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).
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
