Am 24.08.2012 um 07:18 schrieb Luiz Capitulino <[email protected]>:
> On Thu, 23 Aug 2012 17:09:25 -0400 > Jason Baron <[email protected]> wrote: > >> 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. > > I've tested this but unfortunately it doesn't fix the issues I'm getting with > OpenBSD 5.1 and NetBSD 5.1 as reported here (section 'master with ahci'): > > http://lists.gnu.org/archive/html/qemu-devel/2012-08/msg03329.html > > PS: Those could be kernel issues, of course. The BSDs already fail in detecting the cotroller as a whole, right? Not just disks on it. Alex > >> >> 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 <[email protected]> >> --- >> 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); >> } >> } >
