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: General protection fault in `switch_mm_irqs_off()`
To:     Thomas Lendacky <Thomas.Lendacky@amd.com>,
        Thomas Gleixner <tglx@linutronix.de>
Cc:     Jiri Kosina <jikos@kernel.org>, "x86@kernel.org" <x86@kernel.org>,
        LKML <linux-kernel@vger.kernel.org>,
        Tim Chen <tim.c.chen@linux.intel.com>,
        Borislav Petkov <bp@alien8.de>
References: <784ab00e-ed72-c1bc-bc0c-31264deb7726@molgen.mpg.de>
 <alpine.LRH.2.00.1901041737290.28043@gjva.wvxbf.pm>
 <cb7ba667-562b-1e4c-f16e-7c11804bc98a@molgen.mpg.de>
 <alpine.DEB.2.21.1901091410500.1755@nanos.tec.linutronix.de>
 <5c38f377-f088-5684-91a5-c2cc2d64dbbd@molgen.mpg.de>
 <ea49acb9-8165-80a3-e6fe-b29123ad5795@amd.com>
From:   Paul Menzel <pmenzel@molgen.mpg.de>
Message-ID: <206f4322-c15e-6f0b-733d-fd19cd9c24a7@molgen.mpg.de>
Date:   Wed, 9 Jan 2019 15:34:35 +0100
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101
 Thunderbird/52.9.1
MIME-Version: 1.0
In-Reply-To: <ea49acb9-8165-80a3-e6fe-b29123ad5795@amd.com>
Content-Type: multipart/signed; protocol="application/pkcs7-signature"; micalg=sha-256; boundary="------------ms070104080805080709030904"
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

This is a cryptographically signed message in MIME format.

--------------ms070104080805080709030904
Content-Type: text/plain; charset=utf-8
Content-Language: en-US
Content-Transfer-Encoding: quoted-printable

Dear Thomas,


On 01/09/19 15:29, Lendacky, Thomas wrote:
> On 1/9/19 7:35 AM, Paul Menzel wrote:

>> On 01/09/19 14:16, Thomas Gleixner wrote:
>>
>>> On Wed, 9 Jan 2019, Paul Menzel wrote:
>>>> I get the same with microcode updates applied.
>>>>
>>>>     $ dmesg | grep 'microcode: CPU0: patch_level'
>>>>     [    3.809210] microcode: CPU0: patch_level=3D0x0600063e
>>>>     $ sudo modprobe msr
>>>>     $ sudo ./wrmsr 0x49 0x1
>>>>     wrmsr: CPU 0 cannot set MSR 0x00000049 to 0x0000000000000001
>>>>
>>>>> Could you please post /proc/cpuinfo from such a boot as well?
>>>
>>> /proc/cpuinfo unfortunately does not contain the amd specific IBPB fl=
ag,
>>> but the dmesg of the original report says:
>>>
>>>   Spectre V2 : mitigation: Enabling conditional Indirect Branch Predi=
ction Barrier
>>>
>>> which means, that the CPUID bit is set.
>>>
>>> Can you please provide the output of:
>>>
>>>   cpuid -1 -l 0x80000008 -r
>>>
>>> On my AMD Opteron(TM) Processor 6276 with microcode 0x600063d loaded =
I get:
>>>
>>>    0x80000008 0x00: eax=3D0x00003030 ebx=3D0x00000000 ecx=3D0x0000500=
f edx=3D0x00000000
>>>
>>> EBX is 0, which means that X86_FEATURE_AMD_IBPB is not enabled. So th=
e
>>> kernel does not try to use the speculation control MSR (0x49).
>>
>> With CPUID 20180519, I get the output below with both microcode update=
 versions.
>>
>> 0x600063d:
>>
>>     $ sudo ./cpuid -1 -l 0x80000008 -r
>>     CPU:
>>        0x80000008 0x00: eax=3D0x00003030 ebx=3D0x00000000 ecx=3D0x0000=
500f edx=3D0x00000000
>>
>> 0x600063e:
>>
>>     $ sudo ./cpuid -1 -l 0x80000008 -r
>>     CPU:
>>        0x80000008 0x00: eax=3D0x00003030 ebx=3D0x00000000 ecx=3D0x0000=
500f edx=3D0x00000000
>=20
> Hmmm... so ebx is 0 for both versions, so I'm not sure how IBPB is bein=
g
> set. What's the CPUID output for 0x07 (cpuid -1 -l 0x07 -r)?

    $ sudo ./cpuid -1 -l 0x07 -r
    CPU:
       0x00000007 0x00: eax=3D0x00000000 ebx=3D0x00000000 ecx=3D0x0000000=
0 edx=3D0x00000000


Kind regards,

Paul


--------------ms070104080805080709030904
Content-Type: application/pkcs7-signature; name="smime.p7s"
Content-Transfer-Encoding: base64
Content-Disposition: attachment; filename="smime.p7s"
Content-Description: S/MIME Cryptographic Signature
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--------------ms070104080805080709030904--