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] [v2] xen: avoid link error on ARM
To:     Boris Ostrovsky <boris.ostrovsky@oracle.com>,
        Arnd Bergmann <arnd@arndb.de>
Cc:     Stefano Stabellini <sstabellini@kernel.org>,
        Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>,
        Paul Durrant <paul.durrant@citrix.com>,
        linux-kernel@vger.kernel.org, xen-devel@lists.xenproject.org
References: <20190305133057.3998926-1-arnd@arndb.de>
 <35654e1a-d066-0581-749f-7e3b65023988@oracle.com>
From:   Juergen Gross <jgross@suse.com>
Openpgp: preference=signencrypt
Autocrypt: addr=jgross@suse.com; prefer-encrypt=mutual; keydata=
 xsBNBFOMcBYBCACgGjqjoGvbEouQZw/ToiBg9W98AlM2QHV+iNHsEs7kxWhKMjrioyspZKOB
 ycWxw3ie3j9uvg9EOB3aN4xiTv4qbnGiTr3oJhkB1gsb6ToJQZ8uxGq2kaV2KL9650I1SJve
 dYm8Of8Zd621lSmoKOwlNClALZNew72NjJLEzTalU1OdT7/i1TXkH09XSSI8mEQ/ouNcMvIJ
 NwQpd369y9bfIhWUiVXEK7MlRgUG6MvIj6Y3Am/BBLUVbDa4+gmzDC9ezlZkTZG2t14zWPvx
 XP3FAp2pkW0xqG7/377qptDmrk42GlSKN4z76ELnLxussxc7I2hx18NUcbP8+uty4bMxABEB
 AAHNHkp1ZXJnZW4gR3Jvc3MgPGpncm9zc0BzdXNlLmRlPsLAeQQTAQIAIwUCU4xw6wIbAwcL
 CQgHAwIBBhUIAgkKCwQWAgMBAh4BAheAAAoJELDendYovxMvi4UH/Ri+OXlObzqMANruTd4N
 zmVBAZgx1VW6jLc8JZjQuJPSsd/a+bNr3BZeLV6lu4Pf1Yl2Log129EX1KWYiFFvPbIiq5M5
 kOXTO8Eas4CaScCvAZ9jCMQCgK3pFqYgirwTgfwnPtxFxO/F3ZcS8jovza5khkSKL9JGq8Nk
 czDTruQ/oy0WUHdUr9uwEfiD9yPFOGqp4S6cISuzBMvaAiC5YGdUGXuPZKXLpnGSjkZswUzY
 d9BVSitRL5ldsQCg6GhDoEAeIhUC4SQnT9SOWkoDOSFRXZ+7+WIBGLiWMd+yKDdRG5RyP/8f
 3tgGiB6cyuYfPDRGsELGjUaTUq3H2xZgIPfOwE0EU4xwFgEIAMsx+gDjgzAY4H1hPVXgoLK8
 B93sTQFN9oC6tsb46VpxyLPfJ3T1A6Z6MVkLoCejKTJ3K9MUsBZhxIJ0hIyvzwI6aYJsnOew
 cCiCN7FeKJ/oA1RSUemPGUcIJwQuZlTOiY0OcQ5PFkV5YxMUX1F/aTYXROXgTmSaw0aC1Jpo
 w7Ss1mg4SIP/tR88/d1+HwkJDVW1RSxC1PWzGizwRv8eauImGdpNnseneO2BNWRXTJumAWDD
 pYxpGSsGHXuZXTPZqOOZpsHtInFyi5KRHSFyk2Xigzvh3b9WqhbgHHHE4PUVw0I5sIQt8hJq
 5nH5dPqz4ITtCL9zjiJsExHuHKN3NZsAEQEAAcLAXwQYAQIACQUCU4xwFgIbDAAKCRCw3p3W
 KL8TL0P4B/9YWver5uD/y/m0KScK2f3Z3mXJhME23vGBbMNlfwbr+meDMrJZ950CuWWnQ+d+
 Ahe0w1X7e3wuLVODzjcReQ/v7b4JD3wwHxe+88tgB9byc0NXzlPJWBaWV01yB2/uefVKryAf
 AHYEd0gCRhx7eESgNBe3+YqWAQawunMlycsqKa09dBDL1PFRosF708ic9346GLHRc6Vj5SRA
 UTHnQqLetIOXZm3a2eQ1gpQK9MmruO86Vo93p39bS1mqnLLspVrL4rhoyhsOyh0Hd28QCzpJ
 wKeHTd0MAWAirmewHXWPco8p1Wg+V+5xfZzuQY0f4tQxvOpXpt4gQ1817GQ5/Ed/wsDtBBgB
 CAAgFiEEhRJncuj2BJSl0Jf3sN6d1ii/Ey8FAlrd8NACGwIAgQkQsN6d1ii/Ey92IAQZFggA
 HRYhBFMtsHpB9jjzHji4HoBcYbtP2GO+BQJa3fDQAAoJEIBcYbtP2GO+TYsA/30H/0V6cr/W
 V+J/FCayg6uNtm3MJLo4rE+o4sdpjjsGAQCooqffpgA+luTT13YZNV62hAnCLKXH9n3+ZAgJ
 RtAyDWk1B/0SMDVs1wxufMkKC3Q/1D3BYIvBlrTVKdBYXPxngcRoqV2J77lscEvkLNUGsu/z
 W2pf7+P3mWWlrPMJdlbax00vevyBeqtqNKjHstHatgMZ2W0CFC4hJ3YEetuRBURYPiGzuJXU
 pAd7a7BdsqWC4o+GTm5tnGrCyD+4gfDSpkOT53S/GNO07YkPkm/8J4OBoFfgSaCnQ1izwgJQ
 jIpcG2fPCI2/hxf2oqXPYbKr1v4Z1wthmoyUgGN0LPTIm+B5vdY82wI5qe9uN6UOGyTH2B3p
 hRQUWqCwu2sqkI3LLbTdrnyDZaixT2T0f4tyF5Lfs+Ha8xVMhIyzNb1byDI5FKCb
Message-ID: <9a285a75-b9ea-37a9-b5bd-ba2a068dd944@suse.com>
Date:   Tue, 5 Mar 2019 15:57:44 +0100
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101
 Thunderbird/60.3.0
MIME-Version: 1.0
In-Reply-To: <35654e1a-d066-0581-749f-7e3b65023988@oracle.com>
Content-Type: text/plain; charset=utf-8
Content-Language: de-DE
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On 05/03/2019 14:43, Boris Ostrovsky wrote:
> On 3/5/19 8:30 AM, Arnd Bergmann wrote:
>>  
>> diff --git a/drivers/xen/privcmd.c b/drivers/xen/privcmd.c
>> index b24ddac1604b..290b6aca7e1d 100644
>> --- a/drivers/xen/privcmd.c
>> +++ b/drivers/xen/privcmd.c
>> @@ -723,26 +723,6 @@ static long privcmd_ioctl_restrict(struct file *file, void __user *udata)
>>  	return 0;
>>  }
>>  
>> -struct remap_pfn {
>> -	struct mm_struct *mm;
>> -	struct page **pages;
>> -	pgprot_t prot;
>> -	unsigned long i;
>> -};
>> -
>> -static int remap_pfn_fn(pte_t *ptep, pgtable_t token, unsigned long addr,
>> -			void *data)
>> -{
>> -	struct remap_pfn *r = data;
>> -	struct page *page = r->pages[r->i];
>> -	pte_t pte = pte_mkspecial(pfn_pte(page_to_pfn(page), r->prot));
>> -
>> -	set_pte_at(r->mm, addr, ptep, pte);
>> -	r->i++;
>> -
>> -	return 0;
>> -}
>> -
>>  static long privcmd_ioctl_mmap_resource(struct file *file, void __user *udata)
>>  {
>>  	struct privcmd_data *data = file->private_data;
>> @@ -809,15 +789,7 @@ static long privcmd_ioctl_mmap_resource(struct file *file, void __user *udata)
>>  		goto out;
>>  
>>  	if (xen_feature(XENFEAT_auto_translated_physmap)) {
>> -		struct remap_pfn r = {
>> -			.mm = vma->vm_mm,
>> -			.pages = vma->vm_private_data,
>> -			.prot = vma->vm_page_prot,
>> -		};
>> -
>> -		rc = apply_to_page_range(r.mm, kdata.addr,
>> -					 kdata.num << PAGE_SHIFT,
>> -					 remap_pfn_fn, &r);
>> +		rc = xen_remap_vma_range(vma, kdata.addr, kdata.num << PAGE_SHIFT);
> 
> I wonder whether drivers/xen/xlate_mmu.c might be a good place for these
> routines.

Hmm, probably. This would require a stub in the header to avoid
problems in case of CONFIG_XEN_AUTO_XLATE not defined, though
(the #ifdef is already there).

I think this is the cleanest solution.


Juergen