[PATCH 04/13] hw/riscv/trace-encoder.c: align ntrace messages with ones

N-Trace format requires idle bytes to be filled with 0xff, instead of
zeroes, like E-Trace format

Signed-off-by: Konstantin Semichastnov <[email protected]>
---
 hw/riscv/trace-encoder.c | 24 +++++++++++++++++++-----
 1 file changed, 19 insertions(+), 5 deletions(-)

diff --git a/hw/riscv/trace-encoder.c b/hw/riscv/trace-encoder.c
index 10e52e207e..703454c9b7 100644
--- a/hw/riscv/trace-encoder.c
+++ b/hw/riscv/trace-encoder.c
@@ -398,21 +398,35 @@ static void trencoder_send_message_smem(TraceEncoder *trencoder,
     hwaddr dest = trencoder_read_ramsink_writep(trencoder);
     bool wrapped = false;
 
+    if (trencoder->ntrace) {
+        /*
+         * RISC-V N-Trace 3.1. MSEO Sequences:
+         * idle bytes in N-Trace format are filled with 0xff, instead of zeroes
+         */
+        memset(msg + msg_size, 0xff, 4 - msg_size % 4);
+    }
     msg_size = QEMU_ALIGN_UP(msg_size, 4);
 
     /* clear trRamWrap before writing to SMEM */
     dest = FIELD_DP64(dest, TR_RAM_WP_LOW, WRAP, 0);
 
     /*
-     * Fill with null bytes if we can't fit the packet in
+     * Fill with idle bytes if we can't fit the packet in
      * ramlimit, set wrap and write the packet in ramstart.
      */
     if (dest + msg_size > trencoder->ramsink_ramlimit) {
-        g_autofree uint8_t *null_packet = NULL;
-        uint8_t null_size = trencoder->ramsink_ramlimit - dest;
+        g_autofree uint8_t *idle_packet = NULL;
+        uint8_t idle_size = trencoder->ramsink_ramlimit - dest;
 
-        null_packet = g_malloc0(null_size);
-        cpu_physical_memory_write(dest, null_packet, null_size);
+        idle_packet = g_malloc0(idle_size);
+        if (trencoder->ntrace) {
+            /*
+             * RISC-V N-Trace 3.1. MSEO Sequences:
+             * idle bytes in N-Trace format are filled with 0xff, instead of zeroes
+             */
+            memset(idle_packet, 0xff, idle_size);
+        }
+        cpu_physical_memory_write(dest, idle_packet, idle_size);
 
         dest = trencoder->ramsink_ramstart;
         wrapped = true;

-- 
2.43.0