Allows to see how the guest interacts with the device.

Signed-off-by: Bernhard Beschow <shentey@gmail.com>
---
 hw/timer/i8254.c      | 6 ++++++
 hw/timer/trace-events | 4 ++++
 2 files changed, 10 insertions(+)

diff --git a/hw/timer/i8254.c b/hw/timer/i8254.c
index 4b25c487f7..7033ebf50d 100644
--- a/hw/timer/i8254.c
+++ b/hw/timer/i8254.c
@@ -29,6 +29,7 @@
 #include "hw/timer/i8254.h"
 #include "hw/timer/i8254_internal.h"
 #include "qom/object.h"
+#include "trace.h"
 
 //#define DEBUG_PIT
 
@@ -130,6 +131,8 @@ static void pit_ioport_write(void *opaque, hwaddr addr,
     int channel, access;
     PITChannelState *s;
 
+    trace_pit_ioport_write(addr, val);
+
     addr &= 3;
     if (addr == 3) {
         channel = val >> 6;
@@ -248,6 +251,9 @@ static uint64_t pit_ioport_read(void *opaque, hwaddr addr,
             break;
         }
     }
+
+    trace_pit_ioport_read(addr, ret);
+
     return ret;
 }
 
diff --git a/hw/timer/trace-events b/hw/timer/trace-events
index c5b6db49f5..2bb51f95ea 100644
--- a/hw/timer/trace-events
+++ b/hw/timer/trace-events
@@ -49,6 +49,10 @@ cmsdk_apb_dualtimer_read(uint64_t offset, uint64_t data, unsigned size) "CMSDK A
 cmsdk_apb_dualtimer_write(uint64_t offset, uint64_t data, unsigned size) "CMSDK APB dualtimer write: offset 0x%" PRIx64 " data 0x%" PRIx64 " size %u"
 cmsdk_apb_dualtimer_reset(void) "CMSDK APB dualtimer: reset"
 
+# i8254.c
+pit_ioport_read(uint8_t addr, uint32_t value) "[0x%" PRIx8 "] -> 0x%" PRIx32
+pit_ioport_write(uint8_t addr, uint32_t value) "[0x%" PRIx8 "] <- 0x%" PRIx32
+
 # imx_gpt.c
 imx_gpt_set_freq(uint32_t clksrc, uint32_t freq) "Setting clksrc %u to %u Hz"
 imx_gpt_read(const char *name, uint64_t value) "%s -> 0x%08" PRIx64
-- 
2.51.1.dirty