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 C3F98C38145 for ; Tue, 6 Sep 2022 06:27:47 +0000 (UTC) Received: from list by lists.xenproject.org with outflank-mailman.399370.640512 (Exim 4.92) (envelope-from ) id 1oVS3R-0005DO-Ct; Tue, 06 Sep 2022 06:27:25 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 399370.640512; Tue, 06 Sep 2022 06:27:25 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1oVS3R-0005DH-AA; Tue, 06 Sep 2022 06:27:25 +0000 Received: by outflank-mailman (input) for mailman id 399370; Tue, 06 Sep 2022 06:27:24 +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 1oVS3P-0005DB-RV for xen-devel@lists.xenproject.org; Tue, 06 Sep 2022 06:27:24 +0000 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by se1-gles-sth1.inumbo.com (Halon) with ESMTPS id f6b32866-2dac-11ed-a016-b9edf5238543; Tue, 06 Sep 2022 08:27:21 +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 706B4B81619; Tue, 6 Sep 2022 06:27:21 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0EEBEC433D6; Tue, 6 Sep 2022 06:27:20 +0000 (UTC) Received: from sofa.misterjones.org ([185.219.108.64] helo=why.misterjones.org) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.95) (envelope-from ) id 1oVS3J-008ET7-P2; Tue, 06 Sep 2022 07:27:17 +0100 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: f6b32866-2dac-11ed-a016-b9edf5238543 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1662445640; bh=igFNa4rbBoErHv0XWpIkATD1jfwiBEbsi335mfFwe7w=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=PqjCFCDYkb6Dw/p5YNwrg9LJVAoM2erCwaEplExiJbiagUZnruBpROt79ONc/S5ZT UTsZR0ggiR+8kpYWP182LJE8tEjGUlVQyl1Ln53bU1e62Sl5roUdU0snv5TkIsBggI cHgBlqXCdHBjjA/7tFTsJJdZmIUPiKAzpXTKw2a0uGhXSQmYRvxgRdY0lby0+dpRkh Hy6xvm/E6Cjwzcbek8ljv+ThC52mBNyZLPPtgx/RH8BXS/gqkOgt9kaGGPxvy91GYP eToDuKt30DfcZtX20s5zvCfGjo1oOIv621+N5+E7dlKs0OfheV6Mk+qneNxTE2v5Uw FYP2qPsAjavEw== Date: Tue, 06 Sep 2022 07:27:17 +0100 Message-ID: <87r10puiey.wl-maz@kernel.org> From: Marc Zyngier To: Leo Yan Cc: Julien Grall , Ard Biesheuvel , Jan Beulich , Bertrand Marquis , Rahul Singh , Peter Griffin , xen-devel , Julien Grall , Mathieu Poirier Subject: Re: [PATCH] xen/arm: acpi: Support memory reserve configuration table In-Reply-To: References: <99e460f1-ca5f-b520-69e0-b250915fd591@xen.org> <871qtcsacd.wl-maz@kernel.org> <12a8c169-55aa-5e9f-19f8-acd77ea2a8fe@xen.org> <52f24132-ba2b-d4ab-ebd0-613f673b5658@xen.org> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI-EPG/1.14.7 (Harue) FLIM-LB/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL-LB/10.8 EasyPG/1.0.0 Emacs/27.1 (x86_64-pc-linux-gnu) MULE/6.0 (HANACHIRUSATO) MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") Content-Type: text/plain; charset=US-ASCII X-SA-Exim-Connect-IP: 185.219.108.64 X-SA-Exim-Rcpt-To: leo.yan@linaro.org, julien@xen.org, ardb@kernel.org, jbeulich@suse.com, Bertrand.Marquis@arm.com, Rahul.Singh@arm.com, peter.griffin@linaro.org, xen-devel@lists.xenproject.org, jgrall@amazon.com, mathieu.poirier@linaro.org X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false On Tue, 06 Sep 2022 03:52:37 +0100, Leo Yan wrote: > > On Thu, Aug 25, 2022 at 10:40:41PM +0800, Leo Yan wrote: > > [...] > > > > > But here I still cannot create the concept that how GIC RD tables play > > > > roles to support the para virtualization or passthrough mode. > > > > > > I am not sure what you are actually asking. The pending tables are just > > > memory you give to the GICv3 to record the state of the interrupts. > > > > For more specific, Xen has its own RD pending table, and we can use > > this pending table to set state for SGI/PPI/LPI for a specific CPU > > interface. Xen works as hypervisor, it saves and restores the pending > > table according to switched in VM context, right? > > > > On the other hand, what's the purpose for Linux kernel's GIC RD > > pending table? Is it only used for nested virtulisation? I mean if > > Linux kernel's GIC RD pending table is not used for the drivers in > > Dom0 or DomU, then it's useless to pass it from the primary kernel to > > secondary kernel; as result, we don't need to reserve the persistent > > memory for the pending table in this case. > > I don't receive further confirmation from Marc, anyway, I tried to cook > a kernel patch to mute the kernel oops [1]. What sort of confirmation do you expect from me? None of what you write above make much sense in the face of the architecture. > Hope this is not too arbitrary and we can move forward a bit. > > Thanks, > Leo > > [1] https://lore.kernel.org/lkml/20220906024040.503764-1-leo.yan@linaro.org/T/#u I'm totally baffled by the fact you're trying to add some extra hacks to Linux just to paper over some of the Xen's own issues. M. -- Without deviation from the norm, progress is not possible.