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;
Received-SPF: None (esa4.hc3370-68.iphmx.com: no sender
  authenticity information available from domain of
  sergey.dyasli@citrix.com) identity=pra;
  client-ip=162.221.158.21; receiver=esa4.hc3370-68.iphmx.com;
  envelope-from="sergey.dyasli@citrix.com";
  x-sender="sergey.dyasli@citrix.com";
  x-conformance=sidf_compatible
Received-SPF: Pass (esa4.hc3370-68.iphmx.com: domain of
  sergey.dyasli@citrix.com designates 162.221.158.21 as
  permitted sender) identity=mailfrom;
  client-ip=162.221.158.21; receiver=esa4.hc3370-68.iphmx.com;
  envelope-from="sergey.dyasli@citrix.com";
  x-sender="sergey.dyasli@citrix.com";
  x-conformance=sidf_compatible; x-record-type="v=spf1";
  x-record-text="v=spf1 ip4:209.167.231.154 ip4:178.63.86.133
  ip4:195.66.111.40/30 ip4:85.115.9.32/28 ip4:199.102.83.4
  ip4:192.28.146.160 ip4:192.28.146.107 ip4:216.52.6.88
  ip4:216.52.6.188 ip4:162.221.158.21 ip4:162.221.156.83
  ip4:168.245.78.127 ~all"
Received-SPF: None (esa4.hc3370-68.iphmx.com: no sender
  authenticity information available from domain of
  postmaster@mail.citrix.com) identity=helo;
  client-ip=162.221.158.21; receiver=esa4.hc3370-68.iphmx.com;
  envelope-from="sergey.dyasli@citrix.com";
  x-sender="postmaster@mail.citrix.com";
  x-conformance=sidf_compatible
IronPort-SDR: CDfu/Z3EtczMTzpEfAZPSlKPw+H9ASx9SLknEvZtvXAO/orpurrTD7fm1oG1CbkTm3bPIKKqcE
 XaF9PXjKhkCPzXqCgi84uDCo+RemjNh/65gMfG8+ZZ32QMpk2RC0NKgTJq8q6iPECwlikBFfqV
 bNWSAvt0+CdPwyWK08v4vI4mmHD7OF7uJv1TROtgDcKH63Mx1udzWkdfW54vrsqOxfLeSxbvn+
 XUN/aD7Wd1oz8Blud63w7wAdtUBgarO5W3lgetyx+NK9hMzWiaFaFhoa303hiqKFVJdBXapkfq
 10Q=
Subject: Re: [PATCH v2 2/4] x86/xen: add basic KASAN support for PV kernel
To:     Boris Ostrovsky <boris.ostrovsky@oracle.com>,
        <xen-devel@lists.xen.org>, <kasan-dev@googlegroups.com>,
        <linux-mm@kvack.org>, <linux-kernel@vger.kernel.org>
CC:     Andrey Ryabinin <aryabinin@virtuozzo.com>,
        Alexander Potapenko <glider@google.com>,
        Dmitry Vyukov <dvyukov@google.com>,
        Juergen Gross <jgross@suse.com>,
        Stefano Stabellini <sstabellini@kernel.org>,
        George Dunlap <george.dunlap@citrix.com>,
        Ross Lagerwall <ross.lagerwall@citrix.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        "sergey.dyasli@citrix.com >> Sergey Dyasli" 
        <sergey.dyasli@citrix.com>
References: <20200117125834.14552-1-sergey.dyasli@citrix.com>
 <20200117125834.14552-3-sergey.dyasli@citrix.com>
 <28aba070-fa53-5677-c2d2-97d06514dda8@oracle.com>
From:   Sergey Dyasli <sergey.dyasli@citrix.com>
