[Qemu-devel] [PATCH 1/2] trace: include CPU index in trace_memory_region_ops_*()

[Hollis Blanchard]

Knowing which CPU performed an action is essential for understanding SMP guest
behavior.

However, cpu_physical_memory_rw() may be executed by a machine init function,
before any VCPUs are running, when there is no CPU running ('current_cpu' is
NULL). In this case, store -1 in the trace record as the CPU index. Trace
analysis tools may need to be aware of this special case.

Signed-off-by: Hollis Blanchard <address@hidden>
---
 memory.c     | 48 ++++++++++++++++++++++++++++++++++++------------
 trace-events |  8 ++++----
 2 files changed, 40 insertions(+), 16 deletions(-)

diff --git a/memory.c b/memory.c
index 2d87c21..6ae7bae 100644
--- a/memory.c
+++ b/memory.c
@@ -395,13 +395,17 @@ static MemTxResult 
memory_region_oldmmio_read_accessor(MemoryRegion *mr,
                                                        MemTxAttrs attrs)
 {
     uint64_t tmp;
+    int cpu_index = -1;
+
+    if (current_cpu)
+        cpu_index = current_cpu->cpu_index;
 
     tmp = mr->ops->old_mmio.read[ctz32(size)](mr->opaque, addr);
     if (mr->subpage) {
-        trace_memory_region_subpage_read(mr, addr, tmp, size);
+        trace_memory_region_subpage_read(cpu_index, mr, addr, tmp, size);
     } else if (TRACE_MEMORY_REGION_OPS_READ_ENABLED) {
         hwaddr abs_addr = memory_region_to_absolute_addr(mr, addr);
-        trace_memory_region_ops_read(mr, abs_addr, tmp, size);
+        trace_memory_region_ops_read(cpu_index, mr, abs_addr, tmp, size);
     }
     *value |= (tmp & mask) << shift;
     return MEMTX_OK;
@@ -416,13 +420,17 @@ static MemTxResult  
memory_region_read_accessor(MemoryRegion *mr,
                                                 MemTxAttrs attrs)
 {
     uint64_t tmp;
+    int cpu_index = -1;
+
+    if (current_cpu)
+        cpu_index = current_cpu->cpu_index;
 
     tmp = mr->ops->read(mr->opaque, addr, size);
     if (mr->subpage) {
-        trace_memory_region_subpage_read(mr, addr, tmp, size);
+        trace_memory_region_subpage_read(cpu_index, mr, addr, tmp, size);
     } else if (TRACE_MEMORY_REGION_OPS_READ_ENABLED) {
         hwaddr abs_addr = memory_region_to_absolute_addr(mr, addr);
-        trace_memory_region_ops_read(mr, abs_addr, tmp, size);
+        trace_memory_region_ops_read(cpu_index, mr, abs_addr, tmp, size);
     }
     *value |= (tmp & mask) << shift;
     return MEMTX_OK;
@@ -438,13 +446,17 @@ static MemTxResult 
memory_region_read_with_attrs_accessor(MemoryRegion *mr,
 {
     uint64_t tmp = 0;
     MemTxResult r;
+    int cpu_index = -1;
+
+    if (current_cpu)
+        cpu_index = current_cpu->cpu_index;
 
     r = mr->ops->read_with_attrs(mr->opaque, addr, &tmp, size, attrs);
     if (mr->subpage) {
-        trace_memory_region_subpage_read(mr, addr, tmp, size);
+        trace_memory_region_subpage_read(cpu_index, mr, addr, tmp, size);
     } else if (TRACE_MEMORY_REGION_OPS_READ_ENABLED) {
         hwaddr abs_addr = memory_region_to_absolute_addr(mr, addr);
-        trace_memory_region_ops_read(mr, abs_addr, tmp, size);
+        trace_memory_region_ops_read(cpu_index, mr, abs_addr, tmp, size);
     }
     *value |= (tmp & mask) << shift;
     return r;
@@ -459,13 +471,17 @@ static MemTxResult 
memory_region_oldmmio_write_accessor(MemoryRegion *mr,
                                                         MemTxAttrs attrs)
 {
     uint64_t tmp;
+    int cpu_index = -1;
+
+    if (current_cpu)
+        cpu_index = current_cpu->cpu_index;
 
