From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: kvm-27 vs 28 I/O speed Date: Fri, 13 Jul 2007 16:41:36 +0300 Message-ID: <46978110.5090303@qumranet.com> References: <1183748857.10287.198.camel@localhost> <46909CFD.9050806@qumranet.com> <1184013180.10287.278.camel@localhost> <46931CC9.8060106@qumranet.com> <1184180092.26210.49.camel@localhost> <4695BE06.6060609@qumranet.com> <1184263854.26210.89.camel@localhost> <46976EA7.2020202@qumranet.com> <68676e00707130627p32a43a63l3c6fe647242ec3e@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: kvm-devel To: Luca Return-path: In-Reply-To: <68676e00707130627p32a43a63l3c6fe647242ec3e-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: kvm-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org Errors-To: kvm-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Id: kvm.vger.kernel.org Luca wrote: > On 7/13/07, Avi Kivity wrote: >> Dave Hansen wrote: >> > On Thu, 2007-07-12 at 08:37 +0300, Avi Kivity wrote: >> > >> >> Can you confirm it by backing out that one patch? >> >> >> > >> > Do you know the git commit id by chance? >> > >> > -- Dave >> > >> > >> commit 55a3212bc2f5ecddcd4c5cdf2bfb37ad71e45ff2 >> Author: Luca Tettamanti >> Date: Tue Jun 5 14:47:33 2007 +0300 >> >> kvm: qemu: initialize ata ports as enabled >> >> this allows libata to see the qemu ata ports. >> >> diff --git a/qemu/hw/ide.c b/qemu/hw/ide.c >> index 190f074..ddfb9bc 100644 >> --- a/qemu/hw/ide.c >> +++ b/qemu/hw/ide.c >> @@ -2586,6 +2586,8 @@ static void piix3_reset(PCIIDEState *d) >> pci_conf[0x06] = 0x80; /* FBC */ >> pci_conf[0x07] = 0x02; // PCI_status_devsel_medium >> pci_conf[0x20] = 0x01; /* BMIBA: 20-23h */ >> + pci_conf[0x41] = 0x80; // enable port 0 >> + pci_conf[0x43] = 0x80; // enable port 1 >> } >> >> void pci_piix_ide_init(PCIBus *bus, BlockDriverState **hd_table, int >> devfn) >> >> >> I was unable to reproduce this on a FC6 i386 guest. > > Hum... I assume the FC6 is using the "old" IDE driver, yes? I can't > see why that patch should matter though... if those bits are not set > then the IDE controller is not decoding the commands (on real hw). > I tested FC6 i386 about found no difference with or without the patch. Dave, can you diff the guest dmesg with kvm-27 and kvm-28 userspace? Maybe that will tell us something. -- Do not meddle in the internals of kernels, for they are subtle and quick to panic. ------------------------------------------------------------------------- This SF.net email is sponsored by DB2 Express Download DB2 Express C - the FREE version of DB2 express and take control of your XML. No limits. Just data. Click to get it now. http://sourceforge.net/powerbar/db2/