upstreaming an Intel-specific patch. Peer-to-peer is a general concept, and the code should reflect that. It is reasonable to expect you to join the effort and help clean it up. Thanks > > Thanks, > Pavel > > > -----Original Message----- > > From: Popov, Pavel E > > Sent: Tuesday, October 20, 2026 10:38 AM > > To: Bjorn Helgaas ; Logan Gunthorpe > > > > Cc: Popov, Pavel E ; Leon Romanovsky > > ; Lukas Wunner ; Jim Chow > > ; Radu Rugina ; > > Alexey Makhalov ; Wei Liu > > ; Michael Kelley ; Nathan > > Ciobanu ; bcm-kernel-feedback- > > list@broadcom.com; virtualization@lists.linux.dev; linux- > > hyperv@vger.kernel.org; linux-pci@vger.kernel.org; linux- > > kernel@vger.kernel.org > > Subject: [PATCH v4 0/2] PCI/P2PDMA: Allow P2PDMA on Intel Xeon server > > CPUs > > > > VMware and Hyper-V expose passthrough devices to guest VMs without an > > explicit host bridge device. Consequently, host_bridge_whitelist() cannot > > automatically identify the underlying host bridge structure, causing Peer-to- > > Peer DMA (P2PDMA) requests to be rejected unless the device IDs are > > explicitly listed in pci_p2pdma_whitelist[]. To enable P2PDMA on Intel hosts, > > this series extends cpu_supports_p2pdma(), which so far covers AMD Zen and > > newer, with an explicit list of Intel Xeon server generations. > > > > Patch 1 moves the CONFIG_X86 #ifdef out of cpu_supports_p2pdma(). > > Patch 2 is the v3 patch rebased on it, with Logan's Reviewed-by carried over; > > the Xeon list and the check are unchanged. > > > > Changes in v4: > > - Add 1/2, moving the CONFIG_X86 #ifdef out of cpu_supports_p2pdma() > > (Logan Gunthorpe, Leon Romanovsky) > > - Keep the #ifdef around the asm/ includes, as these headers exist > > only on x86 (Bjorn Helgaas) > > > > Changes in v3: > > - Drop the hypervisor check and move the Xeon list into > > cpu_supports_p2pdma(), next to the AMD check, as suggested by Logan > > Gunthorpe and Leon Romanovsky [1] > > - Fold the VMware and Hyper-V patches into one, as the check no longer > > depends on the hypervisor > > > > Changes in v2: > > - Replace the Skylake-and-newer threshold with an explicit list of Intel > > Xeon server generations, from Skylake-SP to Diamond Rapids (Logan > > Gunthorpe) > > - Move the CONFIG_X86 #ifdef out of hypervisor_supports_p2pdma() > > (Logan Gunthorpe) > > - Rebased on current mainline > > > > [1] https://lore.kernel.org/r/20261016153147.GC219304@unreal > > > > v3: https://lore.kernel.org/r/20261020151305.65218-1- > > pavel.e.popov@intel.com > > v2: https://lore.kernel.org/r/20261016223402.19991-1- > > pavel.e.popov@intel.com > > v1: https://lore.kernel.org/r/20261009154034.82321-1- > > pavel.e.popov@intel.com > > > > Pavel Popov (2): > > PCI/P2PDMA: Move CONFIG_X86 #ifdef out of cpu_supports_p2pdma() > > PCI/P2PDMA: Allow P2PDMA on Intel Xeon server CPUs > > > > drivers/pci/p2pdma.c | 33 +++++++++++++++++++++++++++++++-- > > 1 file changed, 31 insertions(+), 2 deletions(-) > > > > > > base-commit: c03c1a14507dfaf8b856c2608f9ac216021fc222 > > -- > > 2.53.0 >