From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:60914) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aqjCn-00065u-Gg for qemu-devel@nongnu.org; Thu, 14 Apr 2016 11:29:18 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1aqjCi-0002ks-4R for qemu-devel@nongnu.org; Thu, 14 Apr 2016 11:29:17 -0400 Received: from mx2.suse.de ([195.135.220.15]:55410) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aqjCh-0002kT-Rb for qemu-devel@nongnu.org; Thu, 14 Apr 2016 11:29:12 -0400 References: <1460643912-244245-1-git-send-email-agraf@suse.de> <1460647067.18572.31.camel@redhat.com> From: Alexander Graf Message-ID: <570FB743.6060808@suse.de> Date: Thu, 14 Apr 2016 17:29:07 +0200 MIME-Version: 1.0 In-Reply-To: <1460647067.18572.31.camel@redhat.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH] hid: Extend the event queue size to 1024 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Gerd Hoffmann Cc: qemu-devel@nongnu.org, Juan Quintela , Dinar Valeev , Dirk Mueller On 04/14/2016 05:17 PM, Gerd Hoffmann wrote: > On Do, 2016-04-14 at 16:25 +0200, Alexander Graf wrote: >> We can currently buffer up to 16 events in our event queue for input >> devices. While it sounds like 16 events backlog for everyone should >> be enough, our automated testing tools (OpenQA) manage to easily >> type faster than our guests can handle. > IMO you should fix OpenQA to type slower then. > > Real hardware is made for human typing speeds. qemu emulates real > hardware. Typing insane fast is going to cause problems because the > hardware interfaces are not designed for that. > > Note the ps/2 keyboard has only a 16 byte queue too. Used to be 256 > bytes, but that caused problems because this diverges from real hardware > (see commit 2858ab09e6f708e381fc1a1cc87e747a690c4884 for all the > details). > > Note that the generic input code has support for slow typing already > (see qemu_input_event_send_key_delay in ui/input.c). That queue will > (a) work for all keyboard devices and (b) isn't visible to the guest, so > using that might be a reasonable option if you can't put the delay logic > into OpenQA. How to you feed the guest with keystrokes? monitor? vnc? It used to type via the monitor, but these days everything goes via vnc. Vnc already uses qemu_input_event_send_key_delay today, so I'm not sure where things fall apart. Alex