On 8/3/20 1:48 PM, Alex Bennée wrote:
>
> Claudio Fontana <cfontana@suse.de> writes:
>
>> Motivation and higher level steps:
>>
>> https://lists.gnu.org/archive/html/qemu-devel/2020-05/msg04628.html
>>
>> The biggest open item for me is, does it makes sense to:
>>
>>
>> 1) make icount TCG-only (building the icount module only under
>> CONFIG_TCG), as this series suggests, and provide a separate virtual
>> counter for qtest,
>
> Well icount certainly never has any use except with TCG - the fields are
> all wasted in the KVM case.
>
>> or
>>
>>
>> 2) continue to keep icount functions and fields, including vmstate,
>> in all softmmu builds because of qtest current use of field
>> qemu_icount_bias to implement its virtual counter for
>> qtest_clock_warp?
>
> Is this just a case of maintaining compatibility for saved VM images? We
> could certainly keep the fields in VM state and stub out (or warn?) if a
> icount related field turned up when reloading a VM into a KVM only build
> or a build with !tcg_enabled().
>
> I would defer to the vmstate experts on the best way to do this? Is the
> field currently unconditional? Certainly the rr bits are only registered
> when RR is enabled.
Hi Alex and all,
do we have a compatibility issue to worry about?
Ie, I assumed looking at the "needed" functions in vmstate that
if a VM contains a subfield that is unneeded when loaded, it would just be ignored.
But maybe this was a too optimistic assumption?
Thank you,
Claudio
>
>> If I understand correctly Paolo might be for 2) (?)
>> would also welcome additional input from the community in any direction
>> (Alex, Peter, Philippe?)
>>
>> ----
>>
>> RFC v2 -> v3:
>>
>> * provided defaults for all methods.
>> Only create_vcpu_thread is now a mandatory field. (Paolo)
>>
>> * separated new CpusAccel patch from its first user, new patch nr. 2:
>> "cpus: prepare new CpusAccel cpu accelerator interface"
>>
>> * new CpusAccel methods: get_virtual_clock and get_elapsed_ticks.
>> (Paolo)
>>
>> In this series, get_virtual_clock has a separate implementation
>> between TCG/icount and qtest,
>> while get_elapsed_ticks only returns a virtual counter for icount.
>>
>> Looking for more comments in this area.
>>
>> ----
>>
>> RFC v1 -> v2:
>>
>> * split the cpus.c accelerator refactoring into 6 patches.
>>
>> * other minor changes to be able to proceed step by step.
>>
>> ----
>>
>> * Rebased on commit 255ae6e2158c743717bed76c9a2365ee4bcd326e,
>> "replay: notify the main loop when there are no instructions"
>>
>> [SPLIT into part1 and part2]
>>
>> ----
>>
>> v6 -> v7:
>>
>> * rebased changes on top of Pavel Dovgalyuk changes to dma-helpers.c
>> "icount: make dma reads deterministic"
>>
>> ----
>>
>> v5 -> v6:
>>
>> * rebased changes on top of Emilio G. Cota changes to cpus.c
>> "cpu: convert queued work to a QSIMPLEQ"
>>
>> * keep a pointer in cpus.c instead of a copy of CpusAccel
>> (Alex)
>>
>> ----
>>
>>
>> v4 -> v5: rebase on latest master
>>
>> * rebased changes on top of roman series to remove one of the extra states for hvf.
>> (Is the result now functional for HVF?)
>>
>> * rebased changes on top of icount changes and fixes to icount_configure and
>> the new shift vmstate. (Markus)
>>
>> v3 -> v4:
>>
>> * overall: added copyright headers to all files that were missing them
>> (used copyright and license of the module the stuff was extracted from).
>> For the new interface files, added SUSE LLC.
>>
>> * 1/4 (move softmmu only files from root):
>>
>> MAINTAINERS: moved softmmu/cpus.c to its final location (from patch 2)
>>
>> * 2/4 (cpu-throttle):
>>
>> MAINTAINERS (to patch 1),
>> copyright Fabrice Bellard and license from cpus.c
>>
>> * 3/4 (cpu-timers, icount):
>>
>> - MAINTAINERS: add cpu-timers.c and icount.c to Paolo
>>
>> - break very long lines (patchew)
>>
>> - add copyright SUSE LLC, GPLv2 to cpu-timers.h
>>
>> - add copyright Fabrice Bellard and license from cpus.c to timers-state.h
>> as it is lifted from cpus.c
>>
>> - vl.c: in configure_accelerators bail out if icount_enabled()
>> and !tcg_enabled() as qtest does not enable icount anymore.
>>
>> * 4/4 (accel stuff to accel):
>>
>> - add copyright SUSE LLC to files that mostly only consist of the
>> new interface. Add whatever copyright was in the accelerator code
>> if instead they mostly consist of accelerator code.
>>
>> - change a comment to mention the result of the AccelClass experiment
>>
>> - moved qtest accelerator into accel/qtest/ , make it like the others.
>>
>> - rename xxx-cpus-interface to xxx-cpus (remove "interface" from names)
>>
>> - rename accel_int to cpus_accel
>>
>> - rename CpusAccel functions from cpu_synchronize_* to synchronize_*
>>
>>
>> --------
>>
>> v2 -> v3:
>>
>> * turned into a 4 patch series, adding a first patch moving
>> softmmu code currently in top_srcdir to softmmu/
>>
>> * cpu-throttle: moved to softmmu/
>>
>> * cpu-timers, icount:
>>
>> - moved to softmmu/
>>
>> - fixed assumption of qtest_enabled() => icount_enabled()
>> causing the failure of check-qtest-arm goal, in test-arm-mptimer.c
>>
>> Fix is in hw/core/ptimer.c,
>>
>> where the artificial timeout rate limit should not be applied
>> under qtest_enabled(), in a similar way to how it is not applied
>> for icount_enabled().
>>
>> * CpuAccelInterface: no change.
>>
>>
>> --------
>>
>>
>> v1 -> v2:
>>
>> * 1/3 (cpu-throttle): provide a description in the commit message
>>
>> * 2/3 (cpu-timers, icount): in this v2 separate icount from cpu-timers,
>> as icount is actually TCG-specific. Only build it under CONFIG_TCG.
>>
>> To do this, qtest had to be detached from icount. To this end, a
>> trivial global counter for qtest has been introduced.
>>
>> * 3/3 (CpuAccelInterface): provided a description.
>>
>> This is point 8) in that plan. The idea is to extract the unrelated parts
>> in cpus, and register interfaces from each single accelerator to the main
>> cpus module (cpus.c).
>>
>> While doing this RFC, I noticed some assumptions about Windows being
>> either TCG or HAX (not considering WHPX) that might need to be revisited.
>> I added a comment there.
>>
>> The thing builds successfully based on Linux cross-compilations for
>> windows/hax, windows/whpx, and I got a good build on Darwin/hvf.
>>
>> Tests run successully for tcg and kvm configurations, but did not test on
>> windows or darwin.
>>
>> Welcome your feedback and help on this,
>>
>> Claudio
>>
>> Claudio Fontana (8):
>> cpu-timers, icount: new modules
>> cpus: prepare new CpusAccel cpu accelerator interface
>> cpus: extract out TCG-specific code to accel/tcg
>> cpus: extract out qtest-specific code to accel/qtest
>> cpus: extract out kvm-specific code to accel/kvm
>> cpus: extract out hax-specific code to target/i386/
>> cpus: extract out whpx-specific code to target/i386/
>> cpus: extract out hvf-specific code to target/i386/hvf/
>>
>> MAINTAINERS | 5 +-
>> accel/Makefile.objs | 2 +-
>> accel/kvm/Makefile.objs | 2 +
>> accel/kvm/kvm-all.c | 14 +-
>> accel/kvm/kvm-cpus.c | 88 +++
>> accel/kvm/kvm-cpus.h | 17 +
>> accel/qtest/Makefile.objs | 2 +
>> accel/qtest/qtest-cpus.c | 91 +++
>> accel/qtest/qtest-cpus.h | 17 +
>> accel/{ => qtest}/qtest.c | 13 +-
>> accel/stubs/kvm-stub.c | 3 +-