     tmp = (*value >> shift) & mask;
     if (mr->subpage) {
-        trace_memory_region_subpage_write(mr, addr, tmp, size);
+        trace_memory_region_subpage_write(cpu_index, mr, addr, tmp, size);
     } else if (TRACE_MEMORY_REGION_OPS_WRITE_ENABLED) {
         hwaddr abs_addr = memory_region_to_absolute_addr(mr, addr);
-        trace_memory_region_ops_write(mr, abs_addr, tmp, size);
+        trace_memory_region_ops_write(cpu_index, mr, abs_addr, tmp, size);
     }
     mr->ops->old_mmio.write[ctz32(size)](mr->opaque, addr, tmp);
     return MEMTX_OK;
@@ -480,13 +496,17 @@ static MemTxResult 
memory_region_write_accessor(MemoryRegion *mr,
                                                 MemTxAttrs attrs)
 {
     uint64_t tmp;
+    int cpu_index = -1;
+
+    if (current_cpu)
+        cpu_index = current_cpu->cpu_index;
 
     tmp = (*value >> shift) & mask;
     if (mr->subpage) {
-        trace_memory_region_subpage_write(mr, addr, tmp, size);
+        trace_memory_region_subpage_write(cpu_index, mr, addr, tmp, size);
     } else if (TRACE_MEMORY_REGION_OPS_WRITE_ENABLED) {
         hwaddr abs_addr = memory_region_to_absolute_addr(mr, addr);
-        trace_memory_region_ops_write(mr, abs_addr, tmp, size);
+        trace_memory_region_ops_write(cpu_index, mr, abs_addr, tmp, size);
     }
     mr->ops->write(mr->opaque, addr, tmp, size);
     return MEMTX_OK;
@@ -501,13 +521,17 @@ static MemTxResult 
memory_region_write_with_attrs_accessor(MemoryRegion *mr,
                                                            MemTxAttrs attrs)
 {
     uint64_t tmp;
+    int cpu_index = -1;
+
+    if (current_cpu)
+        cpu_index = current_cpu->cpu_index;
 
     tmp = (*value >> shift) & mask;
     if (mr->subpage) {
-        trace_memory_region_subpage_write(mr, addr, tmp, size);
+        trace_memory_region_subpage_write(cpu_index, mr, addr, tmp, size);
     } else if (TRACE_MEMORY_REGION_OPS_WRITE_ENABLED) {
         hwaddr abs_addr = memory_region_to_absolute_addr(mr, addr);
-        trace_memory_region_ops_write(mr, abs_addr, tmp, size);
+        trace_memory_region_ops_write(cpu_index, mr, abs_addr, tmp, size);
     }
     return mr->ops->write_with_attrs(mr->opaque, addr, tmp, size, attrs);
 }
diff --git a/trace-events b/trace-events
index a80dc1c..756ce86 100644
--- a/trace-events
+++ b/trace-events
@@ -1626,10 +1626,10 @@ disable exec_tb_exit(void *next_tb, unsigned int flags) 
"tb:%p flags=%x"
 translate_block(void *tb, uintptr_t pc, uint8_t *tb_code) "tb:%p, 
pc:0x%"PRIxPTR", tb_code:%p"
 
 # memory.c
-memory_region_ops_read(void *mr, uint64_t addr, uint64_t value, unsigned size) 
"mr %p addr %#"PRIx64" value %#"PRIx64" size %u"
-memory_region_ops_write(void *mr, uint64_t addr, uint64_t value, unsigned 
size) "mr %p addr %#"PRIx64" value %#"PRIx64" size %u"
-memory_region_subpage_read(void *mr, uint64_t offset, uint64_t value, unsigned 
size) "mr %p offset %#"PRIx64" value %#"PRIx64" size %u"
-memory_region_subpage_write(void *mr, uint64_t offset, uint64_t value, 
unsigned size) "mr %p offset %#"PRIx64" value %#"PRIx64" size %u"
+memory_region_ops_read(int cpu_index, void *mr, uint64_t addr, uint64_t value, 
unsigned size) "cpu %d mr %p addr %#"PRIx64" value %#"PRIx64" size %u"
+memory_region_ops_write(int cpu_index, void *mr, uint64_t addr, uint64_t 
value, unsigned size) "cpu %d mr %p addr %#"PRIx64" value %#"PRIx64" size %u"
+memory_region_subpage_read(int cpu_index, void *mr, uint64_t offset, uint64_t 
value, unsigned size) "cpu %d mr %p offset %#"PRIx64" value %#"PRIx64" size %u"
+memory_region_subpage_write(int cpu_index, void *mr, uint64_t offset, uint64_t 
value, unsigned size) "cpu %d mr %p offset %#"PRIx64" value %#"PRIx64" size %u"
 
 # qom/object.c
 object_dynamic_cast_assert(const char *type, const char *target, const char 
*file, int line, const char *func) "%s->%s (%s:%d:%s)"
-- 
1.9.1