On Tue, Dec 12, 2017 at 5:35 PM, Kristina Martsenko
<kristina.martsenko@xxxxxxx> wrote:
> Hi Christoffer,
>
> On 12/12/17 12:50, Christoffer Dall wrote:
>> From: Kristina Martsenko <kristina.martsenko@xxxxxxx>
>>
>> Commit 26aa7b3b1c0fb3f1a6176a0c1847204ef4355693 upstream.
>>
>> VTTBR_BADDR_MASK is used to sanity check the size and alignment of the
>> VTTBR address. It seems to currently be off by one, thereby only
>> allowing up to 47-bit addresses (instead of 48-bit) and also
>> insufficiently checking the alignment. This patch fixes it.
>>
>> As an example, with 4k pages, before this patch we have:
>>
>> PHYS_MASK_SHIFT = 48
>> VTTBR_X = 37 - 24 = 13
>> VTTBR_BADDR_SHIFT = 13 - 1 = 12
>> VTTBR_BADDR_MASK = ((1 << 35) - 1) << 12 = 0x00007ffffffff000
>>
>> Which is wrong, because the mask doesn't allow bit 47 of the VTTBR
>> address to be set, and only requires the address to be 12-bit (4k)
>> aligned, while it actually needs to be 13-bit (8k) aligned because we
>> concatenate two 4k tables.
>>
>> With this patch, the mask becomes 0x0000ffffffffe000, which is what we
>> want.
>>
>> Fixes: 0369f6a34b9f ("arm64: KVM: EL2 register definitions")
>> Cc: <stable@xxxxxxxxxxxxxxx> # 3.11.x
>> Reviewed-by: Suzuki K Poulose <suzuki.poulose@xxxxxxx>
>> Reviewed-by: Christoffer Dall <christoffer.dall@xxxxxxxxxx>
>> Signed-off-by: Kristina Martsenko <kristina.martsenko@xxxxxxx>
>> Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx>
>> Signed-off-by: Christoffer Dall <christoffer.dall@xxxxxxxxxx>
>> ---
>> arch/arm64/include/asm/kvm_arm.h | 3 +--
>> 1 file changed, 1 insertion(+), 2 deletions(-)
>
> Not sure if I'm missing something, but it seems like this patch (and the
> v3.18 one) were already applied to the stable trees. It's two of the
> arch/arm/ patches that failed to apply, not the arch/arm64/ ones.
>
You're not missing anything - I accidentally copied the commit id from
the e-mail that told me it successfully applied the patch, duh.
I'll fix the other one.
-Christoffer