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=-13.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 39BCDC433B4 for ; Fri, 9 Apr 2021 15:59:05 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id DC219610E5 for ; Fri, 9 Apr 2021 15:59:04 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org DC219610E5 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:37694 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lUtXD-00052u-O6 for qemu-devel@archiver.kernel.org; Fri, 09 Apr 2021 11:59:03 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:44788) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lUtVg-0004CP-KB for qemu-devel@nongnu.org; Fri, 09 Apr 2021 11:57:28 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:44537) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lUtVd-0003QZ-Vn for qemu-devel@nongnu.org; Fri, 09 Apr 2021 11:57:27 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1617983844; 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=nMiAWaUKVxKc6ZgyjnfHtXEmImY3x3rTp4rkzf6DRYs=; b=X3Puw5ZtWMor+iP7yO+zmqEyrY3+3zEfKyAVm50CwtfK7BYi3K5xhicAMaNpvYnYqs4IG7 LsNV+THSd1aWmyyxnEEA4w55guXCER9zsw6Ti2ihIoRjdQxCxpTW7qpJA5EVYZ8UT68Qkp BqpP5jmOchcJFOPTcvMFflaGRtbsSD4= 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-286-5BeDcIAhNVSeb8sMUORx8Q-1; Fri, 09 Apr 2021 11:57:20 -0400 X-MC-Unique: 5BeDcIAhNVSeb8sMUORx8Q-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 CD6BD1B18BC0; Fri, 9 Apr 2021 15:57:18 +0000 (UTC) Received: from horse.redhat.com (ovpn-116-67.rdu2.redhat.com [10.10.116.67]) by smtp.corp.redhat.com (Postfix) with ESMTP id AA7761B472; Fri, 9 Apr 2021 15:56:57 +0000 (UTC) Received: by horse.redhat.com (Postfix, from userid 10451) id 45B0B22054F; Fri, 9 Apr 2021 11:56:57 -0400 (EDT) Date: Fri, 9 Apr 2021 11:56:57 -0400 From: Vivek Goyal To: Anton Kuchin Subject: Re: [Virtio-fs] [PATCH] vhost-user-fs: fix features handling Message-ID: <20210409155657.GE1111800@redhat.com> References: <20210408195534.647895-1-antonkuchin@yandex-team.ru> MIME-Version: 1.0 In-Reply-To: <20210408195534.647895-1-antonkuchin@yandex-team.ru> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=vgoyal@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Received-SPF: pass client-ip=170.10.133.124; envelope-from=vgoyal@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -27 X-Spam_score: -2.8 X-Spam_bar: -- X-Spam_report: (-2.8 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: virtio-fs@redhat.com, qemu-devel@nongnu.org, Stefan Hajnoczi , "Michael S. Tsirkin" Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Thu, Apr 08, 2021 at 10:55:34PM +0300, Anton Kuchin wrote: > Make virtio-fs take into account server capabilities. > > Just returning requested features assumes they all of then are implemented > by server and results in setting unsupported configuration if some of them > are absent. > > Signed-off-by: Anton Kuchin [CC stefan and qemu-devel.] Can you give more details of what problem exactly you are facing. Or this fix is about avoiding a future problem where device can refuse to support a feature qemu is requesting for. IIUC, this patch is preparing a list of features vhost-user-fs device can support. Then it calls vhost_get_features() which makes sure that all these features are support by real vhost-user device (hdev->features). If not, then corresponding feature is reset and remaining features are returned to caller. This feature negotion bit is called in so many places that I am kind of lost that who should be doing what. Will leave it to Stefan who understands it much better. > --- > hw/virtio/vhost-user-fs.c | 17 +++++++++++++---- > 1 file changed, 13 insertions(+), 4 deletions(-) > > diff --git a/hw/virtio/vhost-user-fs.c b/hw/virtio/vhost-user-fs.c > index ac4fc34b36..6cf983ba0e 100644 > --- a/hw/virtio/vhost-user-fs.c > +++ b/hw/virtio/vhost-user-fs.c > @@ -24,6 +24,14 @@ > #include "monitor/monitor.h" > #include "sysemu/sysemu.h" > > +static const int user_feature_bits[] = { > + VIRTIO_F_VERSION_1, > + VIRTIO_RING_F_INDIRECT_DESC, > + VIRTIO_RING_F_EVENT_IDX, > + VIRTIO_F_NOTIFY_ON_EMPTY, > + VHOST_INVALID_FEATURE_BIT > +}; > + > static void vuf_get_config(VirtIODevice *vdev, uint8_t *config) > { > VHostUserFS *fs = VHOST_USER_FS(vdev); > @@ -129,11 +137,12 @@ static void vuf_set_status(VirtIODevice *vdev, uint8_t status) > } > > static uint64_t vuf_get_features(VirtIODevice *vdev, > - uint64_t requested_features, > - Error **errp) > + uint64_t features, Will it make sense to keep the name requested_features. This kind of makes it clear that caller is requesting these features. I feel there should be few lines of comments also to make it clear what this function is actually doing. Vivek > + Error **errp) > { > - /* No feature bits used yet */ > - return requested_features; > + VHostUserFS *fs = VHOST_USER_FS(vdev); > + > + return vhost_get_features(&fs->vhost_dev, user_feature_bits, features); > } > > static void vuf_handle_output(VirtIODevice *vdev, VirtQueue *vq) > -- > 2.25.1 > > > _______________________________________________ > Virtio-fs mailing list > Virtio-fs@redhat.com > https://listman.redhat.com/mailman/listinfo/virtio-fs