> Am 18.08.2015 um 17:25 schrieb Radim Krčmář <rkrcmar@xxxxxxxxxx>:
>
> 2015-08-18 16:54+0200, Peter Lieven:
>> After some experiments I was able to find out the bad commit that introduced the regression:
>>
>> commit f30ebc312ca9def25650b4e1d01cdb425c310dca
>> Author: Radim Krčmář <rkrcmar@xxxxxxxxxx>
>> Date: Thu Oct 30 15:06:47 2014 +0100
>>
>> It seems that this optimisation is not working reliabliy after live migration. I can't reproduce if
>> I take a 3.19 kernel and revert this single commit.
>
> Hello, this bug has gone unnoticed for a long time so it is fixed only
> since v4.1 (and v3.19.stable was dead at that point).
thanks for the pointer. i noticed the regression some time ago, but never found the time to debug. some distros rely on 3.19 e.g. Ubuntu LTS 14.04.2. I will try to ping the maintainer.
Peter
>
> commit b6ac069532218027f2991cba01d7a72a200688b0
> Author: Radim Krčmář <rkrcmar@xxxxxxxxxx>
> Date: Fri Jun 5 20:57:41 2015 +0200
>
> KVM: x86: fix lapic.timer_mode on restore
>
> lapic.timer_mode was not properly initialized after migration, which
> broke few useful things, like login, by making every sleep eternal.
>
> Fix this by calling apic_update_lvtt in kvm_apic_post_state_restore.
>
> There are other slowpaths that update lvtt, so this patch makes sure
> something similar doesn't happen again by calling apic_update_lvtt
> after every modification.
>
> Cc: stable@xxxxxxxxxxxxxxx
> Fixes: f30ebc312ca9 ("KVM: x86: optimize some accesses to LVTT and SPIV")
> Signed-off-by: Radim Krčmář <rkrcmar@xxxxxxxxxx>
> Signed-off-by: Marcelo Tosatti <mtosatti@xxxxxxxxxx>
--
To unsubscribe from this list: send the line "unsubscribe kvm" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
