Re: [PATCH v9 1/8] KVM: arm/arm64: Share common code in user_mem_abort()

From: Suzuki K Poulose <suzuki.poulose@arm.com>
To: Christoffer Dall <christoffer.dall@arm.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>,
	kvmarm@lists.cs.columbia.edu, marc.zyngier@arm.com,
	will.deacon@arm.com, linux-kernel@vger.kernel.org,
	punitagrawal@gmail.com, linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH v9 1/8] KVM: arm/arm64: Share common code in user_mem_abort()
Date: Mon, 10 Dec 2018 10:26:42 +0000	[thread overview]
Message-ID: <525e88a4-b3af-3d7c-ac08-5461b8aa9e51@arm.com> (raw)
In-Reply-To: <20181210085616.GB30263@e113682-lin.lund.arm.com>

On 10/12/2018 08:56, Christoffer Dall wrote:
> On Mon, Dec 03, 2018 at 01:37:37PM +0000, Suzuki K Poulose wrote:
>> Hi Anshuman,
>>
>> On 03/12/2018 12:11, Anshuman Khandual wrote:
>>>
>>>
>>> On 10/31/2018 11:27 PM, Punit Agrawal wrote:
>>>> The code for operations such as marking the pfn as dirty, and
>>>> dcache/icache maintenance during stage 2 fault handling is duplicated
>>>> between normal pages and PMD hugepages.
>>>>
>>>> Instead of creating another copy of the operations when we introduce
>>>> PUD hugepages, let's share them across the different pagesizes.
>>>>
>>>> Signed-off-by: Punit Agrawal <punit.agrawal@arm.com>
>>>> Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
>>>> Cc: Christoffer Dall <christoffer.dall@arm.com>
>>>> Cc: Marc Zyngier <marc.zyngier@arm.com>
>>>> ---
>>>>   virt/kvm/arm/mmu.c | 49 ++++++++++++++++++++++++++++------------------
>>>>   1 file changed, 30 insertions(+), 19 deletions(-)
>>>>
>>>> diff --git a/virt/kvm/arm/mmu.c b/virt/kvm/arm/mmu.c
>>>> index 5eca48bdb1a6..59595207c5e1 100644
>>>> --- a/virt/kvm/arm/mmu.c
>>>> +++ b/virt/kvm/arm/mmu.c
>>>> @@ -1475,7 +1475,7 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
>>>>   			  unsigned long fault_status)
>>>>   {
>>>>   	int ret;
>>>> -	bool write_fault, exec_fault, writable, hugetlb = false, force_pte = false;
>>>> +	bool write_fault, exec_fault, writable, force_pte = false;
>>>>   	unsigned long mmu_seq;
>>>>   	gfn_t gfn = fault_ipa >> PAGE_SHIFT;
>>>>   	struct kvm *kvm = vcpu->kvm;
>>>> @@ -1484,7 +1484,7 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
>>>>   	kvm_pfn_t pfn;
>>>>   	pgprot_t mem_type = PAGE_S2;
>>>>   	bool logging_active = memslot_is_logging(memslot);
>>>> -	unsigned long flags = 0;
>>>> +	unsigned long vma_pagesize, flags = 0;
>>>
>>> A small nit s/vma_pagesize/pagesize. Why call it VMA ? Its implicit.
>>
>> May be we could call it mapsize. pagesize is confusing.
>>
> 
> I'm ok with mapsize.  I see the vma_pagesize name coming from the fact
> that this is initially set to the return value from vma_kernel_pagesize.
> 
> I have not problems with either vma_pagesize or mapsize.

Ok, I will retain the vma_pagesize to avoid unnecessary changes to the patch.

Thanks
Suzuki