x86/tsc: Remove incorrect assertion from cstate_restore_tsc()...

..fix and move to write_tsc().

Signed-off-by: Keir Fraser <keir@xen.org>

1 files changed, 6 insertions, 1 deletions

diff --git a/xen/arch/x86/smpboot.c b/xen/arch/x86/smpboot.c
index fddf85f2fe..deab8f7607 100644
--- a/xen/arch/x86/smpboot.c
+++ b/xen/arch/x86/smpboot.c
@@ -175,7 +175,12 @@ static void synchronize_tsc_slave(unsigned int slave)
         while ( atomic_read(&tsc_count) != ((i<<1)-1) )
             cpu_relax();
         rmb();
-        write_tsc(tsc_value);
+        /*
+         * If a CPU has been physically hotplugged, we may as well write
+         * to its TSC in spite of X86_FEATURE_TSC_RELIABLE. The platform does
+         * not sync up a new CPU's TSC for us.
+         */
+        __write_tsc(tsc_value);
         atomic_inc(&tsc_count);
     }
 }