Build failure with kernel 6.12: error: implicit declaration of function 'rdtsc'

[ncopa]

make: Entering directory '/home/ncopa/aports/community/vmm_clock-lts/src/lts'
make[1]: Entering directory '/usr/src/linux-headers-6.12.0-0-lts'
  CC [M]  /home/ncopa/aports/community/vmm_clock-lts/src/lts/vmm_clock_main.o
  CC [M]  /home/ncopa/aports/community/vmm_clock-lts/src/lts/pvclock.o
/home/ncopa/aports/community/vmm_clock-lts/src/lts/pvclock.c: In function 'pvclock_clocksource_read':
/home/ncopa/aports/community/vmm_clock-lts/src/lts/pvclock.c:63:17: error: implicit declaration of function 'rdtsc' [-Wimplicit-function-declaration]
   63 |         delta = rdtsc() - tsc_timestamp;
      |                 ^~~~~
make[3]: *** [scripts/Makefile.build:229: /home/ncopa/aports/community/vmm_clock-lts/src/lts/pvclock.o] Error 1
make[3]: *** Waiting for unfinished jobs....
make[2]: *** [/usr/src/linux-headers-6.12.0-0-lts/Makefile:1936: /home/ncopa/aports/community/vmm_clock-lts/src/lts] Error 2
make[1]: *** [Makefile:224: __sub-make] Error 2
make[1]: Leaving directory '/usr/src/linux-headers-6.12.0-0-lts'
make: *** [Makefile:14: module] Error 2
make: Leaving directory '/home/ncopa/aports/community/vmm_clock-lts/src/lts'

[ncopa]

diff --git a/pvclock.c b/pvclock.c
index fa92464..e918b97 100644
--- a/pvclock.c
+++ b/pvclock.c
@@ -5,6 +5,7 @@
  */
 #include <linux/sched.h>
 #include <linux/sched/clock.h>
+#include <asm/msr.h>
 
 #include "pvclock.h"