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 08502E7C4E2 for ; Wed, 4 Oct 2023 16:38:33 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qo4sk-00009X-0Q; Wed, 04 Oct 2023 12:37:54 -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 1qo4si-00008J-Mx for qemu-devel@nongnu.org; Wed, 04 Oct 2023 12:37:52 -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 1qo4sc-0002iY-K9 for qemu-devel@nongnu.org; Wed, 04 Oct 2023 12:37:52 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1696437465; 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=Fz1dga711r5xm336buv7guDNPzZ6c5/xwh/u37H8trI=; b=KEdniRtzJyXkP8FennfNvaCKqpZC4HzK5Gem4WPzmkPVMM/dj7qjw6i7/JwnIuxdCA0lNK OdCYjRClCEKpdShxSAkvDbtHXUYhGZTos0Ok4NljhKCh88g/7vTmZmbsGGtr3QUcvg2O3L SeweTBeOw2UwWuZd+P7WQ/leeOm1eEQ= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-549-ZaOdZC2BNhO-6RbfttvcTQ-1; Wed, 04 Oct 2023 12:37:43 -0400 X-MC-Unique: ZaOdZC2BNhO-6RbfttvcTQ-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.rdu2.redhat.com [10.11.54.7]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 8AFC21875053; Wed, 4 Oct 2023 16:37:43 +0000 (UTC) Received: from blackfin.pond.sub.org (unknown [10.39.192.25]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 6274A140E950; Wed, 4 Oct 2023 16:37:43 +0000 (UTC) Received: by blackfin.pond.sub.org (Postfix, from userid 1000) id 5D81D21E6904; Wed, 4 Oct 2023 18:37:42 +0200 (CEST) From: Markus Armbruster To: Juan Quintela Cc: qemu-devel@nongnu.org, peterx@redhat.com, leobras@redhat.com, farosas@suse.de, lizhijian@fujitsu.com, eblake@redhat.com Subject: Re: [PATCH v2 23/53] migration/rdma: Fix QEMUFileHooks method return values References: <20230928132019.2544702-1-armbru@redhat.com> <20230928132019.2544702-24-armbru@redhat.com> <87a5sywe6p.fsf@secure.mitica> Date: Wed, 04 Oct 2023 18:37:42 +0200 In-Reply-To: <87a5sywe6p.fsf@secure.mitica> (Juan Quintela's message of "Wed, 04 Oct 2023 18:22:06 +0200") Message-ID: <87jzs2bay1.fsf@pond.sub.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/28.2 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-Scanned-By: MIMEDefang 3.1 on 10.11.54.7 Received-SPF: pass client-ip=170.10.129.124; envelope-from=armbru@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 Juan Quintela writes: > Markus Armbruster wrote: >> The QEMUFileHooks methods don't come with a written contract. Digging >> through the code calling them, we find: >> >> * save_page(): >> >> Negative values RAM_SAVE_CONTROL_DELAYED and >> RAM_SAVE_CONTROL_NOT_SUPP are special. Any other negative value is >> an unspecified error. >> >> qemu_rdma_save_page() returns -EIO or rdma->error_state on error. I >> believe the latter is always negative. Nothing stops either of them >> to clash with the special values, though. Feels unlikely, but fix >> it anyway to return only the special values and -1. >> >> * before_ram_iterate(), after_ram_iterate(): >> >> Negative value means error. qemu_rdma_registration_start() and >> qemu_rdma_registration_stop() comply as far as I can tell. Make >> them comply *obviously*, by returning -1 on error. >> >> * hook_ram_load: >> >> Negative value means error. rdma_load_hook() already returns -1 on >> error. Leave it alone. >> >> Signed-off-by: Markus Armbruster >> Reviewed-by: Li Zhijian > > Reviewed-by: Juan Quintela > > Changed idea. Will include this and rebase mines on top. Thanks!