Autocrypt: addr=sergey.dyasli@citrix.com; keydata=
 xsFNBFtMVHEBEADc/hZcLexrB6vGTdGqEUsYZkFGQh6Z1OO7bCtM1go1RugSMeq9tkFHQSOc
 9c7W9NVQqLgn8eefikIHxgic6tGgKoIQKcPuSsnqGao2YabsTSSoeatvmO5HkR0xGaUd+M6j
 iqv3cD7/WL602NhphT4ucKXCz93w0TeoJ3gleLuILxmzg1gDhKtMdkZv6TngWpKgIMRfoyHQ
 jsVzPbTTjJl/a9Cw99vuhFuEJfzbLA80hCwhoPM+ZQGFDcG4c25GQGQFFatpbQUhNirWW5b1
 r2yVOziSJsvfTLnyzEizCvU+r/Ek2Kh0eAsRFr35m2X+X3CfxKrZcePxzAf273p4nc3YIK9h
 cwa4ZpDksun0E2l0pIxg/pPBXTNbH+OX1I+BfWDZWlPiPxgkiKdgYPS2qv53dJ+k9x6HkuCy
 i61IcjXRtVgL5nPGakyOFQ+07S4HIJlw98a6NrptWOFkxDt38x87mSM7aSWp1kjyGqQTGoKB
 VEx5BdRS5gFdYGCQFc8KVGEWPPGdeYx9Pj2wTaweKV0qZT69lmf/P5149Pc81SRhuc0hUX9K
 DnYBa1iSHaDjifMsNXKzj8Y8zVm+J6DZo/D10IUxMuExvbPa/8nsertWxoDSbWcF1cyvZp9X
 tUEukuPoTKO4Vzg7xVNj9pbK9GPxSYcafJUgDeKEIlkn3iVIPwARAQABzShTZXJnZXkgRHlh
 c2xpIDxzZXJnZXkuZHlhc2xpQGNpdHJpeC5jb20+wsGlBBMBCgA4FiEEkI7HMI5EbM2FLA1L
 Aa+w5JvbyusFAltMVHECGwMFCwkIBwIGFQoJCAsCBBYCAwECHgECF4AAIQkQAa+w5JvbyusW
 IQSQjscwjkRszYUsDUsBr7Dkm9vK65AkEACvL+hErqbQj5yTVNqvP1rVGsXvevViglSTkHD4
 9LGwEk4+ne8N4DPcqrDnyqYFd42UxTjVyoDEXEIIoy0RHWCmaspYEDX8fVmgFG3OFoeA9NAv
 JHssHU6B2mDAQ6M3VDmAwTw+TbXL/c1wblgGAP9kdurydZL8bevTTUh7edfnm5pwaT9HLXvl
 xLjz5qyt6tKEowM0xPVzCKaj3Mf/cuZFOlaWiHZ0biOPC0JeoHuz4UQTnBBUKk+n2nnn72k9
 37cNeaxARwn/bxcej9QlbrrdaNGVFzjCA/CIL0KjUepowpLN0+lmYjkPgeLNYfyMXumlSNag
 9qnCTh0QDsCXS/HUHPeBskAvwNpGBCkfiP/XqJ+V618ZQ1sclHa9aWNnlIR/a8xVx25t/14V
 R8EX/045HUpyPU8hI/yw+Fw/ugJ8W0dFzFeHU5K2tEW2W0m3ZWWWgpcBSCB17DDLIPjGX1Qc
 J8jiVJ7E4rfvA1JBg9BxVw5LVuXg2FB6bqnDYALfY2ydATk+ZzMUAMMilaE7/5a2RMV4TYcd
 8Cf77LdgO0pB3vF6z1QmNA2IbOICtJOXpmvHj+dKFUt5hFVbvqXbuAjlrwFktbAFVGxaeIYz
 nQ44lQu9JqDuSH5yOytdek24Dit8SgEHGvumyj17liCG6kNzxd+2xh3uaUCA5MIALy5mZ87B
 TQRbTFRxARAAwqL3u/cPDA+BhU9ghtAkC+gyC5smWUL1FwTQ9CwTqcQpKt85PoaHn8sc5ctt
 Aj2fNT/F2vqQx/BthVOdkhj9LCwuslqBIqbri3XUyMLVV/Tf+ydzHW2AjufCowwgBguxedD1
 f9Snkv+As7ZgMg/GtDqDiCWBFg9PneKvr+FPPd2WmrI8Kium4X5Zjs/a6OGUWVcIBoPpu088
 z/0tlKYjTFLhoIEsf6ll4KvRQZIyGxclg3RBEuN+wgMbKppdUf2DBXYeCyrrPx809CUFzcik
 O99drWti2CV1gF8bnbUvfCewxwqgVKtHl2kfsm2+/lgG4CTyvnvWqUyHICZUqISdz5GidaXn
 TcPlsAeo2YU2NXbjwnmxzJEP/4FxgsjYIUbbxdmsK+PGre7HmGmaDZ8K77L3yHr/K7AH8mFs
 WUM5KiW4SnKyIQvdHkZMpvE4XrrirlZ+JI5vE043GzzpS2CGo0NFQmDJLRbpN/KQY6dkNVgA
 L0aDxJtAO1rXKYDSrvpL80bYyskQ4ivUa06v9SM2/bHi9bnp3Nf/fK6ErWKWmDOHWrnTgRML
 oQpcxoVPxw2CwyWT1069Y/CWwgnbj34+LMwMUYhPEZMitABpQE74dEtIFh0c2scm3K2QGhOP
 KQK3szqmXuX6MViMZLDh/B7FXLQyqwMBnZygfzZFM9vpDskAEQEAAcLBjQQYAQoAIBYhBJCO
 xzCORGzNhSwNSwGvsOSb28rrBQJbTFRxAhsMACEJEAGvsOSb28rrFiEEkI7HMI5EbM2FLA1L
 Aa+w5Jvbyuvvbg//S3d1+XL568K5BTHXaYxSqCeMqYbV9rPhEHyk+rzKtwNXSbSO8x0xZutL
 gYV+nkW0KMPH5Bz3I1xiRKAkiX/JLcMfx2HAXJ1Cv2rpR6bxyCGBJmuwR68uMS/gKe6AWwTY
