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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8FCCFC433F5 for ; Mon, 15 Nov 2021 14:43:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7201D61B6F for ; Mon, 15 Nov 2021 14:43:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232227AbhKOOqN (ORCPT ); Mon, 15 Nov 2021 09:46:13 -0500 Received: from smtp-out1.suse.de ([195.135.220.28]:58152 "EHLO smtp-out1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232156AbhKOOpo (ORCPT ); Mon, 15 Nov 2021 09:45:44 -0500 Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id E53D3212BE; Mon, 15 Nov 2021 14:42:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1636987367; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=CurHMBKJtGDElStoPcZcZiFRey4p43QkUhyCC85DQy8=; b=pxkXvCMQv5Aw/Dwj11Q1Yc61t5roI2OFQiwgMiOI56i7+CFiexIBAJMvBvB1/+c5/vhE/Y s58fOGRNhnOL9UQXVl4FmLw4iXuSY4HwqmtGcxuz5wr/kSfudc/1zFe6x5vr/TCVFhwS+O Pd+yrrNxBVpVig+F0x26RzQJeuoky8E= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1636987367; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=CurHMBKJtGDElStoPcZcZiFRey4p43QkUhyCC85DQy8=; b=CX/tmvhzVt1su/AdrYGXZ7EY04Z2tin5GBffGXKCePBskL8D1T22oMvRd4mX1yEX2nzdJs b6ak9mMTuAoFh5Aw== Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id 87AC713A66; Mon, 15 Nov 2021 14:42:46 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id vTH+HuZxkmGXMQAAMHmgww (envelope-from ); Mon, 15 Nov 2021 14:42:46 +0000 Date: Mon, 15 Nov 2021 15:42:44 +0100 From: Joerg Roedel To: "Dr. David Alan Gilbert" Cc: Sean Christopherson , Borislav Petkov , Dave Hansen , Peter Gonda , Brijesh Singh , x86@kernel.org, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, linux-coco@lists.linux.dev, linux-mm@kvack.org, linux-crypto@vger.kernel.org, Thomas Gleixner , Ingo Molnar , Tom Lendacky , "H. Peter Anvin" , Ard Biesheuvel , Paolo Bonzini , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Andy Lutomirski , Dave Hansen , Sergio Lopez , Peter Zijlstra , Srinivas Pandruvada , David Rientjes , Dov Murik , Tobin Feldman-Fitzthum , Michael Roth , Vlastimil Babka , "Kirill A . Shutemov" , Andi Kleen , tony.luck@intel.com, marcorr@google.com, sathyanarayanan.kuppuswamy@linux.intel.com Subject: Re: [PATCH Part2 v5 00/45] Add AMD Secure Nested Paging (SEV-SNP) Hypervisor Support Message-ID: References: <20210820155918.7518-1-brijesh.singh@amd.com> <061ccd49-3b9f-d603-bafd-61a067c3f6fa@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Nov 15, 2021 at 12:30:59PM +0000, Dr. David Alan Gilbert wrote: > Still; I wonder if it's best to kill the guest - maybe it's best for > the host to kill the guest and leave behind diagnostics of what > happened; for someone debugging the crash, it's going to be less useful > to know that page X was wrongly accessed (which is what the guest would > see), and more useful to know that it was the kernel's vhost-... driver > that accessed it. I is best to let the guest #VC on the page when this happens. If it happened because of a guest bug all necessary debugging data is in the guest and only the guest owner can obtain it. Then the guest owner can do a kdump on this unexpected #VC and collect the data to debug the issue. With just killing the guest from the host side this data would be lost. Regards, Joerg