From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from [140.186.70.92] (port=33058 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1PqKpw-00018E-9J for qemu-devel@nongnu.org; Fri, 18 Feb 2011 02:33:09 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1PqKpr-0006hO-HH for qemu-devel@nongnu.org; Fri, 18 Feb 2011 02:33:08 -0500 Received: from chello084112167138.7.11.vie.surfer.at ([84.112.167.138]:60332 helo=wiesinger.com) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1PqKpr-0006gC-3u for qemu-devel@nongnu.org; Fri, 18 Feb 2011 02:33:03 -0500 Date: Fri, 18 Feb 2011 08:32:17 +0100 (CET) From: Gerhard Wiesinger Subject: Re: [Qemu-devel] Re: QEMU-KVM and video performance - Update In-Reply-To: <4BEA4D36.3020608@redhat.com> Message-ID: References: <4BCEBE5C.4020404@redhat.com> <20100421183357.GK27575@shareable.org> <4BCF6699.2060201@redhat.com> <4BCFF4B5.7010302@redhat.com> <4BE7B6A9.8060007@redhat.com> <4BEA4D36.3020608@redhat.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Avi Kivity , seabios@seabios.org, qemu-devel@nongnu.org, kvm@vger.kernel.org Cc: Jan Kiszka , Kevin O'Connor Hello, Some update on this issue, archive: http://www.mail-archive.com/kvm@vger.kernel.org/msg32600.html Seems to be that cirrus VGA is now ok (>1000MB/s up to 2000MB/s). But cirrus has only 320x200x256colors (Mode 13h) mode implemented in VESA BIOS. VMWare and std VGA still have the performance issue. I guess improvement is related to the following commit: http://git.kernel.org/?p=virt/kvm/qemu-kvm.git;a=commitdiff;h=0d14905b5eb8aa1c2e195e13478bb7c74e1776db Especially i guess the change in hw/cirrus_vga.c. Any idea how to fix: 1.) More VESA modes in cirrus VGA (is VESA emulation done by Seabios or by KVM cirrus BIOS?) 2.) fix in VMWare and std VGA modes the performance, too Versions are latest dev versions of KVM user part and Seabios from GIT. Thnx. Ciao, Gerhard -- http://www.wiesinger.com/ On Wed, 12 May 2010, Avi Kivity wrote: > On 05/12/2010 09:14 AM, Gerhard Wiesinger wrote: >> On Mon, 10 May 2010, Avi Kivity wrote: >> >>> On 05/09/2010 10:35 PM, Gerhard Wiesinger wrote: >>>>>> >>> >>> For 256 color more the first priority is to find out why direct mapping is >>> not used. I'd suggest tracing the code that makes this decision (in >>> hw/*vga.c) and seeing if it's right or not. >> >> I think this is because A000 is not initialized for KVM (see log below and >> logging patch attached). > > Why isn't it initialized? > > Did the guest configure things such as it is impossible to map it directly? > Or does the configuration allow direct mapping and qemu incorrectly decides > that it cannot direct map? > > Best would be to print out all the configuration registers and interpret them > according to the specification. > > >> >> vga_dirty_log_start >> vga_dirty_log_start_mapping_lfb_vram_mapped, start=0x000A0000, >> len=0x00008000 >> BUG: kvm_dirty_pages_log_change: invalid parameters >> 00000000000a0000-00000000000a7fff > > Why does this happen? > > -- > Do not meddle in the internals of kernels, for they are subtle and quick to > panic. > > >