Dear stable kernel team,
Please apply fix commit 24223657806a0ebd0ae5c9caaf7b021091889cf2 to
all stable kernels that have commit
4788e5b4b2338f85fa42a712a182d8afd65d7c58 applied but don't have
24223657806a0ebd0ae5c9caaf7b021091889cf2 yet: v3.14 AFAICS.
Thanks!
Ingo
* Thomas D. <[email protected]> wrote:
> Hi,
>
> I already sent this mail 2 weeks ago to the LKML but didn't get any
> response.
>
> Now I am trying to mail you directly, the author or comitter of the bad
> and good commit.
>
> Please, could you help me to get this backported into 3.14 stable?
>
> Thanks.
>
>
> -Thomas
>
>
>
> -------- Forwarded Message --------
> Subject: Backport request for 3.14 stable to use rdmsrl_safe() first
> when initializing RAPL PMU to allow KVM guests to boot on Intel hosts
> Date: Wed, 16 Jul 2014 22:28:42 +0200
> From: Thomas D. <[email protected]>
> To: [email protected] <[email protected]>
>
> Hi,
>
> I upgraded my KVM guest from linux-3.10.48 to linux-3.14.12 and
> rebooting into the new kernel failed with
>
> [ 0.930047] Call Trace:
> [ 0.930047] [<ffffffff81af1d36>] rapl_pmu_init+0xae/0x1b4
> [ 0.930047] [<ffffffff81af1c88>] ? uncore_cpu_setup+0x13/0x13
> [ 0.930047] [<ffffffff81000332>] do_one_initcall+0x112/0x160
> [ 0.930047] [<ffffffff810df618>] ? parse_args+0x1e8/0x320
> [ 0.930047] [<ffffffff81aea02c>] kernel_init_freeable+0x173/0x1fe
> [ 0.930047] [<ffffffff81ae9842>] ? do_early_param+0x88/0x88
> [ 0.930047] [<ffffffff815c4d20>] ? rest_init+0x80/0x80
> [ 0.930047] [<ffffffff815c4d2e>] kernel_init+0xe/0xf0
> [ 0.930047] [<ffffffff815da56c>] ret_from_fork+0x7c/0xb0
> [ 0.930047] [<ffffffff815c4d20>] ? rest_init+0x80/0x80
> [ 0.930047] Code: 8b 14 10 e8 b0 47 1b 00 48 85 c0 49 89 c6 0f 84
> 8f 00 00 00 31 c0 b9 06 06 00 00 66 41 89 06 49 8d 46 10 49 89 46 10 49
> 89 46 18 <0f> 32 48 c1 e8 08 66 b9 1f 00 49 c7 46 20 c0 c7 a1 81 83 e0 1f
> [ 0.930047] RIP [<ffffffff8101f4b3>] rapl_cpu_prepare+0x83/0x110
> [ 0.930047] RSP <ffff88007c777dc0>
> [ 0.953901] ---[ end trace 1a5a32cf5298005d ]---
> [ 0.954374] Kernel panic - not syncing: Fatal exception
> [ 0.954947] Kernel Offset: 0x0 from 0xffffffff81000000 (relocation
> range: 0xffffffff80000000-0xffffffff9fffffff)
>
> I started a kernel bisect and the bad commit causing the problem was
>
> commit 4788e5b4b2338f85fa42a712a182d8afd65d7c58
> Author: Stephane Eranian <[email protected]>
> Date: Tue Nov 12 17:58:50 2013 +0100
>
> perf/x86: Add Intel RAPL PMU support
>
> [...]
>
>
> In v3.15 this bug is already fixed with commit
>
>
> commit 24223657806a0ebd0ae5c9caaf7b021091889cf2
> Author: Venkatesh Srinivas <[email protected]>
> Date: Thu Mar 13 12:36:26 2014 -0700
>
> perf/x86/intel: Use rdmsrl_safe() when initializing RAPL PMU
>
> CPUs which should support the RAPL counters according to
> Family/Model/Stepping may still issue #GP when attempting to access
> the RAPL MSRs. This may happen when Linux is running under KVM and
> we are passing-through host F/M/S data, for example. Use rdmsrl_safe
> to first access the RAPL_POWER_UNIT MSR; if this fails, do not
> attempt to use this PMU.
>
>
>
> Could you please help me getting this fix into 3.14 stable kernel?
>
> I am not sure if applying 24223657 against 3.14 stable is enough. That's
> why I am posting this to linux-kernel@vger following the "Reporting bugs
> for the Linux kernel" guide (linux-kernel@vger is the mailing list for
> the perf subsystem according to the the MAINTAINERS file) instead of
> posting this to the stable@vger list.
> Please correct me if I am doing something wrong. This is my first time
> doing something like that.
>
> Thanks!
>
> Bugzilla: https://bugs.gentoo.org/show_bug.cgi?id=516908
>
>
> -Thomas
>
>
----- End forwarded message -----
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