From mboxrd@z Thu Jan  1 00:00:00 1970
From: Marc Zyngier <marc.zyngier@arm.com>
Subject: Re: [PATCH 4/4] ARM: KVM: fix use of S2_PGD_SIZE
Date: Tue, 30 Apr 2013 18:52:24 +0100
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Cc: linux-arm-kernel <linux-arm-kernel@lists.infradead.org>,
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To: Christoffer Dall <cdall@cs.columbia.edu>
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On 30/04/13 18:40, Christoffer Dall wrote:
> On Tue, Apr 30, 2013 at 7:17 AM, Marc Zyngier <marc.zyngier@arm.com> wrote:
>> S2_PGD_SIZE describe the number of pages a used by a stage-2 PGD,
>> not the size of the PGD.
>>
>> Fix the VM_BUG_ON() call that doesn't check much when S2_PGD_SIZE
>> is equal to 1.
>>
>> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
>> ---
>>  arch/arm/kvm/mmu.c | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/arch/arm/kvm/mmu.c b/arch/arm/kvm/mmu.c
>> index b978ebe..09ece5c 100644
>> --- a/arch/arm/kvm/mmu.c
>> +++ b/arch/arm/kvm/mmu.c
>> @@ -377,7 +377,7 @@ int kvm_alloc_stage2_pgd(struct kvm *kvm)
>>                 return -ENOMEM;
>>
>>         /* stage-2 pgd must be aligned to its size */
>> -       VM_BUG_ON((unsigned long)pgd & (S2_PGD_SIZE - 1));
>> +       VM_BUG_ON((unsigned long)pgd & (PAGE_SIZE * S2_PGD_SIZE - 1));
> 
> I think the define is broken and should be fixed and/or renamed instead.

To be fair, I wouldn't mind the whole check to be dropped altogether. If
__get_free_pages doesn't give you an aligned allocation, the whole
kernel is going the way of the dodo, and we shouldn't really care...

Your call, really.

	M.
-- 
Jazz is not dead. It just smells funny...