Commit a20316d2 authored by Glauber Costa's avatar Glauber Costa Committed by Avi Kivity

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: default avatarGlauber Costa <glommer@redhat.com>
Signed-off-by: default avatarAvi Kivity <avi@redhat.com>
parent 5fff7d27
......@@ -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);
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment