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 77DAFC11D04 for ; Thu, 20 Feb 2020 11:01:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4AFA42465D for ; Thu, 20 Feb 2020 11:01:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1582196512; bh=75+xq+IHwaECZYb5L8KpYt15Oi/0cJIf79a3hrpZIN8=; h=Date:From:To:Cc:Subject:In-Reply-To:References:List-ID:From; b=qzs4NWOrDbcJ6bfzDcvYT8OBi0zqXrmHM1kQnGcj9OcvZ4kn4JS5hwmRFrBFqEyJg tuqFMisXvjSl3ZcgjbMokPIH3z4Sc6UBG8qrByCEm+ymuvEVNZTqt0abYDuZ5CorBN YoFpwME8wKOW1BX9tEUFkBljxj81VyZ3MgkvaK2E= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726927AbgBTLBv (ORCPT ); Thu, 20 Feb 2020 06:01:51 -0500 Received: from mail.kernel.org ([198.145.29.99]:46682 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726707AbgBTLBv (ORCPT ); Thu, 20 Feb 2020 06:01:51 -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 10B40208C4; Thu, 20 Feb 2020 11:01:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1582196510; bh=75+xq+IHwaECZYb5L8KpYt15Oi/0cJIf79a3hrpZIN8=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=w5d0iEJzl0jpxf97qkGXu/YehoA7Pybk3x+f8K45sCWbaTxVfd3oe12dwnZE8qiZi n8e9gykzGpCyv+O2oLVZWcmKHzjyTnCxuPzva+1TrudkCwvZbXXxlr/4FPQDlFrxAp 5c7olFr7AlBeRQsjVGrouBbIORKa5yzmQYFLZUIY= 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 1j4jaW-006i86-95; Thu, 20 Feb 2020 11:01:48 +0000 MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Date: Thu, 20 Feb 2020 11:01:48 +0000 From: Marc Zyngier To: Stefan Agner 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 Subject: Re: [RFC PATCH 0/5] Removing support for 32bit KVM/arm host In-Reply-To: <69845f739bbd91e73cd82e7c4683ab5a@agner.ch> References: <20200210141324.21090-1-maz@kernel.org> <69845f739bbd91e73cd82e7c4683ab5a@agner.ch> Message-ID: 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: stefan@agner.ch, 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 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 On 2020-02-19 13:53, Stefan Agner wrote: > On 2020-02-10 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 >> >> So here it is: unless someone screams and shows that they rely on >> KVM/arm to be maintained upsteam, I'll remove 32bit host support >> form the tree. One of the reasons that makes me confident nobody is >> using it is that I never receive *any* bug report. Yes, it is perfect. > > Not entirely true: > https://lore.kernel.org/m/e2f7196ca6c70c55463a45b490f6731a@agner.ch And I thank you for that. This bug was actually hitting both arm and arm64, and triggered by a bogus DT (that KVM should have handled in a nicer way). What I was trying to say is that nobody reports bugs that are specific to 32bit KVM/arm. > But, after that was fixed, it actually was perfect :-D > https://blog.printk.io/2016/09/kvm-with-kvmtool-on-armv7/ Hey, neat! not sure how useful, but neat nonetheless... ;-) > That said, I never used it in a real-world application, so from my side > removing it is fine. Thanks, M. -- Jazz is not dead. It just smells funny...