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=-11.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS 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 6076AC47095 for ; Wed, 9 Jun 2021 09:15:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4393A6120F for ; Wed, 9 Jun 2021 09:15:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233184AbhFIJQz (ORCPT ); Wed, 9 Jun 2021 05:16:55 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:52861 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231219AbhFIJQz (ORCPT ); Wed, 9 Jun 2021 05:16:55 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1623230100; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=sgi5kKOm6TK8M2qhVcZngliu9Y3bqvGLMIuAVTt+ubM=; b=AU3Wlgos3zGgY/TKDvyr1IbnJkNBDavbiZGSY12XQ0iFyCkMD4rQgA77R63apdr7IBMxea DZcall+EdnQB/QV0MsEOIFls0VhQ4fXigSkzybNoPxD5snPXucg4kh5MNEm3cPv4AxrxK8 0tdlsi9mF8TBTDjH+IkqVqwV4xCooAM= 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-68-vYCn498aOPKkd6o0B6dZIg-1; Wed, 09 Jun 2021 05:14:59 -0400 X-MC-Unique: vYCn498aOPKkd6o0B6dZIg-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 6495C100C661; Wed, 9 Jun 2021 09:14:58 +0000 (UTC) Received: from starship (unknown [10.40.194.6]) by smtp.corp.redhat.com (Postfix) with ESMTP id 6E2C760917; Wed, 9 Jun 2021 09:14:57 +0000 (UTC) Message-ID: Subject: Re: [Bug 53851] nVMX: Support live migration of whole L1 guest From: Maxim Levitsky To: bugzilla-daemon@bugzilla.kernel.org, kvm@vger.kernel.org Date: Wed, 09 Jun 2021 12:14:56 +0300 In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.36.5 (3.36.5-2.fc32) MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Wed, 2021-06-09 at 08:55 +0000, bugzilla-daemon@bugzilla.kernel.org wrote: > https://bugzilla.kernel.org/show_bug.cgi?id=53851 > > --- Comment #2 from christian.rohmann@frittentheke.de --- > Sorry for replying to this rather old bug - I was pointed to this via > https://www.linux-kvm.org/page/Nested_Guests#Limitations > > > If I may ask, is this really the last state of discussion and work on this > issue? > Looking at i.e. > > * https://github.com/qemu/qemu/commit/ebbfef2f34cfc749c045a4569dedb4f748ec024a > * > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=039aeb9deb9291f3b19c375a8bc6fa7f768996cc > > > there have been commits for the kernel as well as QEMU to support migration of > nested VMs. > AFAIK, running nested guests and migration while nested guest is running should work on both Intel and AMD, but there were lots of fixes in this area recently so a very new kernel should be used. Plus in some cases if the nested guest is 32 bit, the migration still can fail, on Intel at least, last time I checked. On AMD I just recently fixed such issue for 32 bit guest and it seems to work for me. I also know that if the nested guest is hyper-v enabled (which is a bit overkill as this brings us to a double nesting), then it crashes once in a whileafter lots of migration cycles. So there are still bugs, but overall it works. Best regards, Maxim Levitsky