On 31.08.2012, at 13:54, Jason Baron <jba...@redhat.com> wrote:
> 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? Really? It would be broken then already, no? Alex > > -Jason
