From mboxrd@z Thu Jan 1 00:00:00 1970 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 9D188C4332F for ; Fri, 16 Dec 2022 18:17:42 +0000 (UTC) Received: from list by lists.xenproject.org with outflank-mailman.464874.723403 (Exim 4.92) (envelope-from ) id 1p6FGp-0005Gk-Rn; Fri, 16 Dec 2022 18:17:19 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 464874.723403; Fri, 16 Dec 2022 18:17:19 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1p6FGp-0005Gd-OU; Fri, 16 Dec 2022 18:17:19 +0000 Received: by outflank-mailman (input) for mailman id 464874; Fri, 16 Dec 2022 18:17:18 +0000 Received: from se1-gles-sth1-in.inumbo.com ([159.253.27.254] helo=se1-gles-sth1.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1p6FGo-0005GW-SA for xen-devel@lists.xenproject.org; Fri, 16 Dec 2022 18:17:18 +0000 Received: from ams.source.kernel.org (ams.source.kernel.org [2604:1380:4601:e00::1]) by se1-gles-sth1.inumbo.com (Halon) with ESMTPS id df3e80ab-7d6d-11ed-91b6-6bf2151ebd3b; Fri, 16 Dec 2022 19:17:17 +0100 (CET) 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 8E6CDB81DE3; Fri, 16 Dec 2022 18:17:16 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 38D38C433D2; Fri, 16 Dec 2022 18:17:14 +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: df3e80ab-7d6d-11ed-91b6-6bf2151ebd3b DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1671214635; bh=KPm82mVTCr1jpMCDY0Q3mmkPxn/rELDRoWOUjMIBLM8=; h=Date:From:To:cc:Subject:In-Reply-To:References:From; b=JkS9kCPW0+iyxVHqf3QNMXZ0eQl6ZMT1MBPtenTPsvbz+HLQVypazm2ziSZE+z5Jb RlMy3McjNi8LgvFj0asWriL5tlR//9vFsElQoMa9VIuAhObN4abYdKkrgee5088k0V phGYo8/JRjBm99PVVS6ujF2Nr7tRYw/KN52ZsHUejtQzaOVTTTrZGPZxFNsi2q4zRv jRe1DDcT8JQQz3E1f7B1Y3p9OrO5fZc7TYU4GksW64vqmh4TqNv9CuVPY6eYEYEIix lOigiSBiOWcqkQuLDFrcro4e+5xXQknZp7SFJJuxlkhbzfNkyEQetcgceB7M0MKJzr JplNfaQe878lg== Date: Fri, 16 Dec 2022 10:17:12 -0800 (PST) From: Stefano Stabellini X-X-Sender: sstabellini@ubuntu-linux-20-04-desktop To: Michal Orzel cc: Stefano Stabellini , xen-devel@lists.xenproject.org, Julien Grall , Bertrand Marquis , Volodymyr Babchuk Subject: Re: [PATCH] xen/arm: Allow to set grant table related limits for dom0less domUs In-Reply-To: Message-ID: References: <20221214130833.543-1-michal.orzel@amd.com> User-Agent: Alpine 2.22 (DEB 394 2020-01-19) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII On Fri, 16 Dec 2022, Michal Orzel wrote: > On 15/12/2022 22:38, Stefano Stabellini wrote: > > On Wed, 14 Dec 2022, Michal Orzel wrote: > >> At the moment, for dom0less domUs, we do not have a way to specify > >> per domain grant table related limits (unlike when using xl), namely > >> max version, max number of grant frames, max number of maptrack frames. > >> This means that such domains always use the values specified by the Xen > >> command line parameters or their default values if unspecified. > >> > >> In order to have more control over dom0less domUs, introduce the > >> following device-tree properties that can be set under domUs nodes: > >> - max_grant_version to set the maximum grant table version the domain > >> is allowed to use, > >> - max_grant_frames to set the maximum number of grant frames the domain > >> is allowed to have, > >> - max_maptrack_frames to set the maximum number of grant maptrack frames > >> the domain is allowed to have. > >> > >> Update documentation accordingly. > >> > >> Note that the sanity checks regarding the passed values are already > >> there in grant_table_init() resulting in panic in case of errors, > >> therefore no need to repeat them in create_domUs(). > >> > >> Signed-off-by: