[PATCH v4 07/20] nubus: add trace-events for empty slot accesses

[Mark Cave-Ayland]

Increase the max_access_size to 4 bytes for empty Nubus slot and super slot
accesses to allow tracing of the Nubus enumeration process by the guest OS.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
---
 hw/nubus/nubus-bus.c  | 10 +++++++---
 hw/nubus/trace-events |  7 +++++++
 hw/nubus/trace.h      |  1 +
 meson.build           |  1 +
 4 files changed, 16 insertions(+), 3 deletions(-)
 create mode 100644 hw/nubus/trace-events
 create mode 100644 hw/nubus/trace.h

diff --git a/hw/nubus/nubus-bus.c b/hw/nubus/nubus-bus.c
index 63e7d66b95..39182db065 100644
--- a/hw/nubus/nubus-bus.c
+++ b/hw/nubus/nubus-bus.c
@@ -11,6 +11,7 @@
 #include "qemu/osdep.h"
 #include "hw/nubus/nubus.h"
 #include "qapi/error.h"
+#include "trace.h"
 
 
 static NubusBus *nubus_find(void)
@@ -23,12 +24,13 @@ static void nubus_slot_write(void *opaque, hwaddr addr, 
uint64_t val,
                              unsigned int size)
 {
     /* read only */
+    trace_nubus_slot_write(addr, val, size);
 }
 
-
 static uint64_t nubus_slot_read(void *opaque, hwaddr addr,
                                 unsigned int size)
 {
+    trace_nubus_slot_read(addr, size);
     return 0;
 }
 
@@ -38,7 +40,7 @@ static const MemoryRegionOps nubus_slot_ops = {
     .endianness = DEVICE_BIG_ENDIAN,
     .valid = {
         .min_access_size = 1,
-        .max_access_size = 1,
+        .max_access_size = 4,
     },
 };
 
@@ -46,11 +48,13 @@ static void nubus_super_slot_write(void *opaque, hwaddr 
addr, uint64_t val,
                                    unsigned int size)
 {
     /* read only */
+    trace_nubus_super_slot_write(addr, val, size);
 }
 
 static uint64_t nubus_super_slot_read(void *opaque, hwaddr addr,
                                       unsigned int size)
 {
+    trace_nubus_super_slot_read(addr, size);
     return 0;
 }
 
@@ -60,7 +64,7 @@ static const MemoryRegionOps nubus_super_slot_ops = {
     .endianness = DEVICE_BIG_ENDIAN,
     .valid = {
         .min_access_size = 1,
-        .max_access_size = 1,
+        .max_access_size = 4,
     },
 };
 
diff --git a/hw/nubus/trace-events b/hw/nubus/trace-events
new file mode 100644
index 0000000000..e31833d694
--- /dev/null
+++ b/hw/nubus/trace-events
@@ -0,0 +1,7 @@
+# See docs/devel/tracing.txt for syntax documentation.
+
+# nubus-bus.c
+nubus_slot_read(uint64_t addr, int size) "reading unassigned addr 0x%"PRIx64 " 
size %d"
+nubus_slot_write(uint64_t addr, uint64_t val, int size) "writing unassigned 
addr 0x%"PRIx64 " value 0x%"PRIx64 " size %d"
+nubus_super_slot_read(uint64_t addr, int size) "reading unassigned addr 
0x%"PRIx64 " size %d"
+nubus_super_slot_write(uint64_t addr, uint64_t val, int size) "writing 
unassigned addr 0x%"PRIx64 " value 0x%"PRIx64 " size %d"
diff --git a/hw/nubus/trace.h b/hw/nubus/trace.h
new file mode 100644
index 0000000000..3749420da1
--- /dev/null
+++ b/hw/nubus/trace.h
@@ -0,0 +1 @@
+#include "trace/trace-hw_nubus.h"
diff --git a/meson.build b/meson.build
index 2711cbb789..612ce671b5 100644
--- a/meson.build
+++ b/meson.build
@@ -2135,6 +2135,7 @@ if have_system
     'hw/misc/macio',
     'hw/net',
     'hw/net/can',
+    'hw/nubus',
     'hw/nvme',
     'hw/nvram',
     'hw/pci',
-- 
2.20.1