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 lists1p.gnu.org (lists1p.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 8F55DCD6E6E for ; Thu, 4 Jun 2026 19:48:34 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists1p.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1wVE2n-0006FB-4v; Thu, 04 Jun 2026 15:47:57 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists1p.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1wVE2i-0006EU-AV for qemu-devel@nongnu.org; Thu, 04 Jun 2026 15:47:53 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1wVE2g-0007tU-Lx for qemu-devel@nongnu.org; Thu, 04 Jun 2026 15:47:52 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1780602467; 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=jXSafxI5C+ejocUzXL62dyic+kxzIbswd9XrqBAojEA=; b=YnOLsDw3ZxNUksZRqeDBxZ1vDpjWPT/ijqycMHQYRE48918if2rcZ/bMQ9uXYcmyf1WTEM cTv2zlnFV3yaaUKnF8+E+3PXRSZDcgPEN8ctkeLxDYgv6OjHWbPjt0S58/Dp0E0hVgNxYM HNg2hPGu3IdiBX5T5pzJapwGK2/vg1o= Received: from mx-prod-mc-03.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-681-L3ALPqjCODiFwUVJnQXf0w-1; Thu, 04 Jun 2026 15:47:46 -0400 X-MC-Unique: L3ALPqjCODiFwUVJnQXf0w-1 X-Mimecast-MFC-AGG-ID: L3ALPqjCODiFwUVJnQXf0w_1780602465 Received: from mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.111]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 4A7CA1956046; Thu, 4 Jun 2026 19:47:45 +0000 (UTC) Received: from localhost (unknown [10.2.17.68]) by mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 56BB4180049F; Thu, 4 Jun 2026 19:47:44 +0000 (UTC) Date: Thu, 4 Jun 2026 15:47:43 -0400 From: Stefan Hajnoczi To: Stefano Garzarella Cc: qemu-devel@nongnu.org, "Michael S. Tsirkin" , hreitz@redhat.com, Pierrick Bouvier , gmaglione@redhat.com Subject: Re: [PATCH v2 2/3] libvhost-user: look for available vq buffers upon SET_VRING_KICK Message-ID: <20260604194743.GA149856@fedora> References: <20260519191548.335082-1-stefanha@redhat.com> <20260519191548.335082-3-stefanha@redhat.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="OjUM0IJowJDEy75W" Content-Disposition: inline In-Reply-To: X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.111 Received-SPF: pass client-ip=170.10.129.124; envelope-from=stefanha@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: 8 X-Spam_score: 0.8 X-Spam_bar: / X-Spam_report: (0.8 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.445, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, RCVD_IN_SBL_CSS=3.335, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 autolearn=no autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: qemu development 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 --OjUM0IJowJDEy75W Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, Jun 03, 2026 at 11:03:18AM +0200, Stefano Garzarella wrote: > On Tue, May 19, 2026 at 03:15:47PM -0400, Stefan Hajnoczi wrote: > > When a vring is started the back-end must look for available vq buffers > > and process them. This scenario can happen if the back-end is stopped > > with unprocessed available buffers and then started again. > >=20 > > The inflight I/O tracking code already did this, but it should also be > > done when inflight I/O tracking is not enabled. Move the code. > >=20 > > Signed-off-by: Stefan Hajnoczi > > --- > > subprojects/libvhost-user/libvhost-user.c | 10 +++++----- > > 1 file changed, 5 insertions(+), 5 deletions(-) > >=20 > > diff --git a/subprojects/libvhost-user/libvhost-user.c b/subprojects/li= bvhost-user/libvhost-user.c > > index 9c630c2170..2e286ea6d9 100644 > > --- a/subprojects/libvhost-user/libvhost-user.c > > +++ b/subprojects/libvhost-user/libvhost-user.c > > @@ -1390,11 +1390,6 @@ vu_check_queue_inflights(VuDev *dev, VuVirtq *vq) > > vq->counter =3D vq->resubmit_list[0].counter + 1; > > } > >=20 > > - /* in case of I/O hang after reconnecting */ > > - if (eventfd_write(vq->kick_fd, 1)) { > > - return -1; > > - } > > - > > return 0; > > } > >=20 > > @@ -1436,6 +1431,11 @@ vu_set_vring_kick_exec(VuDev *dev, VhostUserMsg = *vmsg) > > vu_panic(dev, "Failed to check inflights for vq: %d\n", index); > > } > >=20 > > + /* Inject a kick to look for available vq buffers */ > > + if (eventfd_write(dev->vq[index].kick_fd, 1)) { >=20 > Should we check if kick_fd is not -1 like we already do in other places in > this function? (mainly when `nofd` is true) > > > + return -1; >=20 > This function returns boolean, -1 is `true` and IIUC means that we ask fo= r a > reply which is not the case here. We should fix it. Thanks for catch these things. I'm going to redo this patch. Not sure what I was thinking :). Stefan --OjUM0IJowJDEy75W Content-Type: application/pgp-signature; name=signature.asc -----BEGIN PGP SIGNATURE----- iQEzBAEBCgAdFiEEhpWov9P5fNqsNXdanKSrs4Grc8gFAmoh1l8ACgkQnKSrs4Gr c8g+IQf+JBMZ/ZIgzXkUb8MPAeNPMzc3Y+yr7m/E9PaIVnDxDPzHATCgCXqiybKx yTZryijUx0xEplBZMXweOyDUO8KkBaLmp1ajhWWnylS6LAiwycq7nJqaGwDReiK/ rM5mEbb6gtAie2qBpvCKThMhDPeEoD4YrZWJljQpwH6GkDdFPlMHgag064nXgxyJ sJ3jDIEPBEGKGXzqgY4Knsa6zlBkVvMJJvCjjWlI6JFpoyOwKTcCWQU7lrPXEtrM AhjOLLNjtx0RGl0GQcreSEYNLNq4A6XEezekKR+gQp3NPsQQ4/eCGfORhUtgCbV9 4IabUPb8XmLD0PB+n1Hi5oYCGc+oYw== =gt1e -----END PGP SIGNATURE----- --OjUM0IJowJDEy75W--