>> accel/tcg/Makefile.objs | 1 +
>> accel/tcg/cpu-exec.c | 43 +-
>> accel/tcg/tcg-all.c | 19 +-
>> accel/tcg/tcg-cpus.c | 541 +++++++++++++
>> accel/tcg/tcg-cpus.h | 17 +
>> accel/tcg/translate-all.c | 3 +-
>> dma-helpers.c | 4 +-
>> docs/replay.txt | 6 +-
>> exec.c | 4 -
>> hw/core/cpu.c | 1 +
>> hw/core/ptimer.c | 8 +-
>> hw/i386/x86.c | 3 +-
>> include/exec/cpu-all.h | 4 +
>> include/exec/exec-all.h | 4 +-
>> include/qemu/timer.h | 24 +-
>> include/sysemu/cpu-timers.h | 84 ++
>> include/sysemu/cpus.h | 48 +-
>> include/sysemu/hw_accel.h | 69 +-
>> include/sysemu/kvm.h | 2 +-
>> include/sysemu/qtest.h | 2 +
>> include/sysemu/replay.h | 4 +-
>> replay/replay.c | 6 +-
>> softmmu/Makefile.objs | 2 +
>> softmmu/cpu-timers.c | 279 +++++++
>> softmmu/cpus.c | 1661 +++-------------------------------------
>> softmmu/icount.c | 497 ++++++++++++
>> softmmu/qtest.c | 34 +-
>> softmmu/timers-state.h | 69 ++
>> softmmu/vl.c | 11 +-
>> stubs/Makefile.objs | 6 +-
>> stubs/clock-warp.c | 7 -
>> stubs/cpu-get-clock.c | 3 +-
>> stubs/cpu-get-icount.c | 21 -
>> stubs/cpu-synchronize-state.c | 15 +
>> stubs/cpus-get-virtual-clock.c | 8 +
>> stubs/icount.c | 52 ++
>> stubs/qemu-timer-notify-cb.c | 8 +
>> stubs/qtest.c | 5 +
>> target/alpha/translate.c | 3 +-
>> target/arm/helper.c | 7 +-
>> target/i386/Makefile.objs | 7 +-
>> target/i386/hax-all.c | 6 +-
>> target/i386/hax-cpus.c | 85 ++
>> target/i386/hax-cpus.h | 17 +
>> target/i386/hax-i386.h | 2 +
>> target/i386/hax-posix.c | 12 +
>> target/i386/hax-windows.c | 20 +
>> target/i386/hvf/Makefile.objs | 2 +-
>> target/i386/hvf/hvf-cpus.c | 131 ++++
>> target/i386/hvf/hvf-cpus.h | 17 +
>> target/i386/hvf/hvf.c | 3 +
>> target/i386/whpx-all.c | 3 +
>> target/i386/whpx-cpus.c | 96 +++
>> target/i386/whpx-cpus.h | 17 +
>> target/riscv/csr.c | 8 +-
>> tests/ptimer-test-stubs.c | 7 +-
>> tests/test-timed-average.c | 2 +-
>> util/main-loop.c | 12 +-
>> util/qemu-timer.c | 14 +-
>> 70 files changed, 2528 insertions(+), 1772 deletions(-)
>> create mode 100644 accel/kvm/kvm-cpus.c
>> create mode 100644 accel/kvm/kvm-cpus.h
>> create mode 100644 accel/qtest/Makefile.objs
>> create mode 100644 accel/qtest/qtest-cpus.c
>> create mode 100644 accel/qtest/qtest-cpus.h
>> rename accel/{ => qtest}/qtest.c (81%)
>> create mode 100644 accel/tcg/tcg-cpus.c
>> create mode 100644 accel/tcg/tcg-cpus.h
>> create mode 100644 include/sysemu/cpu-timers.h
>> create mode 100644 softmmu/cpu-timers.c
>> create mode 100644 softmmu/icount.c
>> create mode 100644 softmmu/timers-state.h
>> delete mode 100644 stubs/clock-warp.c
>> delete mode 100644 stubs/cpu-get-icount.c
>> create mode 100644 stubs/cpu-synchronize-state.c
>> create mode 100644 stubs/cpus-get-virtual-clock.c
>> create mode 100644 stubs/icount.c
>> create mode 100644 stubs/qemu-timer-notify-cb.c
>> create mode 100644 target/i386/hax-cpus.c
>> create mode 100644 target/i386/hax-cpus.h
>> create mode 100644 target/i386/hvf/hvf-cpus.c
>> create mode 100644 target/i386/hvf/hvf-cpus.h
>> create mode 100644 target/i386/whpx-cpus.c
>> create mode 100644 target/i386/whpx-cpus.h
>
>