trace: Add 'vcpu' event property to trace guest vCPU

This property identifies events that trace vCPU-specific information.

It adds a "CPUState*" argument to events with the property, identifying
the vCPU raising the event. TCG translation events also have a
"TCGv_env" implicit argument that is later used as the "CPUState*"
argument at execution time.

Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu>
Message-id: 145641861797.30295.6991314023181842105.stgit@localhost
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

docs/tracing.txt

@@ -344,3 +344,44 @@ This will immediately call:
 and will generate the TCG code to call:
 
     void trace_foo(uint8_t a1, uint32_t a2);
+
+=== "vcpu" ===
+
+Identifies events that trace vCPU-specific information. It implicitly adds a
+"CPUState*" argument, and extends the tracing print format to show the vCPU
+information. If used together with the "tcg" property, it adds a second
+"TCGv_env" argument that must point to the per-target global TCG register that
+points to the vCPU when guest code is executed (usually the "cpu_env" variable).
+
+The following example events:
+
+    foo(uint32_t a) "a=%x"
+    vcpu bar(uint32_t a) "a=%x"
+    tcg vcpu baz(uint32_t a) "a=%x", "a=%x"
+
+Can be used as:
+
+    #include "trace-tcg.h"
+    
+    CPUArchState *env;
+    TCGv_ptr cpu_env;
+    
+    void some_disassembly_func(...)
+    {
+        /* trace emitted at this point */
+        trace_foo(0xd1);
+        /* trace emitted at this point */
+        trace_bar(ENV_GET_CPU(env), 0xd2);
+        /* trace emitted at this point (env) and when guest code is executed (cpu_env) */
+        trace_baz_tcg(ENV_GET_CPU(env), cpu_env, 0xd3);
+    }
+
+If the translating vCPU has address 0xc1 and code is later executed by vCPU
+0xc2, this would be an example output:
+
+    // at guest code translation
+    foo a=0xd1
+    bar cpu=0xc1 a=0xd2
+    baz_trans cpu=0xc1 a=0xd3
+    // at guest code execution
+    baz_exec cpu=0xc2 a=0xd3

scripts/tracetool/__init__.py

@@ -161,7 +161,7 @@ class Event(object):
                       "(?:(?:(?P<fmt_trans>\".+),)?\s*(?P<fmt>\".+))?"
                       "\s*")
 
-    _VALID_PROPS = set(["disable", "tcg", "tcg-trans", "tcg-exec"])
+    _VALID_PROPS = set(["disable", "tcg", "tcg-trans", "tcg-exec", "vcpu"])
 
     def __init__(self, name, props, fmt, args, orig=None):
         """
@@ -230,7 +230,13 @@ class Event(object):
         if "tcg" in props and isinstance(fmt, str):
             raise ValueError("Events with 'tcg' property must have two formats")
 
-        return Event(name, props, fmt, args)
+        event = Event(name, props, fmt, args)
+
+        # add implicit arguments when using the 'vcpu' property
+        import tracetool.vcpu
+        event = tracetool.vcpu.transform_event(event)
+
+        return event
 
     def __repr__(self):
         """Evaluable string representation for this object."""
@@ -285,6 +291,7 @@ def _read_events(fobj):
             event_trans.name += "_trans"
             event_trans.properties += ["tcg-trans"]
             event_trans.fmt = event.fmt[0]
+            # ignore TCG arguments
             args_trans = []
             for atrans, aorig in zip(
                     event_trans.transform(tracetool.transform.TCG_2_HOST).args,

scripts/tracetool/format/h.py

@@ -6,7 +6,7 @@ trace/generated-tracers.h
 """
 
 __author__     = "Lluís Vilanova <vilanova@ac.upc.edu>"
-__copyright__  = "Copyright 2012-2014, Lluís Vilanova <vilanova@ac.upc.edu>"
+__copyright__  = "Copyright 2012-2016, Lluís Vilanova <vilanova@ac.upc.edu>"
 __license__    = "GPL version 2 or (at your option) any later version"
 
