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=-6.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no 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 DB33AC4338F for ; Mon, 9 Aug 2021 09:56:53 +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 588D760F35 for ; Mon, 9 Aug 2021 09:56:53 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 588D760F35 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=nongnu.org Received: from localhost ([::1]:48286 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1mD21c-00052y-B8 for qemu-devel@archiver.kernel.org; Mon, 09 Aug 2021 05:56:52 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:51406) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mD1xA-0005DE-1a for qemu-devel@nongnu.org; Mon, 09 Aug 2021 05:52:17 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:40023) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mD1x7-0004Jp-0q for qemu-devel@nongnu.org; Mon, 09 Aug 2021 05:52:14 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1628502731; 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=eIquUYmi3icr0WqQRwVBRKwa4ztNrlaPfFjqjv7aLZk=; b=bhXnzzWDSSDXTnmKWI5M85suPTH9prfd6m9s8gDZlR6PjfAHzl5/J1yL/Sv7KVJPJa4J1S P8Jrav6QaYZr1wEJ2Nxbf/2q4672VkLWwzjGl5LXA+ly69mhRFyKiZdIKRLP220QXwflaR hAT/wH9kJoxknnIPdmcslRPHVzOdnWE= 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-312-9ZI3mVCzMuaIjVLRODbcYQ-1; Mon, 09 Aug 2021 05:52:10 -0400 X-MC-Unique: 9ZI3mVCzMuaIjVLRODbcYQ-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 74E35100E421; Mon, 9 Aug 2021 09:52:09 +0000 (UTC) Received: from sirius.home.kraxel.org (unknown [10.39.193.3]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 3C97D5D6B1; Mon, 9 Aug 2021 09:52:09 +0000 (UTC) Received: by sirius.home.kraxel.org (Postfix, from userid 1000) id 874271800981; Mon, 9 Aug 2021 11:52:07 +0200 (CEST) Date: Mon, 9 Aug 2021 11:52:07 +0200 From: Gerd Hoffmann To: Volker =?utf-8?Q?R=C3=BCmelin?= Subject: Re: [PATCH 2/3] ps2: use a separate keyboard command reply queue Message-ID: <20210809095207.w4ps4zusyreqrrlc@sirius.home.kraxel.org> References: <4d1c8467-d976-2c0f-ba54-c767df7b8fe7@t-online.de> <20210807121202.6294-2-vr_qemu@t-online.de> MIME-Version: 1.0 In-Reply-To: <20210807121202.6294-2-vr_qemu@t-online.de> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=kraxel@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=kraxel@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -34 X-Spam_score: -3.5 X-Spam_bar: --- X-Spam_report: (-3.5 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.707, 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_H2=-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: Philippe =?utf-8?Q?Mathieu-Daud=C3=A9?= , qemu-devel@nongnu.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Hi, > A PS/2 keyboard has a separate command reply queue that is > independant of the key queue. This prevents that command replies > and keyboard input mix. Keyboard command replies take precedence > over queued keystrokes. A new keyboard command removes any > remaining command replies from the command reply queue. > > Implement a separate keyboard command reply queue and clear the > command reply queue before command execution. This brings the > PS/2 keyboard emulation much closer to a real PS/2 keyboard. It seems you place both queues in the existing 256-byte buffer, probably to avoid breaking live migration. Could you explain the logic a bit more, how the three pointers q->*ptr variables play together here? thanks, Gerd