From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:41911) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1T7WX4-000118-UR for qemu-devel@nongnu.org; Fri, 31 Aug 2012 15:05:32 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1T7WX3-0000cb-LM for qemu-devel@nongnu.org; Fri, 31 Aug 2012 15:05:30 -0400 Received: from cantor2.suse.de ([195.135.220.15]:33464 helo=mx2.suse.de) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1T7WX3-0000bn-BN for qemu-devel@nongnu.org; Fri, 31 Aug 2012 15:05:29 -0400 Mime-Version: 1.0 (Apple Message framework v1278) Content-Type: text/plain; charset=us-ascii From: Alexander Graf In-Reply-To: <20120831142305.GA12212@redhat.com> Date: Fri, 31 Aug 2012 12:04:59 -0700 Content-Transfer-Encoding: quoted-printable Message-Id: <128F51EA-270A-41FA-A284-530EB6599C41@suse.de> References: <201208232109.q7NL9P9t016424@int-mx09.intmail.prod.int.phx2.redhat.com> <50408E06.1070009@redhat.com> <20120831142305.GA12212@redhat.com> Subject: Re: [Qemu-devel] [PATCH] ahci: properly reset PxCMD on HBA reset List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Jason Baron Cc: Kevin Wolf , aliguori@us.ibm.com, mst@redhat.com, jan.kiszka@siemens.com, qemu-devel@nongnu.org, lcapitulino@redhat.com, yamahata@valinux.co.jp, alex.williamson@redhat.com, pbonzini@redhat.com, afaerber@suse.de, armbru@redhat.com On 31.08.2012, at 07:23, Jason Baron wrote: > On Fri, Aug 31, 2012 at 12:12:22PM +0200, Kevin Wolf wrote: >> Am 23.08.2012 23:09, schrieb Jason Baron: >>> While testing q35, I found that windows 7 (specifically, windows 7 = ultimate >>> with sp1 x64), wouldn't install because it can't find the cdrom or = disk drive. >>> The failure message is: 'A required cd/dvd device driver is missing. = If you >>> have a driver floppy disk, CD, DVD, or USB flash drive, please = insert it now.' >>> This can also be reproduced on piix by adding an ahci controller, = and >>> observing that windows 7 does not see any devices behind it. >>>=20 >>> The problem is that when windows issues a HBA reset, qemu does not = reset the >>> individual ports' PxCMD register. Windows 7 then reads back the = PxCMD register >>> and presumably assumes that the ahci controller has already been = initialized. >>> Windows then never sets up the PxIE register to enable interrupts, = and thus it >>> never gets irqs back when it sends ata device inquiry commands. >>>=20 >>> I believe this change brings qemu into ahci 1.3 specification = compliance. >>>=20 >>> Section 10.4.3 HBA Reset: >>>=20 >>> " >>> When GHC.HR is set to '1', GHC.AE, GHC.IE, the IS register, and all = port >>> register fields (except PxFB/PxFBU/PxCLB/PxCLBU) that are not HwInit = in the >>> HBA's register memory space are reset. >>> " >>>=20 >>> I've also re-tested Fedora 16 and 17 to verify that they continue to = work with >>> this change. >>>=20 >>> Signed-off-by: Jason Baron >>> --- >>> hw/ide/ahci.c | 1 + >>> 1 files changed, 1 insertions(+), 0 deletions(-) >>>=20 >>> diff --git a/hw/ide/ahci.c b/hw/ide/ahci.c >>> index 9fe89a5..06c236f 100644 >>> --- a/hw/ide/ahci.c >>> +++ b/hw/ide/ahci.c >>> @@ -1199,6 +1199,7 @@ void ahci_reset(AHCIState *s) >>> pr->irq_stat =3D 0; >>> pr->irq_mask =3D 0; >>> pr->scr_ctl =3D 0; >>> + pr->cmd =3D 0; >>> ahci_reset_port(s, i); >>> } >>> } >>>=20 >>=20 >> In ahci_init() we have: >>=20 >> ad->port_regs.cmd =3D PORT_CMD_SPIN_UP | PORT_CMD_POWER_ON; >>=20 >> Why is resetting to 0 in ahci_reset() correct? I think we can still = get >> this part committed for 1.2 after you either explain why 0 is right = or >> send a fixed version. >>=20 >=20 > Good catch. I just tried out the following instead in ahci_reset(): >=20 > pr->cmd =3D PORT_CMD_SPIN_UP | PORT_CMD_POWER_ON; >=20 > And it continues to make Windows7 find the ahci disks. I'd like to do = a > little more testing, but I will send an updated path. Since we reset on init, we can just shove it there completely, right? Alex