Claudio Fontana <cfont...@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. > 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 -- Alex Bennée
