[patch 14/30] KVM guest: fix bogus wallclock physical address calculation

[Greg KH]

2.6.30-stable review patch.  If anyone has any objections, please let us know.

------------------
From: Glauber Costa <glommer@xxxxxxxxxx>

(cherry picked from commit a20316d2aa41a8f4fd171648bad8f044f6060826)

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@xxxxxxxxxx>
Signed-off-by: Avi Kivity <avi@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>
---
 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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