On 03/20/2017 07:08 PM, Michael Roth wrote:
> From: Ladi Prosek <lprosek@redhat.com>
>
> The AHCI emulation code supports 64-bit addressing and should advertise this
> fact in the Host Capabilities register. Both Linux and Windows drivers test
> this bit to decide if the upper 32 bits of various registers may be written
> to, and at least some versions of Windows have a bug where DMA is attempted
> with an address above 4GB but, in the absence of HOST_CAP_64, the upper 32
> bits are left unititialized which leads to a memory corruption.
>
> [Maintainer edit:
>
> This fixes https://bugzilla.redhat.com/show_bug.cgi?id=1411105,
> which affects Windows Server 2008 SP2 in some cases.]
>
> Signed-off-by: Ladi Prosek <lprosek@redhat.com>
> Message-id: 1484305370-6220-1-git-send-email-lprosek@redhat.com
> [Amended commit message --js]
> Signed-off-by: John Snow <jsnow@redhat.com>
>
> (cherry picked from commit 98cb5dccb192b0082626080890dac413473573c6)
> Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
> ---
> hw/ide/ahci.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/hw/ide/ahci.c b/hw/ide/ahci.c
> index 3c19bda..6a17acf 100644
> --- a/hw/ide/ahci.c
> +++ b/hw/ide/ahci.c
> @@ -488,7 +488,7 @@ static void ahci_reg_init(AHCIState *s)
> s->control_regs.cap = (s->ports - 1) |
> (AHCI_NUM_COMMAND_SLOTS << 8) |
> (AHCI_SUPPORTED_SPEED_GEN1 << AHCI_SUPPORTED_SPEED) |
> - HOST_CAP_NCQ | HOST_CAP_AHCI;
> + HOST_CAP_NCQ | HOST_CAP_AHCI | HOST_CAP_64;
>
> s->control_regs.impl = (1 << s->ports) - 1;
>
>
A reminder that if this is backported to 2.8.1, that you will need to
include the relevant seaBIOS fixes as well. Otherwise, rebooting under
that firmware breaks!
--js