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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 34D96D3B988 for ; Tue, 26 Nov 2024 11:59:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=w2S9QYgEQoKUpEwU39+L35Uj8JGecJ6e9hKFmaUPyHQ=; b=OYDl4A7/YJZEQDZ50/nxtJH8a3 JdPSa3bYm7DSaK71/bK/rIVolrsR7cZIvA4le9v2XqF0j6PZT2cP2uyxfx4ypG+2spr8VAJI+f7b6 KC+XHGukUWYpf0ZAvuAAfgK3zBqEohJk8xE+IfiGLkLZo0PhvMvC7DSNVKZ+4C1LueI8S//9G/x98 TVtl0yhPitMrv7hvCy5G1E/kuHx0NtVwqIdoVzL9q3Q47tWVS6x9dAGLCMgMG9B6ysGAMoLqqzma7 Q07j0bzbAezCgqRLkOlVZP4fD77ehob0hd04s09zOYhac+h6deR/HqbRpPHZSgsDvuHJMLhJFvxt7 XvLCB1MA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1tFuEC-0000000AUwO-3fZT; Tue, 26 Nov 2024 11:59:36 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1tFuDE-0000000AUq2-2qVx for linux-arm-kernel@lists.infradead.org; Tue, 26 Nov 2024 11:58:37 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 8A07F153B; Tue, 26 Nov 2024 03:59:03 -0800 (PST) Received: from J2N7QTR9R3 (usa-sjc-imap-foss1.foss.arm.com [10.121.207.14]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id D46CA3F58B; Tue, 26 Nov 2024 03:58:32 -0800 (PST) Date: Tue, 26 Nov 2024 11:58:30 +0000 From: Mark Rutland To: Luca Fancellu Cc: andre.przywara@arm.com, linux-arm-kernel@lists.infradead.org Subject: Re: [boot-wrapper v4 4/4] aarch64: Start Xen on Armv8-R at EL2 Message-ID: References: <20241017095520.939464-1-luca.fancellu@arm.com> <20241017095520.939464-5-luca.fancellu@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20241017095520.939464-5-luca.fancellu@arm.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20241126_035836_757446_40C1EBC5 X-CRM114-Status: GOOD ( 19.59 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Thu, Oct 17, 2024 at 10:55:20AM +0100, Luca Fancellu wrote: > When bootwrapper is compiled with Xen support and it is started > at EL2 on Armv8-R AArch64, keep the current EL and jump to the > Xen image using the SPSR_KERNEL as spsr_el2 value. What's the plan for booting Xen? i.e. is that using spin-table or PSCI? I'm hesitant to expose PSCI booting to EL2 on ARMv8-R, because PSCI doesn't really support ARMv8-R (the spec says nothing about it, and all we're doing is providing the illusion of ARMv8-A to Linux), and Xen would have to override the vectors anyway, so it doesn't really make sense. Given the latter part I'm assuming you only care about spin-table for Xen, which is less concerning. I think we should make that more explicit in the config options and forbid the combination of ARMv8-R + PSCI + Xen. Mark. > > Signed-off-by: Luca Fancellu > --- > v4 changes: > - no changes > --- > Makefile.am | 1 + > arch/aarch64/boot.S | 2 +- > 2 files changed, 2 insertions(+), 1 deletion(-) > > diff --git a/Makefile.am b/Makefile.am > index aecda694fd6c..a8d5c1b96822 100644 > --- a/Makefile.am > +++ b/Makefile.am > @@ -127,6 +127,7 @@ XEN_CHOSEN := xen,xen-bootargs = \"$(XEN_CMDLINE)\"; \ > compatible = \"xen,linux-zimage\", \"xen,multiboot-module\"; \ > reg = <0x0 $(DOM0_OFFSET) 0x0 $(KERNEL_SIZE)>; \ > }; > +DEFINES += -DXEN > endif > > if INITRD > diff --git a/arch/aarch64/boot.S b/arch/aarch64/boot.S > index 565397823cb4..3fcc63bf2437 100644 > --- a/arch/aarch64/boot.S > +++ b/arch/aarch64/boot.S > @@ -100,7 +100,7 @@ ASM_FUNC(jump_kernel) > mov x1, x21 > mov x2, x22 > mov x3, x23 > -#if defined(BOOTWRAPPER_64R) > +#if defined(BOOTWRAPPER_64R) && !defined(XEN) > // On Armv8-R Linux needs to be booted at EL1 > mov x4, #SPSR_KERNEL_EL1 > #else > -- > 2.34.1 >