 __maintainer__ = "Stefan Hajnoczi"
@@ -23,6 +23,7 @@ def generate(events, backend):
         '#define TRACE__GENERATED_TRACERS_H',
         '',
         '#include "qemu-common.h"',
+        '#include "qemu/typedefs.h"',
         '')
 
     backend.generate_begin(events)

scripts/tracetool/format/tcg_h.py

@@ -13,7 +13,18 @@ __maintainer__ = "Stefan Hajnoczi"
 __email__      = "stefanha@linux.vnet.ibm.com"
 
 
-from tracetool import out
+from tracetool import out, Arguments
+import tracetool.vcpu
+
+
+def vcpu_transform_args(args):
+    assert len(args) == 1
+    return Arguments([
+        args,
+        # NOTE: this name must be kept in sync with the one in "tcg_h"
+        # NOTE: Current helper code uses TCGv_env (CPUArchState*)
+        ("TCGv_env", "__tcg_" + args.names()[0]),
+    ])
 
 
 def generate(events, backend):
@@ -35,21 +46,21 @@ def generate(events, backend):
         if "tcg-trans" not in e.properties:
             continue
 
-        # get the original event definition
-        e = e.original
-
         out('static inline void %(name_tcg)s(%(args)s)',
             '{',
-            name_tcg=e.api(e.QEMU_TRACE_TCG),
-            args=e.args)
+            name_tcg=e.original.api(e.QEMU_TRACE_TCG),
+            args=tracetool.vcpu.transform_args("tcg_h", e.original))
 
         if "disable" not in e.properties:
+            args_trans = e.original.event_trans.args
+            args_exec = tracetool.vcpu.transform_args(
+                "tcg_helper_c", e.original.event_exec, "wrapper")
             out('    %(name_trans)s(%(argnames_trans)s);',
                 '    gen_helper_%(name_exec)s(%(argnames_exec)s);',
-                name_trans=e.event_trans.api(e.QEMU_TRACE),
-                name_exec=e.event_exec.api(e.QEMU_TRACE),
-                argnames_trans=", ".join(e.event_trans.args.names()),
-                argnames_exec=", ".join(e.event_exec.args.names()))
+                name_trans=e.original.event_trans.api(e.QEMU_TRACE),
+                name_exec=e.original.event_exec.api(e.QEMU_TRACE),
+                argnames_trans=", ".join(args_trans.names()),
+                argnames_exec=", ".join(args_exec.names()))
 
         out('}')
 

scripts/tracetool/format/tcg_helper_c.py

@@ -6,15 +6,38 @@ Generate trace/generated-helpers.c.
 """
 
 __author__     = "Lluís Vilanova <vilanova@ac.upc.edu>"
-__copyright__  = "Copyright 2012-2014, Lluís Vilanova <vilanova@ac.upc.edu>"
+__copyright__  = "Copyright 2012-2016, Lluís Vilanova <vilanova@ac.upc.edu>"
 __license__    = "GPL version 2 or (at your option) any later version"
 
 __maintainer__ = "Stefan Hajnoczi"
 __email__      = "stefanha@linux.vnet.ibm.com"
 
 
-from tracetool import out
+from tracetool import Arguments, out
 from tracetool.transform import *
+import tracetool.vcpu
+
+
+def vcpu_transform_args(args, mode):
+    assert len(args) == 1
+    # NOTE: this name must be kept in sync with the one in "tcg_h"
+    args = Arguments([(args.types()[0], "__tcg_" + args.names()[0])])
+    if mode == "code":
+        return Arguments([
+            # Does cast from helper requirements to tracing types
+            ("CPUState *", "ENV_GET_CPU(%s)" % args.names()[0]),
+        ])
+    else:
+        args = Arguments([
+            # NOTE: Current helper code uses TCGv_env (CPUArchState*)
+            ("CPUArchState *", args.names()[0]),
+        ])
+        if mode == "header":
+            return args
+        elif mode == "wrapper":
+            return args.transform(HOST_2_TCG)
+        else:
+            assert False
 
 
 def generate(events, backend):
@@ -34,18 +57,18 @@ def generate(events, backend):
         if "tcg-exec" not in e.properties:
             continue
 