 q2kt1rtZPjGl9OwVoWGJKbu2pFBLWmLAnHlXOL6WDSE1Mz2Ah3jMHOaSyAgPu1XSNa600gMJ
 QrSxgbe7bW72gCjeHcrIjfv+uh5cZ5/J/edpWXRuE4Tz82nxudBIHE2vnQEoJrXOh2kAJiYs
 G+IllDqFKDPrnS0R3DenBNG0Ir8h9W6heETnhQUc9NDFCSr81Mp0fROdBfYZnQzgSZMjN2eY
 pkNEWshJER4ZYY+7hAmqI51HnsKuM46QINh00jJHRMykW3TBMlwnUFxZ0gplAecjCFC7g2zj
 g1qNxLnxMS4wCsyEVhCkPyYnS8zuoa4ZUH37CezD01Ph4O1saln5+M4blHCEAUpZIkTGpUoi
 SEwtoxu6EEUYfbcjWgzJCs023hbRykZlFALoRNCwVz/FnPuVu291jn9kjvCTEeE6g2dCtOrO
 ukuXzk1tIeeoggsU7AJ0bzP7QOEhEckaBbP4k6ic26LJGWNMinllePyEMXzsgmMHVN//8wDT
 NWaanhP/JZ1v5Mfn8s1chIqC0sJIw73RvvuBkOa+jx0OwW3RFoQ=
Message-ID: <3570a312-04e9-c7f8-e348-e1c2dbd040db@citrix.com>
Date:   Wed, 22 Jan 2020 11:13:54 +0000
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101
 Thunderbird/68.2.2
MIME-Version: 1.0
In-Reply-To: <28aba070-fa53-5677-c2d2-97d06514dda8@oracle.com>
Content-Type: text/plain; charset="utf-8"
Content-Language: en-US
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On 17/01/2020 14:56, Boris Ostrovsky wrote:
>
>
> On 1/17/20 7:58 AM, Sergey Dyasli wrote:
>> --- a/arch/x86/mm/kasan_init_64.c
>> +++ b/arch/x86/mm/kasan_init_64.c
>> @@ -13,6 +13,9 @@
>>   #include <linux/sched/task.h>
>>   #include <linux/vmalloc.h>
>>   +#include <xen/xen.h>
>> +#include <xen/xen-ops.h>
>> +
>>   #include <asm/e820/types.h>
>>   #include <asm/pgalloc.h>
>>   #include <asm/tlbflush.h>
>> @@ -332,6 +335,11 @@ void __init kasan_early_init(void)
>>       for (i = 0; pgtable_l5_enabled() && i < PTRS_PER_P4D; i++)
>>           kasan_early_shadow_p4d[i] = __p4d(p4d_val);
>>   +    if (xen_pv_domain()) {
>> +        pgd_t *pv_top_pgt = xen_pv_kasan_early_init();
>> +        kasan_map_early_shadow(pv_top_pgt);
>> +    }
>> +
>
>
> I'd suggest replacing this with xen_kasan_early_init() and doing everything, including PV check, there. This way non-Xen code won't need to be aware of Xen-specific details such as guest types.

This would require exporting kasan_map_early_shadow() via kasan.h.
I'm fine with either approach.

>>       kasan_map_early_shadow(early_top_pgt);
>>       kasan_map_early_shadow(init_top_pgt);
>>   }
>> @@ -369,6 +377,8 @@ void __init kasan_init(void)
>>                   __pgd(__pa(tmp_p4d_table) | _KERNPG_TABLE));
>>       }
>>   +    xen_pv_kasan_pin_pgd(early_top_pgt);
>> +
>
> And drop "_pv" here (and below) for the same reason.

This is a reasonable suggestion.

>>       load_cr3(early_top_pgt);
>>       __flush_tlb_all();
>>   @@ -433,6 +443,8 @@ void __init kasan_init(void)
>>       load_cr3(init_top_pgt);
>>       __flush_tlb_all();
>>   +    xen_pv_kasan_unpin_pgd(early_top_pgt);
>> +
>>

--
Thanks,
Sergey