diff mbox

[PULL,1/1] ahci: advertise HOST_CAP_64

Message ID 20170210164825.9241-2-jsnow@redhat.com
State New
Headers show

Commit Message

John Snow Feb. 10, 2017, 4:48 p.m. UTC 
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>
---
 hw/ide/ahci.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
diff mbox

Patch

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;