From: Glauber Costa Date: Fri, 18 Sep 2009 23:08:06 +0000 (-0300) Subject: KVM guest: fix bogus wallclock physical address calculation X-Git-Tag: v2.6.30.9~20 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=cc335935bf2b6084f411e244ca5323b57f864855;p=thirdparty%2Fkernel%2Fstable.git 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 --- diff --git a/arch/x86/kernel/kvmclock.c b/arch/x86/kernel/kvmclock.c index 223af43f15260..e5efcdcca31b6 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);