From mboxrd@z Thu Jan  1 00:00:00 1970
From: Razvan Cojocaru <rcojocaru@bitdefender.com>
Subject: Re: [PATCH] x86/arm/mm: use gfn instead of pfn in
 p2m_get_mem_access/p2m_set_mem_access
Date: Thu, 25 Jun 2015 14:35:31 +0300
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To: Ian Campbell <ian.campbell@citrix.com>, Vitaly Kuznetsov <vkuznets@redhat.com>, Tamas K Lengyel <tlengyel@novetta.com>
Cc: Keir Fraser <keir@xen.org>, Andrew Cooper <andrew.cooper3@citrix.com>, Tim Deegan <tim@xen.org>, xen-devel@lists.xen.org, Stefano Stabellini <stefano.stabellini@citrix.com>, Jan Beulich <JBeulich@suse.com>
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On 06/25/2015 01:27 PM, Ian Campbell wrote:
> On Tue, 2015-06-23 at 18:25 +0200, Vitaly Kuznetsov wrote:
>> "Jan Beulich" <JBeulich@suse.com> writes:
>>
>>>>>> On 26.05.15 at 15:32, <vkuznets@redhat.com> wrote:
>>>> --- a/xen/arch/arm/p2m.c
>>>> +++ b/xen/arch/arm/p2m.c
>>>> @@ -1709,9 +1709,9 @@ bool_t p2m_mem_access_check(paddr_t gpa, vaddr_t gla, 
>>>> const struct npfec npfec)
>>>>  
>>>>  /*
>>>>   * Set access type for a region of pfns.
>>>> - * If start_pfn == -1ul, sets the default access type.
>>>> + * If start_gfn == -1ul, sets the default access type.
>>>>   */
>>>> -long p2m_set_mem_access(struct domain *d, unsigned long pfn, uint32_t nr,
>>>> +long p2m_set_mem_access(struct domain *d, unsigned long start_gfn, uint32_t nr,
>>>>                          uint32_t start, uint32_t mask, xenmem_access_t access)
>>>>  {
>>>>      struct p2m_domain *p2m = p2m_get_hostp2m(d);
>>>> @@ -1752,14 +1752,15 @@ long p2m_set_mem_access(struct domain *d, unsigned long pfn, uint32_t nr,
>>>>      p2m->mem_access_enabled = true;
>>>>  
>>>>      /* If request to set default access. */
>>>> -    if ( pfn == ~0ul )
>>>> +    if ( start_gfn == ~0ul )
>>>>      {
>>>>          p2m->default_access = a;
>>>>          return 0;
>>>>      }
>>>>  
>>>>      rc = apply_p2m_changes(d, MEMACCESS,
>>>> -                           pfn_to_paddr(pfn+start), pfn_to_paddr(pfn+nr),
>>>> +                           pfn_to_paddr(start_gfn + start),
>>>
>>> Particularly due to this expression I'm not really happy about the
>>> start_ prefix that you're adding here, but I'll let the maintainers
>>> of the respective pieces of code decide if they're happy with it.
>>
>> Sorry for the ping but it has been almost one month...
> 
> Sorry, I must have missed this one, pinging was absolutely the right
> thing to do (after a week or two would have been fine, no need to wait a
> month).
> 
> I'm not super keen on the start_ prefix either, but I would prefer
> consistency between arm and x86 here more than I object to the prefix.
> IOW my preference would be to drop it everywhere, but if x86 folks
> prefer to keep it then I don't mind but ARM should keep it too.
> 
> I've also copied the (new) mem access maintainers in case they have an
> opinion.

FWIW, I agree with you and Jan, the start_ prefix makes it a bit
confusing. And again FWIW, I have no problem with this being changed for
both x86 and ARM.


Regards,
Razvan