Messages in this thread Patch in this message | | | Date | Wed, 16 Sep 2009 15:36:48 -0700 | From | Greg KH <> | Subject | [patch 35/45] KVM guest: fix bogus wallclock physical address calculation |
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2.6.31-stable review patch. If anyone has any objections, please let us know.
------------------ From: Glauber Costa <glommer@redhat.com>
commit a20316d2aa41a8f4fd171648bad8f044f6060826 upstream.
The use of __pa() to calculate the address of a C-visible symbol is wrong, and can lead to unpredictable results. See arch/x86/include/asm/page.h for details.
It should be replaced with __pa_symbol(), that does the correct math here, by taking relocations into account. This ensures the correct wallclock data structure physical address is passed to the hypervisor.
Signed-off-by: Glauber Costa <glommer@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
--- arch/x86/kernel/kvmclock.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
--- a/arch/x86/kernel/kvmclock.c +++ b/arch/x86/kernel/kvmclock.c @@ -50,8 +50,8 @@ static unsigned long kvm_get_wallclock(v struct timespec ts; int low, high; - low = (int)__pa(&wall_clock); - high = ((u64)__pa(&wall_clock) >> 32); + low = (int)__pa_symbol(&wall_clock); + high = ((u64)__pa_symbol(&wall_clock) >> 32); native_write_msr(MSR_KVM_WALL_CLOCK, low, high); vcpu_time = &get_cpu_var(hv_clock);
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