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 54F42E7717D for ; Thu, 12 Dec 2024 00:15:33 +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=8Q8RLGRZwG3c++ek3HDNyZ1jXhiyW1baJM0ChZ43hrQ=; b=4BHc3y4e88dpTKANqH1LcG2P+R DVOhoibXF6MfKX08ZAKLRfLDJEzb/H5TwqWFcz8HqzGT3/+E0xFEzmkRGvJ5bNAvZKL7R+be7m8rP jp9Pe7JiYJ0FkrW1IH0oNNiBLHbwFcG/S3d4ruHPTg7e4Ui84z0TIMZAV9+angvPLOqd55U0Vn3rj o8DNmKen/Gyvfuhj4SxRPWbrYIR+RH9kgJlWIvB84WL/Cl90P1R6wyRMGr56Gu8iDrRJ1BsarPtsd ajBLqbxjGV8Sc5AYmGLtduO/SvJgDvuuNAuBKa9XHksqhTNU+H3uMiTOtYvRjwmIiG+vxKOogDUa9 QlGR0kVw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1tLWrT-0000000GaA5-3NHZ; Thu, 12 Dec 2024 00:15:23 +0000 Received: from dfw.source.kernel.org ([2604:1380:4641:c500::1]) by bombadil.infradead.org with esmtps (Exim 4.98 #2 (Red Hat Linux)) id 1tLVgA-0000000GQ9A-10V8 for linux-arm-kernel@lists.infradead.org; Wed, 11 Dec 2024 22:59:39 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by dfw.source.kernel.org (Postfix) with ESMTP id 379975C5632; Wed, 11 Dec 2024 22:58:55 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 544C4C4CED2; Wed, 11 Dec 2024 22:59:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1733957977; bh=ba8OhYJWZ7/RdSdR8zo6eTaxvZtkyE7pWbYivefWwDo=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=WaW+15dgE5AhR7mM92AiA6N5aJE7lkhwrwK16HZxjs4UoJDius5M1h9sMsfQmFYRJ k4G+vsfFOATgIp4A9IWmEDFXj2uAEANp3yfKGYKxdInMn8EgftnquPb91kaVHKroiW ro09RxLYMw8dcZu/Ii/Ny2j9diSMfFbubvjCkbampS7gmb5oXyIHzZ3HezADhQxLsJ kLtQmKUCKChmXo1gLDb5N9G6fk88uyjFB1OdDva8/FHvdXnzTcnimD5ILgDGNoI//6 Mvq/J5aBVmgX0czKCB9R0vqUxmSaexbQItgIfnNj3BUQUqlWpcYI61Sjqn3U+6acYH upCxWWuLsTdGg== Date: Wed, 11 Dec 2024 22:59:32 +0000 From: Will Deacon To: Alexandru Elisei Cc: julien.thierry.kdev@gmail.com, kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, maz@kernel.org, oliver.upton@linux.dev, apatel@ventanamicro.com, andre.przywara@arm.com, suzuki.poulose@arm.com, s.abdollahi22@imperial.ac.uk Subject: Re: [PATCH RESEND kvmtool 0/4] arm: Payload memory layout change Message-ID: <20241211225931.GC17836@willie-the-truck> References: <20241128151246.10858-1-alexandru.elisei@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20241128151246.10858-1-alexandru.elisei@arm.com> User-Agent: Mutt/1.10.1 (2018-07-13) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20241211_145938_322737_3162D756 X-CRM114-Status: GOOD ( 20.46 ) 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, Nov 28, 2024 at 03:12:42PM +0000, Alexandru Elisei wrote: > (resending because I accidently only sent the cover letter, sorry for that) > > The first 3 patches are fixes to kvm__arch_load_kernel_image(). I've CC'ed > the riscv maintainer because it looks to me like riscv is similarly > affected. > > Patch #4 ("arm64: Increase the payload memory region size to 512MB") might > be controversial. Follows a bug report I received from Abdollahi Sina in > private. Details in the commit message, but the gist of the patch is that > the memory region where kernel + initrd + DTB are copied to are changed > from 256MB to 512MB. As a result, the DTB and initrd are moved from below > ram_start + 256MB to ram_start + 512MB to accomodate a larger initrd. If > users rely on finding the DTB and initrd at the current addresses, then I'm > not sure the patch is justified - after all, if someone really wants to use > such a large initrd instead of a disk image with virtio, then replacing > SZ_256M with SZ_512M locally doesn't look like a big ask. > > On the other hand, if there are no users that rely on the current payload > layout, increasing the memory region size to 512MB to allow for more > unusual use cases, while still maintaining compatibility with older > kernels, doesn't seem unreasonable to me. > > Please comment, I don't feel strongly either way - I'll happy drop the last > patch if there are objections. Well, I won't reject an imperial.ac.uk patch on a hunch, so let's go for the whole lot and see if anybody complains! I'll fix the indentation issue spotted by Drew when applying (thanks!). Will