Commit 3d211d9f authored by Lluís Vilanova's avatar Lluís Vilanova Committed by Stefan Hajnoczi
Browse files

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: default avatarLluís Vilanova <vilanova@ac.upc.edu>
Message-id: 145641861797.30295.6991314023181842105.stgit@localhost
Signed-off-by: default avatarStefan Hajnoczi <stefanha@redhat.com>
parent b23197f9

docs/tracing.txt

+41 −0
Original line number Diff line number Diff line
@@ -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

+9 −2
Original line number Diff line number Diff line
@@ -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

+2 −1
Original line number Diff line number Diff line
@@ -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

+21 −10
Original line number Diff line number Diff line
@@ -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

+34 −11
Original line number Diff line number Diff line
@@ -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()),

            )