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=-1.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 60B66C11D04 for ; Thu, 20 Feb 2020 13:15:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 38B1D24650 for ; Thu, 20 Feb 2020 13:15:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1582204513; bh=GBYBc5/faaisNgLYson35enBOGC+Q1UvdM6+pUdc8O8=; h=Date:From:To:Cc:Subject:In-Reply-To:References:List-ID:From; b=EZR8AAmakrerkxveRJ1daUkdiCUqV85HG7YfgymC+lrNn2l80FJh6kciE0kgCixSn 3KDBzIKKDrTdjwjPR2hx3bico6dCLi160Az6i4Anb8kaP7H4BqO81UBt1+crIvTmbI /Sj91XxThOgIuUaLc89XXXDTBNayH9Uh6KQMMxGE= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727979AbgBTNPM (ORCPT ); Thu, 20 Feb 2020 08:15:12 -0500 Received: from mail.kernel.org ([198.145.29.99]:52710 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727931AbgBTNPM (ORCPT ); Thu, 20 Feb 2020 08:15:12 -0500 Received: from disco-boy.misterjones.org (disco-boy.misterjones.org [51.254.78.96]) (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 47520206ED; Thu, 20 Feb 2020 13:15:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1582204511; bh=GBYBc5/faaisNgLYson35enBOGC+Q1UvdM6+pUdc8O8=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=t0so2L4yh+HxAPZONaJIbQajjtbOQuEvn6N7oU46SIcmoB3Yude7mAJ0xs+GZObbg Z6zqzFJmZKGh9vGXlOoaZC/zGFwTNSlhgY34KSV3LOMDmq23fLVJjOFKifKkl4M+vl 4HHbUC8SB6aGlO/FF8gWeNll27iSp5LXqhUFZ6tM= Received: from disco-boy.misterjones.org ([51.254.78.96] helo=www.loen.fr) by disco-boy.misterjones.org with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.92) (envelope-from ) id 1j4lfZ-006jVo-Ix; Thu, 20 Feb 2020 13:15:09 +0000 MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Date: Thu, 20 Feb 2020 13:15:09 +0000 From: Marc Zyngier To: Marek Szyprowski Cc: linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org, Vladimir Murzin , Russell King , Arnd Bergmann , Suzuki K Poulose , Quentin Perret , Christoffer Dall , James Morse , Paolo Bonzini , Will Deacon , Julien Thierry , Krzysztof Kozlowski , Bartlomiej Zolnierkiewicz Subject: Re: [RFC PATCH 0/5] Removing support for 32bit KVM/arm host In-Reply-To: <621a0a92-6432-6c3e-cb69-0b601764fa69@samsung.com> References: <20200210141324.21090-1-maz@kernel.org> <621a0a92-6432-6c3e-cb69-0b601764fa69@samsung.com> Message-ID: <43446bd5e884ae92f243799cbe748871@kernel.org> X-Sender: maz@kernel.org User-Agent: Roundcube Webmail/1.3.10 X-SA-Exim-Connect-IP: 51.254.78.96 X-SA-Exim-Rcpt-To: m.szyprowski@samsung.com, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org, vladimir.murzin@arm.com, linux@arm.linux.org.uk, arnd@arndb.de, suzuki.poulose@arm.com, qperret@google.com, Christoffer.Dall@arm.com, james.morse@arm.com, pbonzini@redhat.com, will@kernel.org, julien.thierry.kdev@gmail.com, krzk@kernel.org, b.zolnierkie@samsung.com X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Hi Marek, On 2020-02-20 12:44, Marek Szyprowski wrote: > Hi Marc, > > On 10.02.2020 15:13, 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) >> - It is more and more getting in the way of new arm64 developments > > That is a bit sad information. Mainline Exynos finally got everything > that was needed to run it on the quite popular Samsung Exynos5422-based > Odroid XU4/HC1/MC1 boards. According to the Odroid related forums it is > being used. We also use it internally at Samsung. Something like "too little, too late" springs to mind, but let's be constructive. Is anyone using it in a production environment, where they rely on the latest mainline kernel having KVM support? The current proposal is to still have KVM support in 5.6, as well as ongoing support for stable kernels. If that's not enough, can you please explain your precise use case? M. -- Jazz is not dead. It just smells funny...