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=-5.1 required=3.0 tests=BAYES_00,DATE_IN_PAST_96_XX, DKIM_INVALID,DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 E9AEDC48BDF for ; Tue, 15 Jun 2021 15:21:36 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 99921610EA for ; Tue, 15 Jun 2021 15:21:36 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 99921610EA Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:53460 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ltAsh-0007jT-OK for qemu-devel@archiver.kernel.org; Tue, 15 Jun 2021 11:21:35 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:54784) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ltArt-0006LE-0S for qemu-devel@nongnu.org; Tue, 15 Jun 2021 11:20:45 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:23512) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ltArr-0005Wa-3n for qemu-devel@nongnu.org; Tue, 15 Jun 2021 11:20:44 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1623770442; 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: in-reply-to:in-reply-to:references:references; bh=Env3el8FpSQxTHQa91umcHPfEZBrjkV0I88vvzxNt1M=; b=K5kR0tfGBJm/yfGUGptfYFhA9xUT9yFG1JMlvUvZuPohE9t6AAFJ4RptcAEo+k5rPGNnQ7 KC2dXeIOc8CuvRUhbbZlGygMRkbkbvT+aKJDUFAwaORK/kaS81zFMZxEGffmx9Ne78Bklu h07I2RhrA/VkXMlQFVuzd7COMP80zuM= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-477-PBvaKYtGNvq1Sg1Zz_s-lQ-1; Tue, 15 Jun 2021 11:20:40 -0400 X-MC-Unique: PBvaKYtGNvq1Sg1Zz_s-lQ-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 901CC10B7466; Tue, 15 Jun 2021 15:20:39 +0000 (UTC) Received: from localhost (unknown [10.22.8.244]) by smtp.corp.redhat.com (Postfix) with ESMTP id 5A5165C1C2; Tue, 15 Jun 2021 15:20:38 +0000 (UTC) Date: Tue, 8 Jun 2021 09:52:07 -0300 From: Eduardo Habkost To: Vitaly Kuznetsov Subject: Re: [PATCH v8 3/9] i386: hardcode supported eVMCS version to '1' Message-ID: <20210608125207.xxhvuh7ktxspo3bj@habkost.net> References: <20210608120817.1325125-1-vkuznets@redhat.com> <20210608120817.1325125-4-vkuznets@redhat.com> MIME-Version: 1.0 In-Reply-To: <20210608120817.1325125-4-vkuznets@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=ehabkost@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Received-SPF: pass client-ip=216.205.24.124; envelope-from=ehabkost@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: 4 X-Spam_score: 0.4 X-Spam_bar: / X-Spam_report: (0.4 / 5.0 requ) BAYES_00=-1.9, DATE_IN_PAST_96_XX=3.405, DKIMWL_WL_HIGH=-0.197, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=no autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: "Michael S. Tsirkin" , Marcelo Tosatti , qemu-devel@nongnu.org, Igor Mammedov , Paolo Bonzini Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Tue, Jun 08, 2021 at 02:08:11PM +0200, Vitaly Kuznetsov wrote: > Currently, the only eVMCS version, supported by KVM (and described in TLFS) > is '1'. When Enlightened VMCS feature is enabled, QEMU takes the supported > eVMCS version range (from KVM_CAP_HYPERV_ENLIGHTENED_VMCS enablement) and > puts it to guest visible CPUIDs. When (and if) eVMCS ver.2 appears a > problem on migration is expected: it doesn't seem to be possible to migrate > from a host supporting eVMCS ver.2 to a host, which only support eVMCS > ver.1. Should we rewrite this as "it wouldn't be possible to migrate", as this patch fixes the problem and makes it possible? > > Hardcode eVMCS ver.1 as the result of 'hv-evmcs' enablement for now. Newer > eVMCS versions will have to have their own enablement options (e.g. > 'hv-evmcs=2'). > > Signed-off-by: Vitaly Kuznetsov Reviewed-by: Eduardo Habkost -- Eduardo