-        # tracetool.generate always transforms types to host
-        e_args = e.original.args
-
-        values = ["(%s)%s" % (t, n)
-                  for t, n in e.args.transform(TCG_2_TCG_HELPER_DEF)]
+        e_args_api = tracetool.vcpu.transform_args(
+            "tcg_helper_c", e.original, "header").transform(
+                HOST_2_TCG_COMPAT, TCG_2_TCG_HELPER_DEF)
+        e_args_call = tracetool.vcpu.transform_args(
+            "tcg_helper_c", e, "code")
 
-        out('void %(name_tcg)s(%(args)s)',
+        out('void %(name_tcg)s(%(args_api)s)',
             '{',
-            '    %(name)s(%(values)s);',
+            '    %(name)s(%(args_call)s);',
             '}',
             name_tcg="helper_%s_proxy" % e.api(),
             name=e.api(),
-            args=e_args.transform(HOST_2_TCG_COMPAT, TCG_2_TCG_HELPER_DEF),
-            values=", ".join(values),
+            args_api=e_args_api,
+            args_call=", ".join(e_args_call.casted()),
             )

scripts/tracetool/format/tcg_helper_h.py

@@ -6,7 +6,7 @@ Generate trace/generated-helpers.h.
 """
 
 __author__     = "Lluís Vilanova <vilanova@ac.upc.edu>"
-__copyright__  = "Copyright 2012-2014, Lluís Vilanova <vilanova@ac.upc.edu>"
+__copyright__  = "Copyright 2012-2016, Lluís Vilanova <vilanova@ac.upc.edu>"
 __license__    = "GPL version 2 or (at your option) any later version"
 
 __maintainer__ = "Stefan Hajnoczi"
@@ -15,6 +15,7 @@ __email__      = "stefanha@linux.vnet.ibm.com"
 
 from tracetool import out
 from tracetool.transform import *
+import tracetool.vcpu
 
 
 def generate(events, backend):
@@ -29,11 +30,9 @@ def generate(events, backend):
         if "tcg-exec" not in e.properties:
             continue
 
-        # tracetool.generate always transforms types to host
-        e_args = e.original.args
-
         # TCG helper proxy declaration
         fmt = "DEF_HELPER_FLAGS_%(argc)d(%(name)s, %(flags)svoid%(types)s)"
+        e_args = tracetool.vcpu.transform_args("tcg_helper_c", e.original, "header")
         args = e_args.transform(HOST_2_TCG_COMPAT, HOST_2_TCG,
                                 TCG_2_TCG_HELPER_DECL)
         types = ", ".join(args.types())

scripts/tracetool/format/tcg_helper_wrapper_h.py

@@ -6,7 +6,7 @@ Generate trace/generated-helpers-wrappers.h.
 """
 
 __author__     = "Lluís Vilanova <vilanova@ac.upc.edu>"
-__copyright__  = "Copyright 2012-2014, Lluís Vilanova <vilanova@ac.upc.edu>"
+__copyright__  = "Copyright 2012-2016, Lluís Vilanova <vilanova@ac.upc.edu>"
 __license__    = "GPL version 2 or (at your option) any later version"
 
 __maintainer__ = "Stefan Hajnoczi"
@@ -15,6 +15,7 @@ __email__      = "stefanha@linux.vnet.ibm.com"
 
 from tracetool import out
 from tracetool.transform import *
+import tracetool.vcpu
 
 
 def generate(events, backend):
@@ -33,7 +34,7 @@ def generate(events, backend):
             continue
 
         # tracetool.generate always transforms types to host
-        e_args = e.original.args
+        e_args = tracetool.vcpu.transform_args("tcg_helper_c", e.original, "wrapper")
 
         # mixed-type to TCG helper bridge
         args_tcg_compat = e_args.transform(HOST_2_TCG_COMPAT)

scripts/tracetool/format/ust_events_c.py

@@ -32,4 +32,5 @@ def generate(events, backend):
         ' */',
         '#pragma GCC diagnostic ignored "-Wredundant-decls"',
         '',
+        '#include "qemu/typedefs.h"',
         '#include "generated-ust-provider.h"')

scripts/tracetool/transform.py

@@ -6,7 +6,7 @@ Type-transformation rules.
 """
 
