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 97024C6787B for ; Fri, 25 Aug 2023 18:25:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:From:References:Cc:To: Subject:MIME-Version:Date:Message-ID:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=OvqlF6yblsGclWjS75i+HYX0QGmNfd6GYF/bZ2tqcYg=; b=NWJI6+wWaNj04g eU6kmhAi+EdZuYt/4iP26OwD+ZzocxaEZTPw8vha7cembgwvOAdz25BeBf35gnJe5QPBwchF4DyI0 xEbT6hgcM/cHU1ekIHzlSNF+3e+Xi785+H+2780VKwa0cHAB3AuUvvvu/3mlawgPRH1k1/LFLTH8y 8WCX9wwOyCo0HF1kWl+vX7jzWBkuNfS+bbpeclj7Ss/99/js2/ciVJYxIwh4NPF4OkRqsNVM+2+8y dfqiAlZywh6Q4TsPPS4tjDKlsNJ5KID6X2oeMll/g91+dd1fIaDTc6AyN7NyD/n1oeBuQBbSikZH9 KHOFNyTQCTyd2ge5CmuA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qZbUX-005rok-1P; Fri, 25 Aug 2023 18:25:05 +0000 Received: from linux.microsoft.com ([13.77.154.182]) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qZbUU-005rnE-1u for linux-arm-kernel@lists.infradead.org; Fri, 25 Aug 2023 18:25:03 +0000 Received: from [192.168.0.5] (71-212-112-68.tukw.qwest.net [71.212.112.68]) by linux.microsoft.com (Postfix) with ESMTPSA id D00DA2127C95; Fri, 25 Aug 2023 11:24:58 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com D00DA2127C95 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1692987899; bh=lTiAq6TIQlz3/KRzBrYOW9Zloaa6S2j8QsR1OWQ9nd0=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=O7+HQDi40dbcU5ZJ+REsZOWEZbODS6aqRVj4DMw9c6KTpW6MGAoCJiEkoiHCN9+lb qeO/sDXHDMnr3G3VhGWUbUBoBwRvv009PLONJU70BqfDsHZJ+EUTSjer4YwBIGwRdZ jJPkTnenGtlRUjYJeGFRyc2zXJLb3eQBXaQU9Y1A= Message-ID: Date: Fri, 25 Aug 2023 11:24:58 -0700 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2 13/15] uapi: hyperv: Add mshv driver headers hvhdk.h, hvhdk_mini.h, hvgdk.h, hvgdk_mini.h Content-Language: en-US To: Greg KH , Wei Liu Cc: linux-hyperv@vger.kernel.org, linux-kernel@vger.kernel.org, x86@kernel.org, linux-arm-kernel@lists.infradead.org, linux-arch@vger.kernel.org, patches@lists.linux.dev, mikelley@microsoft.com, kys@microsoft.com, haiyangz@microsoft.com, decui@microsoft.com, apais@linux.microsoft.com, Tianyu.Lan@microsoft.com, ssengar@linux.microsoft.com, mukeshrathor@microsoft.com, stanislav.kinsburskiy@gmail.com, jinankjain@linux.microsoft.com, vkuznets@redhat.com, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, hpa@zytor.com, will@kernel.org, catalin.marinas@arm.com References: <1692309711-5573-1-git-send-email-nunodasneves@linux.microsoft.com> <1692309711-5573-14-git-send-email-nunodasneves@linux.microsoft.com> <2023081923-crown-cake-79f7@gregkh> From: Nuno Das Neves In-Reply-To: <2023081923-crown-cake-79f7@gregkh> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230825_112502_664380_1EE40EC8 X-CRM114-Status: GOOD ( 14.64 ) 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: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 8/19/2023 3:26 AM, Greg KH wrote: > > My "strong" opinion is the one kernel development rule that we have, > "you can not break userspace". So, if you change these > values/structures/whatever in the future, and userspace tools break, > that's not ok and the changes have to be reverted. > > If you can control both sides of the API here (with open tools that you > can guarantee everyone will always update to), then yes, you can change > the api in the future. > This is true for us - we contribute and maintain support for this driver in Cloud Hypervisor[1], an open source VMM. We also do a check of the hypervisor version when the driver loads, and refuse to proceed if it is running on an incompatible hypervisor. Thanks, Nuno Das Neves [1] https://github.com/cloud-hypervisor/cloud-hypervisor _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel