From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([209.51.188.92]:45680) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gkR7F-00034f-9m for qemu-devel@nongnu.org; Fri, 18 Jan 2019 05:11:10 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gkR7E-0000BE-Kh for qemu-devel@nongnu.org; Fri, 18 Jan 2019 05:11:09 -0500 Received: from mx1.redhat.com ([209.132.183.28]:50711) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1gkR7E-0000A3-CP for qemu-devel@nongnu.org; Fri, 18 Jan 2019 05:11:08 -0500 References: <20190118100159.GA2483@work-vm> From: Paolo Bonzini Message-ID: <8f0f7339-5f47-46d0-20a9-343badad4d0f@redhat.com> Date: Fri, 18 Jan 2019 11:11:01 +0100 MIME-Version: 1.0 In-Reply-To: <20190118100159.GA2483@work-vm> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] Live migration from Qemu 2.12 hosts to Qemu 3.2 hosts, with VMX flag enabled in the guest? List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Dr. David Alan Gilbert" , Mark Mielke Cc: qemu-devel@nongnu.org, christian.ehrhardt@canonical.com On 18/01/19 11:02, Dr. David Alan Gilbert wrote: >> >> It fails if the flag is set, rather than if any nested virtualization has >> been used before. >> >> I'm concerned I will end up with a requirement for *all* guests to be >> restarted in order to migrate them to the new hosts, rather than just the >> ones that would have a problem. > I think you should be able to migrate from 2.12->3.1 like this, but > you'd hit the problem when you then try and migrate again between your > new QEMUs. > > I guess we could modify it to wire it to machine type, so that > older machine types didn't block. That would also be wrong. The old machine types _could_ be using KVM and they have no way to block the live migration. The solution is to restart the VM using "-cpu host,-vmx". Paolo