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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]:40818 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kcTa3-0007k1-G5 for qemu-devel@archiver.kernel.org; Tue, 10 Nov 2020 08:21:03 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:48206) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kcTYe-0006lq-LL for qemu-devel@nongnu.org; Tue, 10 Nov 2020 08:19:36 -0500 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:59608) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1kcTYb-0006bP-8e for qemu-devel@nongnu.org; Tue, 10 Nov 2020 08:19:35 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1605014371; h=from:from:reply-to: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=/lbxmQ72vzxK6+JNK0tC8uxUl7s/vSTjNxtsvR/FT70=; b=fUsQmPkjzV1PBkgKN8obCIHFM91t8tPyrtlGmjKAfvn5/0ISQ2pSqBSRVAo/5C1ywYSqnY qk+Z/Q5i/lYFpa1r03nBkP0Nv9zpvekYt/LwwJp/dOOrAal/H2QinqnxPpvQpbWbIWRXVa wJ5wi82TowS03rrJYAWTTg2SPViBf/Q= 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-527-FRlvOXjHOo-ik2uxNC3SyQ-1; Tue, 10 Nov 2020 08:19:20 -0500 X-MC-Unique: FRlvOXjHOo-ik2uxNC3SyQ-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id DDD5A1087D67; Tue, 10 Nov 2020 13:19:18 +0000 (UTC) Received: from redhat.com (ovpn-115-68.ams2.redhat.com [10.36.115.68]) by smtp.corp.redhat.com (Postfix) with ESMTPS id B054A196FE; Tue, 10 Nov 2020 13:19:15 +0000 (UTC) Date: Tue, 10 Nov 2020 13:19:12 +0000 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Chuan Zheng Subject: Re: [PATCH] migration/multifd: fix hangup with TLS-Multifd due to blocking handshake Message-ID: <20201110131912.GF869656@redhat.com> References: <1604643893-8223-1-git-send-email-zhengchuan@huawei.com> MIME-Version: 1.0 In-Reply-To: <1604643893-8223-1-git-send-email-zhengchuan@huawei.com> User-Agent: Mutt/1.14.6 (2020-07-11) X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=berrange@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit Received-SPF: pass client-ip=216.205.24.124; envelope-from=berrange@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/11/10 02:00:53 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 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_NONE=-0.0001, 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: , Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Cc: yubihong@huawei.com, zhang.zhanghailiang@huawei.com, quintela@redhat.com, dgilbert@redhat.com, xiexiangyou@huawei.com, qemu-devel@nongnu.org, alex.chen@huawei.com, wanghao232@huawei.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Fri, Nov 06, 2020 at 02:24:53PM +0800, Chuan Zheng wrote: > The qemu main loop could hang up forever when we enable TLS+Multifd. > The Src multifd_send_0 invokes tls handshake, it sends hello to sever > and wait response. > However, the Dst main qemu loop has been waiting recvmsg() for multifd_recv_1. > Both of Src and Dst main qemu loop are blocking and waiting for reponse which > results in hanging up forever. > > Src: (multifd_send_0) Dst: (multifd_recv_1) > multifd_channel_connect migration_channel_process_incoming > multifd_tls_channel_connect migration_tls_channel_process_incoming > multifd_tls_channel_connect qio_channel_tls_handshake_task > qio_channel_tls_handshake gnutls_handshake > qio_channel_tls_handshake_task ... > qcrypto_tls_session_handshake ... > gnutls_handshake ... > ... ... > recvmsg (Blocking I/O waiting for response) recvmsg (Blocking I/O waiting for response) > > Fix this by offloadinig handshake work to a background thread. > > Reported-by: Yan Jin > Suggested-by: Daniel P. Berrangé > Signed-off-by: Chuan Zheng > --- > migration/multifd.c | 23 +++++++++++++++++------ > 1 file changed, 17 insertions(+), 6 deletions(-) Reviewed-by: Daniel P. Berrangé Regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|