From patchwork Thu May 5 00:16:15 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefano Stabellini X-Patchwork-Id: 12838927 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 E52E8C433EF for ; Thu, 5 May 2022 00:16:53 +0000 (UTC) Received: from list by lists.xenproject.org with outflank-mailman.321169.542081 (Exim 4.92) (envelope-from ) id 1nmPAL-0007LX-2N; Thu, 05 May 2022 00:16:21 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 321169.542081; Thu, 05 May 2022 00:16:21 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1nmPAK-0007LQ-Uj; Thu, 05 May 2022 00:16:20 +0000 Received: by outflank-mailman (input) for mailman id 321169; Thu, 05 May 2022 00:16:20 +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 1nmPAJ-0007LG-VR for xen-devel@lists.xenproject.org; Thu, 05 May 2022 00:16:19 +0000 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by se1-gles-flk1.inumbo.com (Halon) with ESMTPS id 94e9c763-cc08-11ec-8fc4-03012f2f19d4; Thu, 05 May 2022 02:16:18 +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 dfw.source.kernel.org (Postfix) with ESMTPS id 982E061D4E; Thu, 5 May 2022 00:16:16 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 23E94C385B1; Thu, 5 May 2022 00:16:16 +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: 94e9c763-cc08-11ec-8fc4-03012f2f19d4 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1651709776; bh=a/fnNJ/bKKOG4tmQuObcdJZXY4wSKSDloZeQB+YRC8w=; h=Date:From:To:cc:Subject:From; b=ZaU/YGT0s/VxMgSGatTuRI/ua6haMOlNBLbWwfKsxq8u/M4yqS/TorElYIhQz3JvD 1LISqvh2EShuY9GL7GDCYU4UZRPqoR7o1RZsxT26gnwoV9rboW2+OUHNBRTOjIpzSf JRFW3HB753S+QqGkLNX5u7uFlXuiSGXBVzvrbPWmu4gEY+If1WKD29NpZ4aMiWfdqV D7wf9vdwefqQiq+wWJgpZy9nqRUiz6MuFtI45Dq7L0zk1ezjF1y5u90g8NlBXNkl51 /7WTbplxRE834Ry6YVuooBdi21VU8e/1xljep8WJToZvOkpplYD8WSaieFjhnymcpX 6uzangn0phfYg== Date: Wed, 4 May 2022 17:16:15 -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 v6 0/7] 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 "Adds starting the idle domain privileged". A important change in v5 is the usage of XS_CONNECTION_STATE_RECONNECTING to signal that the xenstore interface is not ready. 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 (4): xen/dt: of_property_read_string return -ENODATA when !length xen/arm: implement domU extended regions xen: introduce xen,enhanced dom0less property docs: document dom0less + PV drivers docs/features/dom0less.pandoc | 43 ++++- docs/misc/arm/device-tree/booting.txt | 18 ++ docs/misc/xen-command-line.pandoc | 9 +- tools/helpers/Makefile | 13 ++ tools/helpers/init-dom0less.c | 340 ++++++++++++++++++++++++++++++++++ tools/xenstore/xenstored_domain.c | 4 + xen/arch/arm/domain_build.c | 104 ++++++++++- xen/arch/arm/include/asm/kernel.h | 3 + xen/common/device_tree.c | 2 +- xen/common/event_channel.c | 2 +- xen/include/public/io/xs_wire.h | 2 +- xen/include/xen/device_tree.h | 3 + xen/include/xen/event.h | 3 + 13 files changed, 527 insertions(+), 19 deletions(-) create mode 100644 tools/helpers/init-dom0less.c