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=1794445097; b=s2vKOLyGuFM+KvVu+c+ivaFwnjQ/bQK6ibiVew0TjjicYj3eD9bbpDP/+im+jWva/0NY mAYeqWTapL/wLWG4ESNAnaUn+wab2JTJuNEfG0zxecFmuVQZGAILdTIGbF8ApYlF03Y5V h9JKmOQuqfk9qxfVqRu0Aty9oaAC7V3rYjcl0WUWjXhnXlu5gkR0YsWwpMgOaCzwE7ZfW yYGwu6r2gQenMzKSV5x1sByW0Q4w9YNg897Zg+0actsM9FVddNpW5kmgFcwFmgYlDTs4C nUHRDJCcJWlDmxKkF4Q19XoosczQ3zK/ZgS5iROmQmbrIY8zlswhQMwfuKhYCSDWJwg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794445097; h=Received:DKIM-Signature:Message-ID:From:Subject:Reply-To:To:Cc: In-Reply-To:References:Content-Type:Content-Transfer-Encoding:Date; bh=hHrQivxW5T3a7oRj7V0wGHKLLWWqowcM5Cnk8v+7W0w=; b=GjuHKPg6T/OKezs6RWoBQjGyCA9zu+WNHPlOGTvXKvjsrlNxNNPoi2AxM07E/mhO0iXm KuuqDu8R0ktOzUGlrpuk8L5ZMzbeLamRFb1zIBn2DSr5nj0jckcGkGzY/NI4CxFVPaqm/ VbshfM0t0niV5sQ5ZYaTca4Pu1BzplPPr37l8fCqn308B7YsM603Z06pe9DlZfcXYVrUV yqxW325rRI82aXmthG5xCtRxhQ2+dygMF6RzLFRDqDJH7NjzIUV1MC6g0XSva/Snh5xOm e6UGoUqgKDgeAnHaY7bjN2PgsA9826+nq3k+TeYG1+KnOVfZ8q0RjnvtsMuTRhpvvZw== 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=BYK8TyHX; 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 54FF0606A321; Thu, 12 Nov 2026 00:58:17 +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=BYK8TyHX Received: by smtp.kernel.org (Postfix) with ESMTPSA id A492A1F00A05; Thu, 12 Nov 2026 00:58:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794445096; bh=hHrQivxW5T3a7oRj7V0wGHKLLWWqowcM5Cnk8v+7W0w=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=BYK8TyHXz8WTPSuxa7BJr2GSOOoh5RGdQHrTAboAansFbS76FMtSHDKuxvdFhtpb5 MhmBsSyQgkbtcUQiGqP2lq5NnwctPyZyruAP6MjZQYT/MgY+BL3iT0JJZ3v92Feydc bCB5shc09V0m4KC75kL9sacPuHk8UL/iY8fbgU0xgF6Omw6juk7LUG1UncY1c7vq+N TP8NwXXFaTQAq/N3sukGn0m3nBivHQpVN3Fv76b3ekBekRzmyBTT8942H/iGCVadYK Wp9pzL4khqY+h6hL3rUT5+ux2IIlxR5FpiDx5cuO+8NPUQfrWSi0oXCOcX9DB4xe8k 2PWGUummKMEkA== Message-ID: From: sashiko-bot@kernel.org Subject: Re: [PATCH v5 3/3] PCI/P2PDMA: Allow P2PDMA on Intel Xeon server CPUs Reply-To: sashiko-reviews@lists.linux.dev To: "Pavel Popov" Cc: virtualization@lists.linux.dev, linux-pci@vger.kernel.org, "Michael S. Tsirkin" , "Eugenio Perez" In-Reply-To: <20261111234439.4098-4-pavel.e.popov@intel.com> References: <20261111234439.4098-1-pavel.e.popov@intel.com> <20261111234439.4098-4-pavel.e.popov@intel.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Thu, 12 Nov 2026 00:58:16 +0000 X-Mailing-List: virtualization@lists.linux.dev List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list > Peer-to-Peer DMA (P2PDMA) between two devices requires either a shared > upstream bridge or a host bridge matching pci_p2pdma_whitelist[]. In > VMware guests, passthrough devices appear directly on virtual root > buses without host bridge devices. In Hyper-V guests, each passthrough > device appears in a PCI domain of its own without a host bridge > device. Consequently, P2PDMA checks evaluate endpoint Device IDs > against the host bridge whitelist, causing P2PDMA requests to fail > regardless of host support. >=20 > This affects discrete devices such as GPUs, NICs and NVMe drives. >=20 > Add an explicit list of the Intel Xeon server generations from > Skylake-SP to Diamond Rapids to cpu_supports_p2pdma(). These are the > CPUs whose host bridges are in pci_p2pdma_whitelist[] without > restrictions. AMD Zen and newer are already covered by > cpu_supports_p2pdma(), so only Intel entries are needed. >=20 > Tested with the Intel Level Zero P2P benchmark (ze_peer) on Arc Pro B60 > cards in a Linux guest on VMware ESXi 9.0 (Emerald Rapids host). >=20 > Signed-off-by: Pavel Popov Sashiko has reviewed this patch and found no issues. --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20261111234439.4098= -1-pavel.e.popov@intel.com?part=3D3