From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Sebastian Herbszt" Subject: Re: [Qemu-devel] Re: Question about KVM and PC speaker Date: Sun, 10 May 2009 00:21:27 +0200 Message-ID: References: <49EF69BC.90300@gmx.de> <49F01C8D.1010203@web.de> <20090423083252.GB5277@const.bordeaux.inria.fr> <49F031C2.5000204@siemens.com> <20090423092546.GF5277@const.bordeaux.inria.fr> <49F035E7.5080906@siemens.com> <49F03A00.8060502@redhat.com> <49F0430A.8010300@siemens.com> <49FF1919.1030909@gmx.de> <49FF5033.1050402@web.de> <20090504205618.GP5889@const.famille.thibault.fr> <49FF5777.8070704@web.de> <4A006268.6040006@linux-fuer-blinde.de> <3D0ED7CD58CF4D37904670A5A85AE2C7@FSCPC> <4A0167B7.2050200@siemens.com> <4A0297D2.4040009@siemens.com> Mime-Version: 1.0 Content-Type: text/plain; format=flowed; charset="iso-8859-1"; reply-type=original Content-Transfer-Encoding: 7bit Cc: "Simon Bienlein" , , To: "Jan Kiszka" , "Volker Ruppert" Return-path: Received: from mail.gmx.net ([213.165.64.20]:41276 "HELO mail.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1752560AbZEIWXg (ORCPT ); Sat, 9 May 2009 18:23:36 -0400 In-Reply-To: <4A0297D2.4040009@siemens.com> Sender: kvm-owner@vger.kernel.org List-ID: Jan Kiszka wrote: > Sebastian Herbszt wrote: >> Jan Kiszka wrote: >>> Sebastian Herbszt wrote: >>>> Simon Bienlein wrote: >>>>> Is a support for BIOS worked on right now? >>>> >>>> The vgabios (vgabios.c) has a "FIXME should beep". Volker, do you plan >>>> to fix this? >>>> >>>> Which frequency should be used for the beep? Which delay? >>> >>> I would try 1 KHz and some hundred milliseconds. >> >> I just looked at some vga bios and it uses about 896,45 Hz. >> >>>> Getting a delay using "inb(0x61) & 0x10" is still a no go on qemu, >>>> right? >>> >>> Looks like (should be far too inaccurate for longer delays). What about >>> 0x40:0x6c, the BIOS' daily timer counter? >> >> The bios i looked at used the refresh request port 0x61. This is >> supported by bochs and >> there is also a patch for qemu to replace the dummy [1]. The rombios >> uses this to provide >> INT 15h AH=86h functionality; this is likely broken with the dummy code >> in qemu. > > I see no problem with improving qemu's emulation accuracy this way a > bit. But I wouldn't built new delay implementations on top of it, > specifically if the code is in fact aware of running over a hypervisor. > Such micro-timings are far too inaccurate for longer delays in an > environment where you cannot be sure of running all the time during that > period. Volker, mind to resubmit the patch once again? >> Anyway, using "timer ticks since midnight" should be possible (INT 08h >> handler is set up >> before vga bios is called). I have implemented the beep for vgabios-6b and it works on bochs but fails on qemu. With "-soundhw pcspk" i should hear it thru the hosts pc speaker, right? - Sebastian