Re: [Qemu-devel] [PATCH v7 0/4] trace: Show vCPU info in guest code events

["Alex Bennée" <alex.bennee@linaro.org>]

Lluís Vilanova <vilanova@ac.upc.edu> writes:

> Lluís Vilanova writes:
>
>> NOTE: This series should complete the framework for guest code tracing. From
>>       here on, other series can concurrently add actual events and improve the
>>       guest code tracing features and performance (e.g., control tracing
>>       independently on each vCPU).
>
>> This series introduces the "vcpu" property for tracing events. This property
>> identifies events that are tied to a particular virtual CPU (e.g., executing an
>> instruction).
>
>> Events with this property have an implicit vcpu argument, which is shown in the
>> trace. In the case of events executed at TCG translation time, two implicit
>> arguments are added:
>
>> * The vCPU performing the code translation (shown in the translation-time trace)
>> * The vCPU executing the translated code (shown in the execution-time trace)
>
>> Note that the "vcpu" and "tcg" properties are not merged into a single one,
>> since events can be defined that relate to a vCPU but are never raised from TCG
>> code (e.g., interrupts).
>
> Hi,
>
> I guess it's been a hectic time to integrate patches, but I haven't received a
> comment on the tracing part since v4. If possible, I'd like to send an actual
> guest code event (vmem accesses) before the soft-freeze (once this series is
> accepted).

I don't see a reason you couldn't post a v8 of this series including the
actual use. It would help to see it being used in the wild and the
maintainer doesn't have to accept the whole series straight away.

>
>
> Cheers,
>   Lluis
>
>
>> Changes in v7
>> =============
>
>> * Fix the modified event copying code.
>> * Minor fix in commit message for patch 3.
>
>
>> Changes in v6
>> =============
>
>> * Rebase on 84c0781.
>> * Replace the added 'TCGv_cpu' type for 'TCGv_env', since the users are really
>>   pointing to 'CPUArchState'.
>> * Add functions to simplify event argument management.
>> * Add minor event copy cleanup (remove long "event.original.original" chains).
>> * Make it easier to change arguments injected by the 'vcpu' property.
>
>
>> Changes in v5
>> =============
>
>> * Rebase on 357e81c.
>> * Split from the previous (larger and more complex) v4 series.

Ahh I see it used to be. Perhaps maybe point to a public tree with the
example use?

>
>
>> Changes in v4
>> =============
>
>> * Fix typo in commit message (Stefan Hajnoczi).
>> * Simplify per-vCPU tracing state initialization (Stefan Hajnoczi).
>> * Update copyright years.
>
>
>> Changes in v3
>> =============
>
>> * Update QAPI version (Eric Blake).
>> * Fix '#optional' annotation in QAPI (Eric Blake).
>
>
>> Changes in v2
>> =============
>
>> * Rebase on 5522a84.
>> * Improve patch descriptions.
>> * Refactor code generation into a separate patch.
>> * Fix forward declarations (Stefan Hajnoczi & Eduardo Habkost).
>> * Fix "since" tags in QAPI interface (Eric Blake).
>> * Unify QAPI/QMP interface with an optional 'vcpu' argument (Eric Blake).
>> * Fix QMP+GTK header workaround (Stefan Hajnoczi).
>
>
>> Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu>
>> Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
>> ---
>
>> Lluís Vilanova (4):
>>       trace: Extend API to manage event arguments
>>       trace: Remove unnecessary intermediate event copies
>>       tcg: Add type for vCPU pointers
>>       trace: Add 'vcpu' event property to trace guest vCPU
>
>
>>  docs/tracing.txt                                 |   41 +++++++++++++
>>  include/qemu/typedefs.h                          |    1
>>  scripts/tracetool/__init__.py                    |   31 ++++++++--
>>  scripts/tracetool/format/events_h.py             |    4 +
>>  scripts/tracetool/format/h.py                    |    3 +
>>  scripts/tracetool/format/tcg_h.py                |   33 +++++++----
>>  scripts/tracetool/format/tcg_helper_c.py         |   35 +++++++++--
>>  scripts/tracetool/format/tcg_helper_h.py         |    7 +-
>>  scripts/tracetool/format/tcg_helper_wrapper_h.py |    5 +-
>>  scripts/tracetool/format/ust_events_c.py         |    1
>>  scripts/tracetool/transform.py                   |    4 +
>>  scripts/tracetool/vcpu.py                        |   69 ++++++++++++++++++++++
>>  target-alpha/translate.c                         |    2 -
>>  target-arm/translate.c                           |    2 -
>>  target-arm/translate.h                           |    2 -
>>  target-cris/translate.c                          |    2 -
>>  target-i386/translate.c                          |    2 -
>>  target-lm32/translate.c                          |    2 -
>>  target-m68k/translate.c                          |    2 -
>>  target-microblaze/translate.c                    |    2 -
>>  target-mips/translate.c                          |    2 -
>>  target-moxie/translate.c                         |    2 -
>>  target-openrisc/translate.c                      |    2 -
>>  target-ppc/translate.c                           |    2 -
>>  target-s390x/translate.c                         |    2 -
>>  target-sh4/translate.c                           |    2 -
>>  target-sparc/translate.c                         |    5 +-
>>  target-tilegx/translate.c                        |    2 -
>>  target-tricore/translate.c                       |    2 -
>>  target-unicore32/translate.c                     |    2 -
>>  target-xtensa/translate.c                        |    2 -
>>  tcg/tcg.h                                        |    1
>>  trace/control.h                                  |    3 +
>>  33 files changed, 224 insertions(+), 55 deletions(-)
>>  create mode 100644 scripts/tracetool/vcpu.py
>
>
>> To: qemu-devel@nongnu.org
>> Cc: Stefan Hajnoczi <stefanha@redhat.com>
>> Cc: Eduardo Habkost <ehabkost@redhat.com>
>> Cc: Eric Blake <eblake@redhat.com>
>> Cc: Alex Bennée <alex.bennee@linaro.org>


--
Alex Bennée