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

[Alexander Graf]

On 18.05.2011, at 21:16, Jan Kiszka wrote:

> On 2011-05-18 14:48, Alexander Graf wrote:
>> 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.
> 
> Cool! I actually had such a guest as well, but I didn't manage to look
> closer so far. Now this patch cures it.

Heh, yeah. Only costed me 2 days of my life - sigh :)


Alex