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=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,UNPARSEABLE_RELAY 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 ADA03C07E96 for ; Thu, 8 Jul 2021 16:14:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9760A6139A for ; Thu, 8 Jul 2021 16:14:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229568AbhGHQQn (ORCPT ); Thu, 8 Jul 2021 12:16:43 -0400 Received: from forward1-smtp.messagingengine.com ([66.111.4.223]:60289 "EHLO forward1-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229554AbhGHQQn (ORCPT ); Thu, 8 Jul 2021 12:16:43 -0400 Received: from compute4.internal (compute4.nyi.internal [10.202.2.44]) by mailforward.nyi.internal (Postfix) with ESMTP id BB3AB1940BBC; Thu, 8 Jul 2021 12:14:00 -0400 (EDT) Received: from mailfrontend2 ([10.202.2.163]) by compute4.internal (MEProxy); Thu, 08 Jul 2021 12:14:00 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:content-type:date:from:in-reply-to :message-id:mime-version:references:subject:to:x-me-proxy :x-me-proxy:x-me-sender:x-me-sender:x-sasl-enc; s=fm3; bh=Y9L7mn PoCTM9eva9Nk3xNyfoePPSqUmsc1qRlRIrQdw=; b=WOCOEfVpAWhAx9OzZN72Gr yovqrAcfKcov4l0h4AYdb9AA0KufNz7Kf2PgRAdW+FeiWN17Bhg4Rdzr+ON4rxmd daS92GV3K4+3UX8QrLOtwAUkJegbir7Hub6diKYCDYADaSUnZEUuUYqHWJkjKu2y wCRTlpVmKb4OxF9Vo3fhDkG9rnYmtlBBHkfeSPvFNuBtudg/DlW6nGlhjzd7WU4R jJX9UowEKhixIdmB0/UDpICZfjzNlGt+CiRfeZ278zXDQ0FI7A4VB6FsD76aNHiE 01yA2k1PE1jHP+Tw52V0INtX/DVua7440LXLio8ZqiLDh5lUtmarG/q0aVpk201A == X-ME-Sender: X-ME-Received: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgedvtddrtdeggdeliecutefuodetggdotefrodftvf curfhrohhfihhlvgemucfhrghsthforghilhdpqfgfvfdpuffrtefokffrpgfnqfghnecu uegrihhlohhuthemuceftddtnecusecvtfgvtghiphhivghnthhsucdlqddutddtmdenuc fjughrpefvufgjfhfhfffkgggtsehttdertddttddtnecuhfhrohhmpeffrghvihguucfg ughmohhnughsohhnuceoughmvgesughmvgdrohhrgheqnecuggftrfgrthhtvghrnhephf ekgeeutddvgeffffetheejvdejieetgfefgfffudegffffgeduheegteegleeknecuvehl uhhsthgvrhfuihiivgeptdenucfrrghrrghmpehmrghilhhfrhhomhepughmvgesughmvg drohhrgh X-ME-Proxy: Received: by mail.messagingengine.com (Postfix) with ESMTPA; Thu, 8 Jul 2021 12:13:59 -0400 (EDT) Received: from localhost (disaster-area.hh.sledj.net [local]) by disaster-area.hh.sledj.net (OpenSMTPD) with ESMTPA id 6ef51eab; Thu, 8 Jul 2021 16:13:57 +0000 (UTC) To: Richard Henderson , qemu-devel@nongnu.org Cc: Eduardo Habkost , kvm@vger.kernel.org, Michael Roth , Marcelo Tosatti , Cameron Esfahani , babu.moger@amd.com, Roman Bolshakov , Paolo Bonzini Subject: Re: [RFC PATCH 8/8] target/i386: Move X86XSaveArea into TCG In-Reply-To: References: <20210705104632.2902400-1-david.edmondson@oracle.com> <20210705104632.2902400-9-david.edmondson@oracle.com> <0d75c3ab-926b-d4cd-244a-8c8b603535f9@linaro.org> X-HGTTG: heart-of-gold From: David Edmondson Date: Thu, 08 Jul 2021 17:13:57 +0100 Message-ID: MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Thursday, 2021-07-08 at 08:22:02 -07, Richard Henderson wrote: > On 7/8/21 12:45 AM, David Edmondson wrote: >> Actually, that's nonsense. With KVM or HVF we have to use the offsets of >> the host CPU, as the hardware won't do anything else, irrespective of >> the general CPU model chosen. >> >> To have KVM -> TCG migration work it would be necessary to pass the >> offsets in the migration stream and have TCG observe them, as you >> originally said. >> >> TCG -> KVM migration would only be possible if TCG was configured to use >> the same offsets as would later required by KVM (meaning, the host CPU). > > And kvm -> kvm migration, with the same general cpu model chosen, but with different host > cpus with different offsets? > > It seems like we must migrate then and verify the offsets in that case, so that we can > fail the migration. Agreed. I will look into migrating the offsets. dme. -- The sound of a barking dog on a loop, a plane rises in the crystal blue.