Michal Orzel > >> --- > >> docs/misc/arm/device-tree/booting.txt | 21 +++++++++++++++++++++ > >> xen/arch/arm/domain_build.c | 11 ++++++++++- > >> 2 files changed, 31 insertions(+), 1 deletion(-) > >> > >> diff --git a/docs/misc/arm/device-tree/booting.txt b/docs/misc/arm/device-tree/booting.txt > >> index 87eaa3e25491..3879340b5e0a 100644 > >> --- a/docs/misc/arm/device-tree/booting.txt > >> +++ b/docs/misc/arm/device-tree/booting.txt > >> @@ -223,6 +223,27 @@ with the following properties: > >> the default size of domain P2M pool, i.e. 1MB per guest vCPU plus 4KB > >> per MB of guest RAM plus 512KB for guest extended regions. > >> > >> +- max_grant_version > >> + > >> + Optional. A 32-bit integer specifying the maximum grant table version > >> + the domain is allowed to use (valid values are 1 or 2). If this property > >> + is missing, the value specified by Xen command line parameter gnttab=max-ver > >> + (or its default value if unspecified, i.e. 1) is used. > >> + > >> +- max_grant_frames > >> + > >> + Optional. A 32-bit integer specifying the maximum number of grant frames > >> + the domain is allowed to have. If this property is missing, the value > >> + specified by Xen command line parameter gnttab_max_frames (or its default > >> + value if unspecified, i.e. 64) is used. > >> + > >> +- max_maptrack_frames > >> + > >> + Optional. A 32-bit integer specifying the maximum number of grant maptrack > >> + frames the domain is allowed to have. If this property is missing, the > >> + value specified by Xen command line parameter gnttab_max_maptrack_frames > >> + (or its default value if unspecified, i.e. 1024) is used. > >> + > >> Under the "xen,domain" compatible node, one or more sub-nodes are present > >> for the DomU kernel and ramdisk. > >> > >> diff --git a/xen/arch/arm/domain_build.c b/xen/arch/arm/domain_build.c > >> index bef5e905a73c..29b2f3e1faa2 100644 > >> --- a/xen/arch/arm/domain_build.c > >> +++ b/xen/arch/arm/domain_build.c > >> @@ -3871,7 +3871,7 @@ void __init create_domUs(void) > >> .max_maptrack_frames = -1, > >> .grant_opts = XEN_DOMCTL_GRANT_version(opt_gnttab_max_version), > >> }; > >> - unsigned int flags = 0U; > >> + unsigned int flags = 0U, val; > > > > val should be uint32_t > ok > > > > > > >> if ( !dt_device_is_compatible(node, "xen,domain") ) > >> continue; > >> @@ -3940,6 +3940,15 @@ void __init create_domUs(void) > >> d_cfg.cpupool_id = pool_id; > >> } > >> > >> + if ( dt_property_read_u32(node, "max_grant_version", &val) ) > >> + d_cfg.grant_opts = XEN_DOMCTL_GRANT_version(val); > >> + > >> + if ( dt_property_read_u32(node, "max_grant_frames", &val) ) > >> + d_cfg.max_grant_frames = val; > >> + > >> + if ( dt_property_read_u32(node, "max_maptrack_frames", &val) ) > >> + d_cfg.max_maptrack_frames = val; > > > > We need to be careful here because max_grant_frames and > > max_maptrack_frames are defined as int32_t (signed): > > > > int32_t max_grant_frames; > > int32_t max_maptrack_frames; > > > > I think we should have a check to make sure we don't cause an overflow. > > For instance: > > > > if ( val >= INT32_MAX ) { > > error; > > } > > d_cfg.max_grant_frames = val; > > Is following ok for you? > > if ( dt_property_read_u32(node, "max_grant_frames", &val) ) > { > if ( val > INT32_MAX ) > panic("max_grant_frames (%"PRIu32") overflow\n", val); > d_cfg.max_grant_frames = val; > } > > if ( dt_property_read_u32(node, "max_maptrack_frames", &val) ) > { > if ( val > INT32_MAX ) > panic("max_maptrack_frames (%"PRIu32") overflow\n", val); > d_cfg.max_maptrack_frames = val; > } Yes, looks good