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=-4.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 9BD32C04AA7 for ; Mon, 13 May 2019 10:21:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6B4DD20989 for ; Mon, 13 May 2019 10:21:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729059AbfEMKVZ (ORCPT ); Mon, 13 May 2019 06:21:25 -0400 Received: from szxga07-in.huawei.com ([45.249.212.35]:37138 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728848AbfEMKUj (ORCPT ); Mon, 13 May 2019 06:20:39 -0400 Received: from DGGEMS406-HUB.china.huawei.com (unknown [172.30.72.59]) by Forcepoint Email with ESMTP id B2A51795AEB80AF6238C; Mon, 13 May 2019 18:20:35 +0800 (CST) Received: from [127.0.0.1] (10.142.68.147) by DGGEMS406-HUB.china.huawei.com (10.3.19.206) with Microsoft SMTP Server id 14.3.439.0; Mon, 13 May 2019 18:20:24 +0800 Subject: Re: [RFC PATCH V2] kvm: arm64: export memory error recovery capability to user space To: Peter Maydell CC: Christoffer Dall , Marc Zyngier , James Morse , =?UTF-8?B?UmFkaW0gS3LEjW3DocWZ?= , Jonathan Corbet , Catalin Marinas , Will Deacon , kvm-devel , "open list:DOCUMENTATION" , lkml - Kernel Mailing List , arm-mail-list , , "Zheng Xiang" References: <1557728917-49079-1-git-send-email-gengdongjiu@huawei.com> From: gengdongjiu Message-ID: Date: Mon, 13 May 2019 18:20:14 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.3.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.142.68.147] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2019/5/13 17:44, Peter Maydell wrote: > On Mon, 13 May 2019 at 07:32, Dongjiu Geng wrote: >> >> When user space do memory recovery, it will check whether KVM and >> guest support the error recovery, only when both of them support, >> user space will do the error recovery. This patch exports this >> capability of KVM to user space. >> >> Cc: Peter Maydell >> Signed-off-by: Dongjiu Geng >> --- >> v1->v2: >> 1. check whether host support memory failure instead of RAS capability >> https://patchwork.kernel.org/patch/10730827/ >> >> v1: >> 1. User space needs to check this capability of host is suggested by Peter[1], >> this patch as RFC tag because user space patches are still under review, >> so this kernel patch is firstly sent out for review. >> >> [1]: https://patchwork.codeaurora.org/patch/652261/ >> --- > > I thought the conclusion of the thread on the v1 patch was that > userspace doesn't need to specifically ask the host kernel if > it has support for this -- if it does not, then the host kernel > will just never deliver userspace any SIGBUS with MCEERR code, > which is fine. Or am I still confused? thanks Peter's quick reply. yes, I think so, if it does not support, then the host kernel will just never deliver userspace any SIGBUS with MCEERR code. so maybe we do not need this patch. > > thanks > -- PMM > . >