From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1O4epy-0000dC-9z for qemu-devel@nongnu.org; Wed, 21 Apr 2010 14:39:50 -0400 Received: from [140.186.70.92] (port=53615 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1O4epw-0000bK-NN for qemu-devel@nongnu.org; Wed, 21 Apr 2010 14:39:49 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.69) (envelope-from ) id 1O4epv-0001ns-Ep for qemu-devel@nongnu.org; Wed, 21 Apr 2010 14:39:48 -0400 Received: from mail2.shareable.org ([80.68.89.115]:33930) by eggs.gnu.org with esmtp (Exim 4.69) (envelope-from ) id 1O4epv-0001nd-A7 for qemu-devel@nongnu.org; Wed, 21 Apr 2010 14:39:47 -0400 Date: Wed, 21 Apr 2010 19:39:31 +0100 From: Jamie Lokier Subject: Re: [Qemu-devel] Re: QEMU-KVM and video performance Message-ID: <20100421183930.GL27575@shareable.org> References: <4BCEBE5C.4020404@redhat.com> <20100421100840.GF13114@shareable.org> <4BCED82C.9020702@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4BCED82C.9020702@redhat.com> List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Avi Kivity Cc: Gerhard Wiesinger , qemu-devel@nongnu.org, kvm@vger.kernel.org Avi Kivity wrote: > Writes to vga in 16-color mode don't change set a memory location to a > value, instead they change multiple memory locations. While code is just writing to the VGA memory, not reading(*) and not touching the VGA I/O register that control the write latches, is it possible in principle to swizzle the format around in memory to make regular writes work? (*) Reading should be ok for some settings of the write latches, I think. I wonder if guests of interest behave like that. > >Is this a case where TCG would run significantly faster for code blocks > >that have been detected to access the VGA memory? > > Yes. $ date Wed Apr 21 19:37:38 2015 $ modprobe ktcg ;-) -- Jamie