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=-2.4 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,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 6DF3FC2D0EA for ; Wed, 8 Apr 2020 09:32:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 36233206F5 for ; Wed, 8 Apr 2020 09:32:42 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=alien8.de header.i=@alien8.de header.b="i2+/LJpz" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727878AbgDHJcl (ORCPT ); Wed, 8 Apr 2020 05:32:41 -0400 Received: from mail.skyhub.de ([5.9.137.197]:35764 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726605AbgDHJcl (ORCPT ); Wed, 8 Apr 2020 05:32:41 -0400 Received: from zn.tnic (p200300EC2F0A9300FDE94558DB0629D0.dip0.t-ipconnect.de [IPv6:2003:ec:2f0a:9300:fde9:4558:db06:29d0]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.skyhub.de (SuperMail on ZX Spectrum 128k) with ESMTPSA id BCABF1EC0C89; Wed, 8 Apr 2020 11:32:38 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=dkim; t=1586338358; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=iPiVn5HowtJr85j+TBk0a/GUa/dBFzq/G2s+PBaU0UM=; b=i2+/LJpzUTxmAF6wtYN+zAH1EbcY0+wvaJ8uqCEqmQUqo7MiaWnH1wPSPmdVFgmWHgBsq+ 6zfY44nvZjY2KVzGmNAOLoYSH53Ib6Wd05eJvn6ohvs4XFNYDk4Pn9hzxRxOYl+LsYKlIh L9x3m87CrvfeT5rmxFSr1Uv2a0HT0HU= Date: Wed, 8 Apr 2020 11:32:35 +0200 From: Borislav Petkov To: Andy Lutomirski Cc: Thomas Gleixner , Vivek Goyal , Peter Zijlstra , Andy Lutomirski , Paolo Bonzini , LKML , X86 ML , kvm list , stable Subject: Re: [PATCH v2] x86/kvm: Disable KVM_ASYNC_PF_SEND_ALWAYS Message-ID: <20200408093235.GB24663@zn.tnic> References: <877dyqkj3h.fsf@nanos.tec.linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Apr 07, 2020 at 09:48:02PM -0700, Andy Lutomirski wrote: > I’m fine with the flow being different. do_machine_check() could > have entirely different logic to decide the error in PV. Nope, do_machine_check() is already as ugly as it gets. I don't want any more crap in it. > But I think we should reuse the overall flow: kernel gets #MC with > RIP pointing to the offending instruction. If there’s an extable > entry that can handle memory failure, handle it. If it’s a user > access, handle it. If it’s an unrecoverable error because it was a > non-extable kernel access, oops or panic. > > The actual PV part could be extremely simple: the host just needs to > tell the guest “this #MC is due to memory failure at this guest > physical address”. No banks, no DIMM slot, no rendezvous crap > (LMCE), no other nonsense. It would be nifty if the host also told the > guest what the guest virtual address was if the host knows it. It better be a whole different path and a whole different vector. If you wanna keep it simple and apart from all of the other nonsense, then you can just as well use a completely different vector. Thx. -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette