On Fri, Aug 31, 2012 at 01:29:46PM -0700, Alexander Graf wrote: > On 31.08.2012, at 12:15, Jason Baron <jba...@redhat.com> wrote: > > > On Fri, Aug 31, 2012 at 12:04:59PM -0700, Alexander Graf wrote: > >> 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. > >>>>> > >>>>> 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. > >>>>> > >>>>> I believe this change brings qemu into ahci 1.3 specification > >>>>> compliance. > >>>>> > >>>>> Section 10.4.3 HBA Reset: > >>>>> > >>>>> " > >>>>> 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. > >>>>> " > >>>>> > >>>>> I've also re-tested Fedora 16 and 17 to verify that they continue to > >>>>> work with > >>>>> this change. > >>>>> > >>>>> Signed-off-by: Jason Baron <jba...@redhat.com> > >>>>> --- > >>>>> hw/ide/ahci.c | 1 + > >>>>> 1 files changed, 1 insertions(+), 0 deletions(-) > >>>>> > >>>>> 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 = 0; > >>>>> pr->irq_mask = 0; > >>>>> pr->scr_ctl = 0; > >>>>> + pr->cmd = 0; > >>>>> ahci_reset_port(s, i); > >>>>> } > >>>>> } > >>>>> > >>>> > >>>> In ahci_init() we have: > >>>> > >>>> ad->port_regs.cmd = PORT_CMD_SPIN_UP | PORT_CMD_POWER_ON; > >>>> > >>>> 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. > >>>> > >>> > >>> Good catch. I just tried out the following instead in ahci_reset(): > >>> > >>> pr->cmd = PORT_CMD_SPIN_UP | PORT_CMD_POWER_ON; > >>> > >>> 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? > >> > >> > > > > Actually, we don't call reset on init. I'm thinking for 1.2, we can just > > add the fix to the reset path, and as Kevin suggested in 1.3, we will > > look to add a call to ahci_reset() in the init path. > > We register the reset handler as generic reset path, no? It should be called > on machine init then. Every reset handler gets called on machine boot. >
what about hotplug? There we call init, but not reset? -Jason
