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=-3.5 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED 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 02CB8C433DF for ; Mon, 19 Oct 2020 09:25:39 +0000 (UTC) Received: from mm01.cs.columbia.edu (mm01.cs.columbia.edu [128.59.11.253]) by mail.kernel.org (Postfix) with ESMTP id 31D3022200 for ; Mon, 19 Oct 2020 09:25:37 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="itjxMV7y" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 31D3022200 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvmarm-bounces@lists.cs.columbia.edu Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 5C5C34B560; Mon, 19 Oct 2020 05:25:37 -0400 (EDT) X-Virus-Scanned: at lists.cs.columbia.edu Authentication-Results: mm01.cs.columbia.edu (amavisd-new); dkim=softfail (fail, message has been altered) header.i=@redhat.com Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id XKNCpjwj5omc; Mon, 19 Oct 2020 05:25:36 -0400 (EDT) Received: from mm01.cs.columbia.edu (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 417834B56F; Mon, 19 Oct 2020 05:25:36 -0400 (EDT) Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 47C9B4B560 for ; Mon, 19 Oct 2020 05:25:35 -0400 (EDT) X-Virus-Scanned: at lists.cs.columbia.edu Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id hHUm-Bkdki56 for ; Mon, 19 Oct 2020 05:25:34 -0400 (EDT) Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [216.205.24.124]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 35CFE4B54B for ; Mon, 19 Oct 2020 05:25:34 -0400 (EDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1603099533; 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=S8Vq1Ap8SBigkU/8LGMXA2a9BrKy83dFwogd18gdHco=; b=itjxMV7yghLgIRICKcso5SEst/X51s5AlXHYACEswT438Dl8164UK4CpGsoS5Jpy/HTVk6 2Dik1H8Q06QNmy7WKWo+14c/ZFf1SFW0Fw2GhdC1RA4SzswmnFfn9ezrnd/xXPKUmhnGjo 2chJyyIKRgLspgqPMA64gvLMqe/RTCM= 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-239-2BZvLv5HObiGgA1Gim2UDA-1; Mon, 19 Oct 2020 05:25:32 -0400 X-MC-Unique: 2BZvLv5HObiGgA1Gim2UDA-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 7F888800462; Mon, 19 Oct 2020 09:25:30 +0000 (UTC) Received: from kamzik.brq.redhat.com (unknown [10.40.193.206]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 8F4C86EF46; Mon, 19 Oct 2020 09:25:28 +0000 (UTC) Date: Mon, 19 Oct 2020 11:25:25 +0200 From: Andrew Jones To: Peter Maydell Subject: Re: Kernel patch cases qemu live migration failed. Message-ID: <20201019092525.ekvgbcwwtm63pueu@kamzik.brq.redhat.com> References: <20201015040639.70C6D414009F@webmail.sinamail.sina.com.cn> <7fecfc67da4caab1d677a8b4cd5386b3@kernel.org> <20201015133505.ubxvbrt6xyvl4362@kamzik.brq.redhat.com> <16400df4bdf79b8b22e824eb1a20e2b4@kernel.org> <20201015144104.ytwzpxjlsgyun3ob@kamzik.brq.redhat.com> MIME-Version: 1.0 In-Reply-To: X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=drjones@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Disposition: inline Cc: Marc Zyngier , xu910121@sina.com, qemu-devel , kvmarm , "Dave.Martin" X-BeenThere: kvmarm@lists.cs.columbia.edu X-Mailman-Version: 2.1.14 Precedence: list List-Id: Where KVM/ARM decisions are made List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu On Thu, Oct 15, 2020 at 03:57:02PM +0100, Peter Maydell wrote: > On Thu, 15 Oct 2020 at 15:41, Andrew Jones wrote: > > The reporter states neither the source nor destination hardware supports > > SVE. My guess is that what's happening is the reserved ID register > > ID_UNALLOCATED(4,4) was showing up in the KVM_GET_REG_LIST count on > > the old kernel, but the new kernel filters it out. Maybe it is a > > bug to filter it out of the count, as it's a reserved ID register and > > I suppose the other reserved ID registers are still showing up? > > Yeah, RES0 ID registers should show up in the list, because otherwise > userspace has to annoyingly special case them when the architecture > eventually defines behaviour for them. > > Dave's comment in the kernel commit message > # ID_AA64ZFR0_EL1 is RO-RAZ for MRS/MSR when SVE is disabled for the > # guest, but for compatibility with non-SVE aware KVM implementations > # the register should not be enumerated at all for KVM_GET_REG_LIST > # in this case. > seems wrong to me -- for compatibility the register should remain > present and behave as RAZ/WI if SVE is disabled in the guest, > the same way it was before the kernel/KVM knew about SVE at all. Yup, I agree with you and I'll try writing a patch for this. Thanks, drew _______________________________________________ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm