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 4F1E2C3DA59 for ; Tue, 16 Jul 2024 10:16:25 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1sTfDQ-0004nv-Ou; Tue, 16 Jul 2024 06:15:25 -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 1sTfDM-0004nA-SO for qemu-devel@nongnu.org; Tue, 16 Jul 2024 06:15:20 -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 1sTfDJ-00060U-VQ for qemu-devel@nongnu.org; Tue, 16 Jul 2024 06:15:20 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1721124914; 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=0njENZQPQiFEtWR5OrUYIMAkmtiD62XOlemDsVtllj8=; b=gVwms3WKlnUd7+QTss5Qu77gI/pzMgq1Rq79+DH1XeN5VUFJzWsM30pEgx+ZNH/KAPM2fz MZrD4cYmDxZy7zWZOW6yLioqGnTGsciCT5m3aIHpqC9bArs6K7ffIo1RASiAsTgHJiHZNi ZLBQ4KqkmB+o8RFtIMLyXKFiTo3MFa4= Received: from mail-wm1-f72.google.com (mail-wm1-f72.google.com [209.85.128.72]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-312-WWTm7rA6OQaQWdgTYWLMYw-1; Tue, 16 Jul 2024 06:15:12 -0400 X-MC-Unique: WWTm7rA6OQaQWdgTYWLMYw-1 Received: by mail-wm1-f72.google.com with SMTP id 5b1f17b1804b1-42668699453so50099835e9.3 for ; Tue, 16 Jul 2024 03:15:12 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1721124911; x=1721729711; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=0njENZQPQiFEtWR5OrUYIMAkmtiD62XOlemDsVtllj8=; b=kyFtv5pTrNrN9v0SgxOfPaFqOEyMvGnDRhgJ22DuhYhN87Vx2heVrbQZCpExHlMsun 8VZTKZc4jH1ijji22XumDkI7c9nj6NrliQzeDEo+z0T42YvL5+DHU2neRBJ8YAZJ/XNi K2Uy5JbBmxUsxooubgJNI/WkbJcZ3+zMjXWgcXqNZeP0za8ZZt3vnNw34Y8N884WFYuK 39EPYepuR9HlcoRCm2/OdbT7N5qz1ktyXnyVlnXCXy2EjJvXFup+BV8gmiOQpEzqryOn +uYYLLw/HKjrB6BwhZRGGdM0V5r47ln5jub2uAMxalZB/WOzEY37GrkQEB8EjwH3fKmt YTNQ== X-Gm-Message-State: AOJu0YzcAVSGZ4WUAjRegroX0rSIjCBO9gfDpfsubstZFbmw92GfrI9n 46puDIr42eXuT1jtGraGht1tJwRzaFW76FcTIuv0r6NRfzicUFLcyhUrHkPz43peVmO9NiWEHXZ FoWGJh9QMQHuXcT/Gm9XlXbkDPLvB/mntY3O4GZaC2Amc1a488Mii11jWmhpc+SCiIzJ2ITNVXB vR6CdmagF1wrMkDtvw4wNikC6Ksco= X-Received: by 2002:a05:600c:1e14:b0:426:58cb:8ca4 with SMTP id 5b1f17b1804b1-427ba720da7mr12914115e9.37.1721124911552; Tue, 16 Jul 2024 03:15:11 -0700 (PDT) X-Google-Smtp-Source: AGHT+IFwqdb3z8jrtZBFAqcPQulCKJJwx/cIyqqBQLzLohF+lsEdAjCytLECZTJwHgTNgAccRXGTN2ZLfHpY4ytrPTU= X-Received: by 2002:a05:600c:1e14:b0:426:58cb:8ca4 with SMTP id 5b1f17b1804b1-427ba720da7mr12913925e9.37.1721124911242; Tue, 16 Jul 2024 03:15:11 -0700 (PDT) MIME-Version: 1.0 References: <20240711131424.181615-1-ppandit@redhat.com> In-Reply-To: From: Prasad Pandit Date: Tue, 16 Jul 2024 15:44:54 +0530 Message-ID: Subject: Re: [PATCH 0/2] Postcopy migration and vhost-user errors To: Peter Xu Cc: qemu-devel@nongnu.org, Fabiano Rosas , Jason Wang , "Michael S . Tsirkin" , mcoqueli@redhat.com, Prasad Pandit Content-Type: text/plain; charset="UTF-8" Received-SPF: pass client-ip=170.10.133.124; envelope-from=ppandit@redhat.com; helo=us-smtp-delivery-124.mimecast.com 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: 2.1.29 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 Hello Peter, On Mon, 15 Jul 2024 at 19:10, Peter Xu wrote: > IMHO it's better we debug and fix all the issues before merging this one, > otherwise we may overlook something. * Well we don't know where the issue is, not sure where the fix may go in, ex. if the issue turns out to be how virsh(1) invokes migrate-postcopy, fix may go in virsh(1). Patches in this series anyway don't help to fix the migration convergence issue, so they could be reviewed independently I guess. > You could pass over the patch to whoever going to debug this, so it will be included in the whole set to be > posted when the bug is completely fixed. * Yes, this patch series is linked there. > The protocol should have no restriction on the thread model of a front-end. > It only describes the wire protocol. > > IIUC the protocol was designed to be serialized by nature (where there's no > request ID, so we can't match reply to any of the previous response), then > the front-end can manage the threads well to serialize all the requests, > like using this rwlock. * I see, okay. The simple protocol definition seems to indicate that it is meant for one front-end/back-end pair. If we are dividing the front-end across multiple threads, maybe we need a document to describe those threads and how they work, at least for the QEMU (front-end) side. Because the back-end could be a non-QEMU process, we can not do much there. (just thinking) Thank you. --- - Prasad