 __author__     = "Lluís Vilanova <vilanova@ac.upc.edu>"
-__copyright__  = "Copyright 2012-2014, Lluís Vilanova <vilanova@ac.upc.edu>"
+__copyright__  = "Copyright 2012-2016, Lluís Vilanova <vilanova@ac.upc.edu>"
 __license__    = "GPL version 2 or (at your option) any later version"
 
 __maintainer__ = "Stefan Hajnoczi"
@@ -98,6 +98,7 @@ HOST_2_TCG = {
     "uint32_t": "TCGv_i32",
     "uint64_t": "TCGv_i64",
     "void *"  : "TCGv_ptr",
+    "CPUArchState *": "TCGv_env",
     None: _host_2_tcg,
     }
 
@@ -130,6 +131,7 @@ TCG_2_TCG_HELPER_DECL = {
     "TCGv_ptr": "ptr",
     "TCGv_i32": "i32",
     "TCGv_i64": "i64",
+    "TCGv_env": "env",
     None: _tcg_2_tcg_helper_decl_error,
     }
 

scripts/tracetool/vcpu.py

@@ -0,0 +1,70 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+
+"""
+Generic management for the 'vcpu' property.
+
+"""
+
+__author__     = "Lluís Vilanova <vilanova@ac.upc.edu>"
+__copyright__  = "Copyright 2016, Lluís Vilanova <vilanova@ac.upc.edu>"
+__license__    = "GPL version 2 or (at your option) any later version"
+
+__maintainer__ = "Stefan Hajnoczi"
+__email__      = "stefanha@linux.vnet.ibm.com"
+
+
+from tracetool import Arguments, try_import
+
+
+def transform_event(event):
+    """Transform event to comply with the 'vcpu' property (if present)."""
+    if "vcpu" in event.properties:
+        # events with 'tcg-trans' and 'tcg-exec' are auto-generated from
+        # already-patched events
+        assert "tcg-trans" not in event.properties
+        assert "tcg-exec" not in event.properties
+
+        event.args = Arguments([("CPUState *", "__cpu"), event.args])
+        if "tcg" in event.properties:
+            fmt = "\"cpu=%p \""
+            event.fmt = [fmt + event.fmt[0],
+                         fmt + event.fmt[1]]
+        else:
+            fmt = "\"cpu=%p \""
+            event.fmt = fmt + event.fmt
+    return event
+
+
+def transform_args(format, event, *args, **kwargs):
+    """Transforms the arguments to suit the specified format.
+
+    The format module must implement function 'vcpu_args', which receives the
+    implicit arguments added by the 'vcpu' property, and must return suitable
+    arguments for the given format.
+
+    The function is only called for events with the 'vcpu' property.
+
+    Parameters
+    ==========
+    format : str
+        Format module name.
+    event : Event
+    args, kwargs
+        Passed to 'vcpu_transform_args'.
+
+    Returns
+    =======
+    Arguments
+        The transformed arguments, including the non-implicit ones.
+
+    """
+    if "vcpu" in event.properties:
+        ok, func = try_import("tracetool.format." + format,
+                              "vcpu_transform_args")
+        assert ok
+        assert func
+        return Arguments([func(event.args[:1], *args, **kwargs),
+                          event.args[1:]])
+    else:
+        return event.args

trace/control.h

@@ -1,7 +1,7 @@
 /*
  * Interface for configuring and controlling the state of tracing events.
  *
- * Copyright (C) 2011-2014 Lluís Vilanova <vilanova@ac.upc.edu>
+ * Copyright (C) 2011-2016 Lluís Vilanova <vilanova@ac.upc.edu>
  *
  * This work is licensed under the terms of the GNU GPL, version 2 or later.
  * See the COPYING file in the top-level directory.
@@ -11,6 +11,7 @@
 #define TRACE__CONTROL_H
 
 #include "qemu-common.h"
+#include "qemu/typedefs.h"
 #include "trace/generated-events.h"