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 B22A5C77B73 for ; Mon, 1 May 2023 20:27:04 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1pta6j-0007jf-F1; Mon, 01 May 2023 16:26:49 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pta6g-0007gA-1G for qemu-devel@nongnu.org; Mon, 01 May 2023 16:26:46 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pta6R-00009R-B2 for qemu-devel@nongnu.org; Mon, 01 May 2023 16:26:45 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1682972790; 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=NJe3VOdl4t6OgIBB7yOdzKeSbDGiF1bJcuTCCme9lJ8=; b=VrDGPr6rwkby2R+kkftOgq2WFh/wfrfaI+79gKehcE6B1H+KBPNp62x9tv7iPF1AV2XQsX AOJEPMVqAwt1b0YZUP/X4uTiDTn+OdlEJFfvHN7KSW8Nve2SnB0KmVWYtQW7lIjjeV3b9t ac3K9ObXnQD85QvJ//wkpUx5H3yzphQ= 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-324-w8LhreTSNKaeJU5d1FFZgw-1; Mon, 01 May 2023 16:26:28 -0400 X-MC-Unique: w8LhreTSNKaeJU5d1FFZgw-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.rdu2.redhat.com [10.11.54.7]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 55AEF29ABA0C; Mon, 1 May 2023 20:26:28 +0000 (UTC) Received: from localhost (unknown [10.39.192.107]) by smtp.corp.redhat.com (Postfix) with ESMTP id B095514152F6; Mon, 1 May 2023 20:26:27 +0000 (UTC) Date: Mon, 1 May 2023 16:26:26 -0400 From: Stefan Hajnoczi To: Yajun Wu Cc: qemu-devel@nongnu.org, "Michael S. Tsirkin" , Cindy Lu Subject: Re: [PATCH] vhost-user: send SET_STATUS 0 after GET_VRING_BASE Message-ID: <20230501202626.GB167911@fedora> References: <20230420130706.541219-1-stefanha@redhat.com> <7417a79f-bc46-8df3-c21a-2148c5ea513e@nvidia.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="Lhn94hiPDpj8WuFP" Content-Disposition: inline In-Reply-To: <7417a79f-bc46-8df3-c21a-2148c5ea513e@nvidia.com> X-Scanned-By: MIMEDefang 3.1 on 10.11.54.7 Received-SPF: pass client-ip=170.10.133.124; envelope-from=stefanha@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -22 X-Spam_score: -2.3 X-Spam_bar: -- X-Spam_report: (-2.3 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.171, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, 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-bounces+qemu-devel=archiver.kernel.org@nongnu.org --Lhn94hiPDpj8WuFP Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Fri, Apr 21, 2023 at 01:30:48PM +0800, Yajun Wu wrote: >=20 > On 4/20/2023 9:07 PM, Stefan Hajnoczi wrote: > >=20 > > Setting the VIRTIO Device Status Field to 0 resets the device. The > > device's state is lost, including the vring configuration. > >=20 > > vhost-user.c currently sends SET_STATUS 0 before GET_VRING_BASE. This > > risks confusion about the lifetime of the vhost-user state (e.g. vring > > last_avail_idx) across VIRTIO device reset. > >=20 > > Eugenio P=E9rez adjusted the order for vhost-vdpa= =2Ec > > in commit c3716f260bff ("vdpa: move vhost reset after get vring base") > > and in that commit description suggested doing the same for vhost-user > > in the future. > >=20 > > Go ahead and adjust vhost-user.c now. I ran various online code searches > > to identify vhost-user backends implementing SET_STATUS. It seems only > > DPDK implements SET_STATUS and Yajun Wu has > > confirmed that it is safe to make this change. > >=20 > > Cc: Michael S. Tsirkin > > Cc: Cindy Lu > > Signed-off-by: Stefan Hajnoczi > > --- > > hw/virtio/vhost-user.c | 13 ++++++++++++- > > 1 file changed, 12 insertions(+), 1 deletion(-) > >=20 > > diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c > > index e5285df4ba..2d40b1b3e7 100644 > > --- a/hw/virtio/vhost-user.c > > +++ b/hw/virtio/vhost-user.c > > @@ -2677,10 +2677,20 @@ static int vhost_user_dev_start(struct vhost_de= v *dev, bool started) > > VIRTIO_CONFIG_S_DRIVER | > > VIRTIO_CONFIG_S_DRIVER_OK); > > } else { > > - return vhost_user_set_status(dev, 0); > > + return 0; > > } > > } > >=20 > > +static void vhost_user_reset_status(struct vhost_dev *dev) > > +{ > > + /* Set device status only for last queue pair */ > > + if (dev->vq_index + dev->nvqs !=3D dev->vq_index_end) { > > + return; > > + } > > + > > + vhost_user_set_status(dev, 0); > > +} > > + > > const VhostOps user_ops =3D { > > .backend_type =3D VHOST_BACKEND_TYPE_USER, > > .vhost_backend_init =3D vhost_user_backend_init, > > @@ -2716,4 +2726,5 @@ const VhostOps user_ops =3D { > > .vhost_get_inflight_fd =3D vhost_user_get_inflight_fd, > > .vhost_set_inflight_fd =3D vhost_user_set_inflight_fd, > > .vhost_dev_start =3D vhost_user_dev_start, > > + .vhost_reset_status =3D vhost_user_reset_status, > > }; > > -- > > 2.39.2 > >=20 > Thank you for this fix. >=20 > Can you add protocol feature bit check, just like we do in > vhost_user_dev_start? >=20 > =A0=A0=A0 if (!virtio_has_feature(dev->protocol_features, > =A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0= =A0=A0=A0 VHOST_USER_PROTOCOL_F_STATUS)) { > =A0=A0=A0=A0=A0=A0=A0 return 0; > =A0=A0=A0 } Sure, will fix in v2. Stefan --Lhn94hiPDpj8WuFP Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAEBCAAdFiEEhpWov9P5fNqsNXdanKSrs4Grc8gFAmRQIHIACgkQnKSrs4Gr c8hkSQf9GyX4wcFVytafhuzVnH2eKxHYbfg95vMJ+OLvkr1cj7EBvYVdQw9T6oEw Y2DUF5FQMIWo8VSQITwWO4zerNPilCSJ69b7R343/mdglTlxsjc+FkPTcGWlsymG j1CdUQBnNkXEMoPMJTZg8t5xRRm1c/c8E8P3AAjWdISUrvfgo7KQbIllQr3oEi8G fWW9ES/XwtG0STQEWGxp/tUOzkys6+kPQIODmug7uDvgxxY09mwe665cgtdMiISc Fk04lZ3FDMswUrS49r4/r/UC5mW/U4vumkNb9ZnZo68zd6veTX58eIqiHWmqmOs1 RauTPh0+NOqTtTKQPxZWMILE2cLf8Q== =2z7k -----END PGP SIGNATURE----- --Lhn94hiPDpj8WuFP--