From cc335935bf2b6084f411e244ca5323b57f864855 Mon Sep 17 00:00:00 2001 From: Glauber Costa Date: Fri, 18 Sep 2009 20:08:06 -0300 Subject: [PATCH] KVM guest: fix bogus wallclock physical address calculation (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 Signed-off-by: Avi Kivity Signed-off-by: Greg Kroah-Hartman --- arch/x86/kernel/kvmclock.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/kvmclock.c b/arch/x86/kernel/kvmclock.c index 223af43f152..e5efcdcca31 100644 --- a/arch/x86/kernel/kvmclock.c +++ b/arch/x86/kernel/kvmclock.c @@ -50,8 +50,8 @@ static unsigned long kvm_get_wallclock(void) 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); -- 2.11.4.GIT