pvclock: Add CPU barriers to get correct version value

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commit 749d088b8e upstream.

Protocol for the "version" fields is: hypervisor raises it (making it
uneven) before it starts updating the fields and raises it again (making
it even) when it is done.  Thus the guest can make sure the time values
it got are consistent by checking the version before and after reading
them.

Add CPU barries after getting version value just like what function
vread_pvclock does, because all of callees in this function is inline.

Fixes: 502dfeff23
Signed-off-by: Minfei Huang <mnghuan@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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Minfei Huang 2016-05-27 14:17:10 +08:00 • committed by Greg Kroah-Hartman

parent aab045e9a9

commit ca3455867e

2 changed files with 6 additions and 0 deletions

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2

arch/x86/include/asm/pvclock.h

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4

arch/x86/kernel/pvclock.c

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