Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Subject: Re: [PATCH 2/8] xen/balloon: Move common memory reservation routines
 to a module
From:   Oleksandr Andrushchenko <andr2000@gmail.com>
To:     Boris Ostrovsky <boris.ostrovsky@oracle.com>,
        xen-devel@lists.xenproject.org, linux-kernel@vger.kernel.org,
        dri-devel@lists.freedesktop.org, linux-media@vger.kernel.org,
        jgross@suse.com, konrad.wilk@oracle.com
Cc:     daniel.vetter@intel.com, dongwon.kim@intel.com,
        matthew.d.roper@intel.com,
        Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
References: <20180525153331.31188-1-andr2000@gmail.com>
 <20180525153331.31188-3-andr2000@gmail.com>
 <59ab73b0-967b-a82f-3b0d-95f1b0dc40a5@oracle.com>
 <89de7bdb-8759-419f-63bf-8ed0d57650f0@gmail.com>
 <edfa937b-3311-98db-2e6f-b4083598f796@oracle.com>
 <6ca7f428-eede-2c14-85fe-da4a20bcea0d@gmail.com>
 <5dd3378d-ac32-691e-1f80-7218a5d07fd6@oracle.com>
 <43c17501-8865-6e1f-1a92-d947755d8fa8@gmail.com>
 <c08c380d-17af-b668-acf2-8d8a94333aca@oracle.com>
 <b9046572-8802-b213-a74f-68f58a58ae6a@gmail.com>
Message-ID: <4d386f6f-5212-1e42-abf7-1913f6218f05@gmail.com>
Date:   Thu, 31 May 2018 17:29:09 +0300
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101
 Thunderbird/52.8.0
MIME-Version: 1.0
In-Reply-To: <b9046572-8802-b213-a74f-68f58a58ae6a@gmail.com>
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Transfer-Encoding: 8bit
Content-Language: en-US
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On 05/31/2018 10:51 AM, Oleksandr Andrushchenko wrote:
> On 05/30/2018 10:24 PM, Boris Ostrovsky wrote:
>> On 05/30/2018 01:46 PM, Oleksandr Andrushchenko wrote:
>>> On 05/30/2018 06:54 PM, Boris Ostrovsky wrote:
>>>>
>>>> BTW, I also think you can further simplify
>>>> xenmem_reservation_va_mapping_* routines by bailing out right away if
>>>> xen_feature(XENFEAT_auto_translated_physmap). In fact, you might even
>>>> make them inlines, along the lines of
>>>>
>>>> inline void xenmem_reservation_va_mapping_reset(unsigned long count,
>>>>                       struct page **pages)
>>>> {
>>>> #ifdef CONFIG_XEN_HAVE_PVMMU
>>>>      if (!xen_feature(XENFEAT_auto_translated_physmap))
>>>>          __xenmem_reservation_va_mapping_reset(...)
>>>> #endif
>>>> }
>>> How about:
>>>
>>> #ifdef CONFIG_XEN_HAVE_PVMMU
>>> static inline __xenmem_reservation_va_mapping_reset(struct page *page)
>>> {
>>> [...]
>>> }
>>> #endif
>>>
>>> and
>>>
>>> void xenmem_reservation_va_mapping_reset(unsigned long count,
>>>                       struct page **pages)
>>> {
>>> #ifdef CONFIG_XEN_HAVE_PVMMU
>>>      if (!xen_feature(XENFEAT_auto_translated_physmap)) {
>>>          int i;
>>>
>>>          for (i = 0; i < count; i++)
>>>              __xenmem_reservation_va_mapping_reset(pages[i]);
>>>      }
>>> #endif
>>> }
>>>
>>> This way I can use __xenmem_reservation_va_mapping_reset(page);
>>> instead of xenmem_reservation_va_mapping_reset(1, &page);
>>
>> Sure, this also works.
> Could you please take look at the patch attached if this is what we want?
Please ignore it, it is ugly ;)
I have implemented this as you suggested:

static inline void
xenmem_reservation_va_mapping_update(unsigned long count,
                      struct page **pages,
                      xen_pfn_t *frames)
{
#ifdef CONFIG_XEN_HAVE_PVMMU
     if (!xen_feature(XENFEAT_auto_translated_physmap))
         __xenmem_reservation_va_mapping_update(count, pages, frames);
#endif
}

>> -boris
>>
> Thank you,
> Oleksandr