From patchwork Fri Apr 1 00:38:41 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefano Stabellini X-Patchwork-Id: 12797810 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 4C243C433EF for ; Fri, 1 Apr 2022 00:38:56 +0000 (UTC) Received: from list by lists.xenproject.org with outflank-mailman.297153.506086 (Exim 4.92) (envelope-from ) id 1na5JN-0007p6-AC; Fri, 01 Apr 2022 00:38:45 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 297153.506086; Fri, 01 Apr 2022 00:38:45 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1na5JN-0007oz-7N; Fri, 01 Apr 2022 00:38:45 +0000 Received: by outflank-mailman (input) for mailman id 297153; Fri, 01 Apr 2022 00:38:44 +0000 Received: from se1-gles-flk1-in.inumbo.com ([94.247.172.50] helo=se1-gles-flk1.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1na5JM-0007ot-IX for xen-devel@lists.xenproject.org; Fri, 01 Apr 2022 00:38:44 +0000 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by se1-gles-flk1.inumbo.com (Halon) with ESMTPS id 155129bd-b154-11ec-8fbc-03012f2f19d4; Fri, 01 Apr 2022 02:38:43 +0200 (CEST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 3BCFCB822B4; Fri, 1 Apr 2022 00:38:43 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A2372C340EE; Fri, 1 Apr 2022 00:38:41 +0000 (UTC) X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: 155129bd-b154-11ec-8fbc-03012f2f19d4 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1648773522; bh=gD62MWAs68ym0DrdkBwu/7pHjmZ6s8wQ6W/cJ2XWfnY=; h=Date:From:To:cc:Subject:From; b=uNhelSy9DrEG93gfTjadm1VWBqYNdF/owDTro7EPqXZ6R4GxRsKC1bfShzu0CpKhP 9Z8QYK6Sw+fArxVlSpzrSnsUk/q8l5CB1pj/qMBA5aSBMOGeC26z36QqP+/+xjymx6 +0nHFhxDEyJEDxvyoUGqbYAvwjOoeEvAt7oQUIMkRED1MnMGSSdUdanZhhXtIN4Rqi yaU4XK4GVTPK2bbWay1hqTtBCGbDqt7YxEOFyoghS7n+dAdtB+WHNTVvLd84/RrA/h 7OmtvHO36mHm2LOYI9aeGTSNxVwtsM3oFhLZWiKuJSJ+aG284n/JJFN7QSUzBytKzp 2ZgoQjmbAE+Ug== Date: Thu, 31 Mar 2022 17:38:41 -0700 (PDT) From: Stefano Stabellini X-X-Sender: sstabellini@ubuntu-linux-20-04-desktop To: xen-devel@lists.xenproject.org cc: sstabellini@kernel.org, jgross@suse.com, Bertrand.Marquis@arm.com, julien@xen.org, Volodymyr_Babchuk@epam.com Subject: [PATCH v4 0/9] dom0less PV drivers Message-ID: User-Agent: Alpine 2.22 (DEB 394 2020-01-19) MIME-Version: 1.0 Hi all, Currently dom0less guests cannot use PV drivers because they don't have access to xenstore. Also, the hypervisor node in device tree is missing so they don't detect that they are running on Xen (thus, they don't try to enable PV interfaces.) This patch series enables dom0less guests (on ARM) to use PV drivers. Instead of initializing xenstore immediately at boot, dom0less guests get access to xenstore later. They delay the initialization until they receive a notification via the xenstore event channel (which is available at boot.) An example workflow is as follows: - all domains start in parallel, dom0less guests are immediately running - when dom0 is up and running, the init-dom0less application is called - dom0less guests receive the notification and initialize xenstore - now xl network-attach/disk-attach works as expected for dom0less domUs The patch series introduces a new dom0less device tree option "xen,enhanced" (in the Xen device tree) to specify whether PV interfaces should be enabled/disabled for the dom0less guest. This patch series is based on Daniel P. Smith's "Introduce XSM ability for domain privilege escalation". Cheers, Stefano Luca Miccio (3): xen/arm: configure dom0less domain for enabling xenstore after boot xenstored: send an evtchn notification on introduce_domain tools: add example application to initialize dom0less PV drivers Stefano Stabellini (6): xen/dt: dt_property_read_string should return -ENODATA on !length xen/arm: implement domU extended regions xen/arm: temporarily elevate idle_domain privileged during create_domUs xen: export evtchn_alloc_unbound xen: introduce xen,enhanced dom0less property docs: document dom0less + PV drivers docs/features/dom0less.pandoc | 43 ++++- docs/misc/arm/device-tree/booting.txt | 18 ++ tools/helpers/Makefile | 13 ++ tools/helpers/init-dom0less.c | 323 ++++++++++++++++++++++++++++++++++ tools/xenstore/xenstored_domain.c | 3 + xen/arch/arm/domain_build.c | 91 +++++++++- xen/arch/arm/include/asm/kernel.h | 3 + xen/common/device_tree.c | 2 +- xen/common/event_channel.c | 2 +- xen/include/xen/event.h | 3 + 10 files changed, 493 insertions(+), 8 deletions(-) create mode 100644 tools/helpers/init-dom0less.c