From: Glauber Costa Date: Mon, 31 Aug 2009 07:04:31 +0000 (-0400) Subject: KVM guest: fix bogus wallclock physical address calculation X-Git-Tag: v2.6.32-rc1~693^2~11 X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=a20316d2aa41a8f4fd171648bad8f044f6060826;p=karo-tx-linux.git KVM guest: fix bogus wallclock physical address calculation 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. Cc: stable@kernel.org Signed-off-by: Glauber Costa Signed-off-by: Avi Kivity --- diff --git a/arch/x86/kernel/kvmclock.c b/arch/x86/kernel/kvmclock.c index 223af43f1526..e5efcdcca31b 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);