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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 2A89DC433EF for ; Fri, 15 Jul 2022 07:28:26 +0000 (UTC) Received: from localhost ([::1]:33634 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1oCFkP-00012o-1O for qemu-devel@archiver.kernel.org; Fri, 15 Jul 2022 03:28:25 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:55714) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1oCFhP-0007KB-4V for qemu-devel@nongnu.org; Fri, 15 Jul 2022 03:25:19 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:43000) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1oCFhL-0000zh-FD for qemu-devel@nongnu.org; Fri, 15 Jul 2022 03:25:17 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1657869912; 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; bh=YMCa4CL7CI1xcJji7VdadzNsrL92RCbX96SQDLAxJG8=; b=Y4zmhoIIb9sYsQyQtmn3AbPTakf6RmIBearkGXw8C9uiZOlJ3CLFYDuHXrsm856msqjemc PHrOjyPyb3+Lz2NhnHdazE0FAElLMt8RheddCxprZCi7aKlzZkrk883cYgM5BvIbjdOE1i L6UxUri1oTiCL6Bik7lbKAb2C0MKRwg= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-586-ToqeP_YbPSCQQMWyxs9k0A-1; Fri, 15 Jul 2022 03:25:11 -0400 X-MC-Unique: ToqeP_YbPSCQQMWyxs9k0A-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id ADBF938041E4 for ; Fri, 15 Jul 2022 07:25:10 +0000 (UTC) Received: from eperezma.remote.csb (unknown [10.39.192.117]) by smtp.corp.redhat.com (Postfix) with ESMTP id BCE2A2166B26; Fri, 15 Jul 2022 07:25:09 +0000 (UTC) From: =?UTF-8?q?Eugenio=20P=C3=A9rez?= To: qemu-devel@nongnu.org Cc: Jason Wang , "Michael S. Tsirkin" Subject: [PATCH 0/2] vhost: Get vring base from vq, not svq Date: Fri, 15 Jul 2022 09:25:05 +0200 Message-Id: <20220715072507.2600431-1-eperezma@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable X-Scanned-By: MIMEDefang 2.78 on 10.11.54.6 Received-SPF: pass client-ip=170.10.133.124; envelope-from=eperezma@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -21 X-Spam_score: -2.2 X-Spam_bar: -- X-Spam_report: (-2.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.082, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" The SVQ vring used idx usually match with the guest visible one, as long=0D as all the guest buffers (GPA) maps to exactly one buffer within qemu's=0D VA. However, as we can see in virtqueue_map_desc, a single guest buffer=0D could map to many buffers in SVQ vring.=0D =0D The solution is to stop using the device's used idx and check for the=0D last avail idx. Since we cannot report in-flight descriptors with vdpa,=0D let's rewind all of them.=0D =0D Also, move this rewind to the destination, so we keep migrating the in-flig= ht=0D ones in case the destnation backend support them (vhost-kernel, emulated vi= rtio=0D in qemu, etc.)=0D =0D Eugenio P=C3=A9rez (2):=0D vhost: Get vring base from vq, not svq=0D vhost: Move SVQ queue rewind to the destination=0D =0D hw/virtio/vhost-vdpa.c | 24 ++++++++++++------------=0D 1 file changed, 12 insertions(+), 12 deletions(-)=0D =0D -- =0D 2.31.1=0D =0D