From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1KyOPf-0002pu-Ui for qemu-devel@nongnu.org; Fri, 07 Nov 2008 05:18:00 -0500 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1KyOPb-0002pF-S7 for qemu-devel@nongnu.org; Fri, 07 Nov 2008 05:17:57 -0500 Received: from [199.232.76.173] (port=47072 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1KyOPa-0002ot-LN for qemu-devel@nongnu.org; Fri, 07 Nov 2008 05:17:54 -0500 Received: from qw-out-1920.google.com ([74.125.92.149]:8707) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1KyOPa-0004Hu-T1 for qemu-devel@nongnu.org; Fri, 07 Nov 2008 05:17:55 -0500 Received: by qw-out-1920.google.com with SMTP id 5so798274qwc.4 for ; Fri, 07 Nov 2008 02:17:53 -0800 (PST) Message-ID: <5d6222a80811070217h389b1c4eu38062b4582c04236@mail.gmail.com> Date: Fri, 7 Nov 2008 08:17:52 -0200 From: "Glauber Costa" Subject: Re: [Qemu-devel] vga slow with -enable-kvm In-Reply-To: <491407E9.4040506@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <491407E9.4040506@redhat.com> Reply-To: qemu-devel@nongnu.org List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org On Fri, Nov 7, 2008 at 7:18 AM, Gerd Hoffmann wrote: > Hi, > > The vga display is very slow when using latest svn with kvm enabled. > Just try to boot any linux kernel with vesafb enabled (vga=0x314 for > 800x600@16), enjoy watching the boot messages scroll. Booting without > kvm enabled is *faster*. > > Feels like every single screen access is trapped or something like that. > kvm_stat confirms that, there are tons of mmio exits: The vga optimization is supposed to fix this. I noticed this too, and maybe there's something wrong per se. But since the result with the optimization was pretty decent, I honestly didn't cared. > > [root@zweiblum ~]# kvm_stat -1 > efer_reload 0 0 > exits 98234706 132054 > fpu_reload 6330433 0 > halt_exits 104372 0 > halt_wakeup 0 0 > host_state_reload 96499874 132038 > hypercalls 0 0 > insn_emulation 94632076 129954 > insn_emulation_fail 0 0 > invlpg 0 0 > io_exits 2627489 1653 > irq_exits 239675 397 > irq_window 11138 14 > largepages 0 0 > mmio_exits 93583132 129946 > mmu_cache_miss 38079 0 > mmu_flooded 37708 0 > mmu_pde_zapped 35810 0 > mmu_pte_updated 588299 0 > mmu_pte_write 647324 0 > mmu_recycled 0 0 > mmu_shadow_zapped 48191 0 > pf_fixed 1211070 1 > pf_guest 109462 0 > remote_tlb_flush 0 0 > request_irq 0 0 > signal_exits 164181 402 > tlb_flush 728218 44 > > cheers, > Gerd > > > -- Glauber Costa. "Free as in Freedom" http://glommer.net "The less confident you are, the more serious you have to act."