[Qemu-devel] [PATCH] ahci: Fix non-NCQ accesses for LBA > 16bits

[Alexander Graf <agraf@suse.de>]

AHCI provides two ways of reading/writing data:

 1) NCQ
 2) ATA commands with the LBA in the command FIS

In the second code path, we didn't handle any LBAs that were bigger than
16 bits, so whenever a guest that used high LBA numbers wanted to access
data, the LBA got truncated down to 16 bits, giving the guest garbage.

This patch adds support for LBAs higher than 16 bits. I've tested that it
works just fine with SeaBIOS and Linux guests. This patch also unbreaks
the often reported grub errors people have seen with AHCI.

Signed-off-by: Alexander Graf <agraf@suse.de>
---
 hw/ide/ahci.c |    9 +++++++--
 1 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/hw/ide/ahci.c b/hw/ide/ahci.c
index c6e0c77..bc5c553 100644
--- a/hw/ide/ahci.c
+++ b/hw/ide/ahci.c
@@ -884,8 +884,13 @@ static int handle_cmd(AHCIState *s, int port, int slot)
         }
 
         if (ide_state->drive_kind != IDE_CD) {
-            ide_set_sector(ide_state, (cmd_fis[6] << 16) | (cmd_fis[5] << 8) |
-                           cmd_fis[4]);
+            ide_set_sector(ide_state, ((uint64_t)cmd_fis[10] << 40)
+                                    | ((uint64_t)cmd_fis[9] << 32)
+                                    | ((uint64_t)cmd_fis[8] << 24)
+                                    | ((uint64_t)(cmd_fis[7] & 0xf) << 24)
+                                    | ((uint64_t)cmd_fis[6] << 16)
+                                    | ((uint64_t)cmd_fis[5] << 8)
+                                    | cmd_fis[4]);
         }
 
         /* Copy the ACMD field (ATAPI packet, if any) from the AHCI command
-- 
1.6.0.2