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=-0.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 9AEB0C433DF for ; Wed, 20 May 2020 16:46:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6BFC82065F for ; Wed, 20 May 2020 16:46:47 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="VovyrsBq" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726827AbgETQqq (ORCPT ); Wed, 20 May 2020 12:46:46 -0400 Received: from us-smtp-1.mimecast.com ([205.139.110.61]:23633 "EHLO us-smtp-delivery-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726821AbgETQqq (ORCPT ); Wed, 20 May 2020 12:46:46 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1589993204; 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: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=7vjx9ftJhMQ0P4vMekqxWsrl2y5tpT+NNgg8eoV8o3U=; b=VovyrsBq8JfQoXGS+LnrVkcIU6uCx6ryH+7UiKW/4kp7c9YdclloNBBk7OatJqVumENeEd f3hdP7iQnovl0asNkIIrPXX2RaCgYlZgwxly7NcRv8cf/lH8OvT/5vR/OVi0GxJniWOkzu 5ykSjTNHDkJUMeTQXWdey/Ey3ZUw+74= 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-172-SrR44d4uOamW-7TG2ZJlow-1; Wed, 20 May 2020 12:46:38 -0400 X-MC-Unique: SrR44d4uOamW-7TG2ZJlow-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id D34D481CBE3; Wed, 20 May 2020 16:46:35 +0000 (UTC) Received: from w520.home (ovpn-112-50.phx2.redhat.com [10.3.112.50]) by smtp.corp.redhat.com (Postfix) with ESMTP id D99BB79C2B; Wed, 20 May 2020 16:46:12 +0000 (UTC) Date: Wed, 20 May 2020 10:46:12 -0600 From: Alex Williamson To: Kirti Wankhede Cc: Yan Zhao , , , , , , , , , , , , , , , , , , , , Subject: Re: [PATCH Kernel v22 0/8] Add UAPIs to support migration for VFIO devices Message-ID: <20200520104612.03a32977@w520.home> In-Reply-To: <97977ede-3c5b-c5a5-7858-7eecd7dd531c@nvidia.com> References: <1589781397-28368-1-git-send-email-kwankhede@nvidia.com> <20200519105804.02f3cae8@x1.home> <20200520025500.GA10369@joy-OptiPlex-7040> <97977ede-3c5b-c5a5-7858-7eecd7dd531c@nvidia.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Wed, 20 May 2020 19:10:07 +0530 Kirti Wankhede wrote: > On 5/20/2020 8:25 AM, Yan Zhao wrote: > > On Tue, May 19, 2020 at 10:58:04AM -0600, Alex Williamson wrote: > >> Hi folks, > >> > >> My impression is that we're getting pretty close to a workable > >> implementation here with v22 plus respins of patches 5, 6, and 8. We > >> also have a matching QEMU series and a proposal for a new i40e > >> consumer, as well as I assume GVT-g updates happening internally at > >> Intel. I expect all of the latter needs further review and discussion, > >> but we should be at the point where we can validate these proposed > >> kernel interfaces. Therefore I'd like to make a call for reviews so > >> that we can get this wrapped up for the v5.8 merge window. I know > >> Connie has some outstanding documentation comments and I'd like to make > >> sure everyone has an opportunity to check that their comments have been > >> addressed and we don't discover any new blocking issues. Please send > >> your Acked-by/Reviewed-by/Tested-by tags if you're satisfied with this > >> interface and implementation. Thanks! > >> > > hi Alex and Kirti, > > after porting to qemu v22 and kernel v22, it is found out that > > it can not even pass basic live migration test with error like > > > > "Failed to get dirty bitmap for iova: 0xca000 size: 0x3000 err: 22" > > > > Thanks for testing Yan. > I think last moment change in below cause this failure > > https://lore.kernel.org/kvm/1589871178-8282-1-git-send-email-kwankhede@nvidia.com/ > > > if (dma->iova > iova + size) > > break; > > Surprisingly with my basic testing with 2G sys mem QEMU didn't raise > abort on g_free, but I do hit this with large sys mem. > With above change, that function iterated through next vfio_dma as well. > Check should be as below: > > - if (dma->iova > iova + size) > + if (dma->iova > iova + size -1) Or just: if (dma->iova >= iova + size) Thanks, Alex > break; > > Another fix is in QEMU. > https://lists.gnu.org/archive/html/qemu-devel/2020-05/msg04751.html > > > > + range->bitmap.size = ROUND_UP(pages, 64) / 8; > > > > ROUND_UP(npages/8, sizeof(u64))? > > > > If npages < 8, npages/8 is 0 and ROUND_UP(0, 8) returns 0. > > Changing it as below > > - range->bitmap.size = ROUND_UP(pages / 8, sizeof(uint64_t)); > + range->bitmap.size = ROUND_UP(pages, sizeof(__u64) * > BITS_PER_BYTE) / > + BITS_PER_BYTE; > > I'm updating patches with these fixes and Cornelia's suggestion soon. > > Due to short of time I may not be able to address all the concerns > raised on previous versions of QEMU, I'm trying make QEMU side code > available for testing for others with latest kernel changes. Don't > worry, I will revisit comments on QEMU patches. Right now first priority > is to test kernel UAPI and prepare kernel patches for 5.8 > > Thanks, > Kirti >