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 X-Spam-Level: X-Spam-Status: No, score=-2.5 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B0171C352A3 for ; Mon, 10 Feb 2020 15:46:19 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 857B920838 for ; Mon, 10 Feb 2020 15:46:19 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="EQZDV+/5"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="Nbgh66A2" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 857B920838 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=41ABRHsQwcNrzw+R25C+8M/AdJqoiP9pPlZhcomQn24=; b=EQZDV+/5qPCedE mPJnxy/r3+7uQ7rGBcT22CDvW5IxWWh9SeIyGOkl6blWjFD8RSIrpQW1ZiUUHl1b09bCMY5F4YCDt cV+7x6OJLTUAci48yYw4KpuPNc1mFk0Iso9KiMx8opOWblJexpfHErpnBPMG+v9zcG6nwwW6IlYuw GM6eD92vA6YPgxVc9pyRwg8SZ+nZTaVGheg7NttKZ6S10iFLSEsbWBnHt3nYNUPi7fxOwTLAWD7h9 L/44IQXWf8OFjvg+UvfUHsF7+guT9CKoPPh6ya3hma4S0rk/6qtNL7zdwU9RPy2BOgDlNaAZzcv5L pCf5cgea+lGp/Fys5xxg==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1j1BGN-0007P4-6f; Mon, 10 Feb 2020 15:46:19 +0000 Received: from mail.kernel.org ([198.145.29.99]) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1j1BGK-0007Nm-QW for linux-arm-kernel@lists.infradead.org; Mon, 10 Feb 2020 15:46:18 +0000 Received: from willie-the-truck (236.31.169.217.in-addr.arpa [217.169.31.236]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 53B6620733; Mon, 10 Feb 2020 15:46:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1581349574; bh=TTGiUvb9RHz3hdhmJfOzp0KIapqFPLU42O9zSWvHhOE=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Nbgh66A2RBEWvXx6MerEIUd9giZyvTUtyT0g89HKzIxi8UAO5FFSC3DotkWGBZgWh 8VmqH2A4GRYx8VmqwMzWPYlvCHE9g4TRJiKoqXV66JFgqs70vggQKyGjqiH94fc6A/ x27HEPnRKKPuNUTsEcUCTryiOPmjdOg06CwR+Wdo= Date: Mon, 10 Feb 2020 15:46:08 +0000 From: Will Deacon To: Marc Zyngier Subject: Re: [RFC PATCH 0/5] Removing support for 32bit KVM/arm host Message-ID: <20200210154608.GA21086@willie-the-truck> References: <20200210141324.21090-1-maz@kernel.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20200210141324.21090-1-maz@kernel.org> 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-20200210_074616_880257_AAB27FE7 X-CRM114-Status: GOOD ( 13.29 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Anders Berg , Vladimir Murzin , Russell King , Arnd Bergmann , kvm@vger.kernel.org, Suzuki K Poulose , Quentin Perret , Christoffer Dall , James Morse , linux-arm-kernel@lists.infradead.org, Paolo Bonzini , kvmarm@lists.cs.columbia.edu, Julien Thierry Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Mon, Feb 10, 2020 at 02:13:19PM +0000, Marc Zyngier wrote: > KVM/arm was merged just over 7 years ago, and has lived a very quiet > life so far. It mostly works if you're prepared to deal with its > limitations, it has been a good prototype for the arm64 version, > but it suffers a few problems: > > - It is incomplete (no debug support, no PMU) > - It hasn't followed any of the architectural evolutions > - It has zero users (I don't count myself here) I tend to use it to test that it still works, but that's it. > - It is more and more getting in the way of new arm64 developments To echo this last point, we're currently looking at the possibility of using KVM to isolate VMs from the host in Android. The scope of the changes we think we'll have to make would mean effectively duplicating the existing code for 32-bit or implementing a whole load of unused and untested functionality to keep the current structure. Neither of these options are particularly satisfactory from a maintainance point of view, so removing the 32-bit code if it doesn't have any significant use would be welcomed: Acked-by: Will Deacon Will _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel