Re: [RFC v8 00/22] i386 cleanup

[Claudio Fontana]

Sorry, new script.

this is of course "v8" of the i386 cleanup:
                                                                                
                                                            
v7 -> v8: add missing CONFIG_TCGs, fix bugs                                     
                                                            
                                                                                
                                                            
* add the prerequisite patches for "3 tcg" at the beginning of the              
                                                            
  series for convenience (already reviewed, queued by RH).                      
                                                            
                                                                                
                                                            
* add CONFIG_TCG to TCGCpuOperations and tcg_ops variable use                   
                                                            
                                                                                
                                                            
* reduce the scope of the realizefn refactoring, do not                         
                                                            
  introduce a separate cpu_accel_realize, and instead use the                   
                                                            
  existing cpu_exec_realizefn, there is not enough benefit                      
                                                            
  to introduce a new function.                                                  
                                                            
                                                                                
                                                            
* fix bugs in user mode due to attempt to move the tcg_region_init()            
                                                            
  early, so it could be done just once in tcg_init() for both                   
                                                            
  softmmu and user mode. Unfortunately it needs to remain deferred              
                                                            
  for user mode, as it needs to be done after prologue init and                 
                                                            
  after the GUEST_BASE has been set.      


On 12/5/20 5:14 PM, Claudio Fontana wrote:
> *** BLURB HERE ***
> 
> Hi all, this is v7 of the i386 cleanup,
> with the most interesting patches at the end.
> 
> v6 -> v7: integrate TCGCpuOperations, refactored cpu_exec_realizefn
> 
> * integrate TCGCpuOperations (Eduardo)
> 
> Taken some refactoring from Eduardo for Tcg-only operations on
> CPUClass.
> 
> * refactored cpu_exec_realizefn
> 
> The other main change is a refactoring of cpu_exec_realizefn,
> directly linked to the effort of making many cpu_exec operations
> TCG-only (Eduardo series above):
> 
> cpu_exec_realizefn is actually a TCG-only thing, with the
> exception of a couple things that can be done in base cpu code.
> 
> This changes all targets realizefn, so I guess I have to Cc:
> the Multiverse? (Universe was already CCed for all accelerators).
> 
> 
> v5 -> v6: remove MODULE_INIT_ACCEL_CPU
> 
> 
> instead, use a call to accel_init_interfaces().
> 
> * The class lookups are now general and performed in accel/
> 
>   new AccelCPUClass for new archs are supported as new
>   ones appear in the class hierarchy, no need for stubs.
> 
> * Split the code a bit better
> 
> 
> v4 -> v5: centralized and simplified initializations
> 
> I put in Cc: Emilio G. Cota, specifically because in patch 8
> I (re)moved for user-mode the call to tcg_regions_init().
> 
> The call happens now inside the tcg AccelClass machine_init,
> (so earlier). This seems to work fine, but thought to get the
> author opinion on this.
> 
> Rebased on "tcg-cpus: split into 3 tcg variants" series
> (queued by Richard), to avoid some code churn:
> 
> 
> https://lists.gnu.org/archive/html/qemu-devel/2020-10/msg04356.html
> 
> 
> * Extended AccelClass to user-mode.
> 
> user-mode now does not call tcg_exec_init directly,
> instead it uses the tcg accel class, and its init_machine method.
> 
> Since user-mode does not define or use a machine state,
> the machine is just passed as NULL.
> 
> The immediate advantage is that now we can call current_accel()
> from both user mode and softmmu, so we can work out the correct
> class to use for accelerator initializations.
> 
> * QOMification of CpusAccelOps
> 
> simple QOMification of CpusAccelOps abstract class.
> 
> * Centralized all accel_cpu_init, so only one per cpu-arch,
>   plus one for all accels will remain.
> 
>   So we can expect accel_cpu_init() to be limited to:
>   
>   softmmu/cpus.c - initializes the chosen softmmu accel ops for the cpus 
> module.
>   target/ARCH/cpu.c - initializes the chosen arch-specific cpu accelerator.
>   
> These changes are meant to address concerns/issues (Paolo):
> 
> 1) the use of if (tcg_enabled()) and similar in the module_init call path
> 
> 2) the excessive number of accel_cpu_init() to hunt down in the codebase.
> 
> 
> * Fixed wrong use of host_cpu_class_init (Eduardo)
> 
> 
> v3 -> v4: QOMification of X86CPUAccelClass
> 
> 
> In this version I basically QOMified X86CPUAccel, taking the
> suggestions from Eduardo as the starting point,
> but stopping just short of making it an actual QOM interface,
> using a plain abstract class, and then subclasses for the
> actual objects.
> 
> Initialization is still using the existing qemu initialization
> framework (module_call_init), which is I still think is better
> than the alternatives proposed, in the current state.
> 
> Possibly some improvements could be developed in the future here.
> In this case, effort should be put in keeping things extendible,
> in order not to be blocked once accelerators also become modules.
> 
> Motivation and higher level steps:
> 
> https://lists.gnu.org/archive/html/qemu-devel/2020-05/msg04628.html
> 
> Looking forward to your comments on this proposal,
> 
> Ciao,
> 
> Claudio
> 
> 
> Claudio Fontana (18):
>   accel/tcg: split CpusAccel into three TCG variants
>   accel/tcg: split tcg_start_vcpu_thread
>   accel/tcg: rename tcg-cpus functions to match module name
>   i386: move kvm accel files into kvm/
>   i386: move whpx accel files into whpx/
>   i386: move hax accel files into hax/
>   i386: hvf: remove stale MAINTAINERS entry for old hvf stubs
>   i386: move TCG accel files into tcg/
>   i386: move cpu dump out of helper.c into cpu-dump.c
>   i386: move TCG cpu class initialization out of helper.c
>   accel/tcg: split TCG-only code from cpu_exec_realizefn
>   accel: extend AccelState and AccelClass to user-mode
>   accel: replace struct CpusAccel with AccelOpsClass
>   accel: introduce AccelCPUClass extending CPUClass
>   i386: split cpu accelerators from cpu.c, using AccelCPUClass
>   cpu: call AccelCPUClass::cpu_realizefn in cpu_exec_realizefn
>   hw/core/cpu: call qemu_init_vcpu in cpu_common_realizefn
>   cpu: introduce cpu_accel_instance_init
> 
> Eduardo Habkost (9):
>   tcg: cpu_exec_{enter,exit} helpers
>   tcg: make CPUClass.cpu_exec_* optional
>   tcg: Make CPUClass.debug_excp_handler optional
>   cpu: Remove unnecessary noop methods
>   cpu: Introduce TCGCpuOperations struct
>   cpu: Move synchronize_from_tb() to tcg_ops
>   cpu: Move cpu_exec_* to tcg_ops
>   cpu: Move tlb_fill to tcg_ops
>   cpu: Move debug_excp_handler to tcg_ops
> 
>  MAINTAINERS                           |  19 +-
>  accel/accel-common.c                  | 105 +++++
>  accel/{accel.c => accel-softmmu.c}    |  60 +--
>  accel/accel-softmmu.h                 |  15 +
>  accel/accel-user.c                    |  24 ++
>  accel/kvm/kvm-all.c                   |   2 -
>  accel/kvm/kvm-cpus.c                  |  26 +-
>  accel/kvm/kvm-cpus.h                  |   2 -
>  accel/meson.build                     |   4 +-
>  accel/qtest/qtest.c                   |  25 +-
>  accel/tcg/cpu-exec.c                  |  66 +++-
>  accel/tcg/cputlb.c                    |   6 +-
>  accel/tcg/meson.build                 |   9 +-
>  accel/tcg/tcg-all.c                   |  14 +-
>  accel/tcg/tcg-cpus-icount.c           | 138 +++++++
>  accel/tcg/tcg-cpus-icount.h           |  19 +
>  accel/tcg/tcg-cpus-mttcg.c            | 134 +++++++
>  accel/tcg/tcg-cpus-mttcg.h            |  19 +
>  accel/tcg/tcg-cpus-rr.c               | 298 ++++++++++++++
>  accel/tcg/tcg-cpus-rr.h               |  21 +
>  accel/tcg/tcg-cpus.c                  | 539 +++-----------------------
>  accel/tcg/tcg-cpus.h                  |   8 +-
>  accel/tcg/user-exec.c                 |   6 +-
>  accel/xen/xen-all.c                   |  24 +-
>  bsd-user/main.c                       |  11 +-
>  cpu.c                                 |  71 ++--
>  hw/core/cpu.c                         |  30 +-
>  hw/i386/fw_cfg.c                      |   2 +-
>  hw/i386/intel_iommu.c                 |   2 +-
>  hw/i386/kvm/apic.c                    |   2 +-
>  hw/i386/kvm/clock.c                   |   2 +-
>  hw/i386/microvm.c                     |   2 +-
>  hw/i386/pc.c                          |   2 +-
>  hw/i386/pc_piix.c                     |   1 +
>  hw/i386/x86.c                         |   2 +-
>  include/hw/boards.h                   |   2 +-
>  include/hw/core/accel-cpu.h           |  25 ++
>  include/hw/core/cpu.h                 |  61 +--
>  include/hw/core/tcg-cpu-ops.h         |  56 +++
>  include/{sysemu => qemu}/accel.h      |  16 +-
>  include/sysemu/accel-ops.h            |  45 +++
>  include/sysemu/cpus.h                 |  26 +-
>  include/sysemu/hvf.h                  |   2 +-
>  include/sysemu/kvm.h                  |   2 +-
>  include/sysemu/kvm_int.h              |   2 +-
>  linux-user/main.c                     |   7 +-
>  meson.build                           |   1 +
>  softmmu/cpus.c                        |  12 +-
>  softmmu/icount.c                      |   2 +-
>  softmmu/memory.c                      |   2 +-
>  softmmu/qtest.c                       |   2 +-
>  softmmu/vl.c                          |   8 +-
>  target/alpha/cpu.c                    |  12 +-
>  target/arm/cpu.c                      |  14 +-
>  target/arm/cpu64.c                    |   5 +-
>  target/arm/cpu_tcg.c                  |   5 +-
>  target/avr/cpu.c                      |  11 +-
>  target/cris/cpu.c                     |  18 +-
>  target/hppa/cpu.c                     |   9 +-
>  target/i386/cpu-dump.c                | 537 +++++++++++++++++++++++++
>  target/i386/cpu.c                     | 418 ++------------------
>  target/i386/cpu.h                     | 120 +-----
>  target/i386/{ => hax}/hax-all.c       |   5 +-
>  target/i386/{ => hax}/hax-cpus.c      |  29 +-
>  target/i386/{ => hax}/hax-cpus.h      |   2 -
>  target/i386/{ => hax}/hax-i386.h      |   6 +-
>  target/i386/{ => hax}/hax-interface.h |   0
>  target/i386/{ => hax}/hax-mem.c       |   0
>  target/i386/{ => hax}/hax-posix.c     |   0
>  target/i386/{ => hax}/hax-posix.h     |   0
>  target/i386/{ => hax}/hax-windows.c   |   0
>  target/i386/{ => hax}/hax-windows.h   |   0
>  target/i386/hax/meson.build           |   7 +
>  target/i386/helper-tcg.h              | 112 ++++++
>  target/i386/helper.c                  | 539 +-------------------------
>  target/i386/host-cpu.c                | 198 ++++++++++
>  target/i386/host-cpu.h                |  19 +
>  target/i386/hvf/cpu.c                 |  65 ++++
>  target/i386/hvf/hvf-cpus.c            |  27 +-
>  target/i386/hvf/hvf-cpus.h            |   2 -
>  target/i386/hvf/hvf-i386.h            |   2 +-
>  target/i386/hvf/hvf.c                 |   3 +-
>  target/i386/hvf/meson.build           |   1 +
>  target/i386/hvf/x86_task.c            |   2 +-
>  target/i386/kvm/cpu.c                 | 148 +++++++
>  target/i386/{ => kvm}/hyperv-proto.h  |   0
>  target/i386/{ => kvm}/hyperv-stub.c   |   0
>  target/i386/{ => kvm}/hyperv.c        |   0
>  target/i386/{ => kvm}/hyperv.h        |   0
>  target/i386/kvm/kvm-cpu.h             |  41 ++
>  target/i386/{ => kvm}/kvm-stub.c      |   0
>  target/i386/{ => kvm}/kvm.c           |   3 +-
>  target/i386/{ => kvm}/kvm_i386.h      |   0
>  target/i386/kvm/meson.build           |   8 +
>  target/i386/kvm/trace-events          |   7 +
>  target/i386/kvm/trace.h               |   1 +
>  target/i386/machine.c                 |   4 +-
>  target/i386/meson.build               |  39 +-
>  target/i386/{ => tcg}/bpt_helper.c    |   1 +
>  target/i386/{ => tcg}/cc_helper.c     |   1 +
>  target/i386/tcg/cpu.c                 | 173 +++++++++
>  target/i386/{ => tcg}/excp_helper.c   |   1 +
>  target/i386/{ => tcg}/fpu_helper.c    |  33 +-
>  target/i386/{ => tcg}/int_helper.c    |   1 +
>  target/i386/{ => tcg}/mem_helper.c    |   1 +
>  target/i386/tcg/meson.build           |  14 +
>  target/i386/{ => tcg}/misc_helper.c   |   1 +
>  target/i386/{ => tcg}/mpx_helper.c    |   1 +
>  target/i386/{ => tcg}/seg_helper.c    |   1 +
>  target/i386/{ => tcg}/smm_helper.c    |   2 +
>  target/i386/{ => tcg}/svm_helper.c    |   1 +
>  target/i386/{ => tcg}/tcg-stub.c      |   0
>  target/i386/{ => tcg}/translate.c     |   1 +
>  target/i386/trace-events              |   6 -
>  target/i386/whpx/meson.build          |   4 +
>  target/i386/{ => whpx}/whp-dispatch.h |   0
>  target/i386/{ => whpx}/whpx-all.c     |   4 +-
>  target/i386/{ => whpx}/whpx-cpus.c    |  29 +-
>  target/i386/{ => whpx}/whpx-cpus.h    |   2 -
>  target/lm32/cpu.c                     |  11 +-
>  target/m68k/cpu.c                     |   8 +-
>  target/microblaze/cpu.c               |  17 +-
>  target/mips/cpu.c                     |  10 +-
>  target/moxie/cpu.c                    |   8 +-
>  target/nios2/cpu.c                    |  10 +-
>  target/openrisc/cpu.c                 |  10 +-
>  target/ppc/translate_init.c.inc       |  19 +-
>  target/riscv/cpu.c                    |  16 +-
>  target/rx/cpu.c                       |  16 +-
>  target/s390x/cpu.c                    |  11 +-
>  target/sh4/cpu.c                      |  10 +-
>  target/sparc/cpu.c                    |  12 +-
>  target/tilegx/cpu.c                   |   8 +-
>  target/tricore/cpu.c                  |   8 +-
>  target/unicore32/cpu.c                |  12 +-
>  target/xtensa/cpu.c                   |  10 +-
>  136 files changed, 2909 insertions(+), 1964 deletions(-)
>  create mode 100644 accel/accel-common.c
>  rename accel/{accel.c => accel-softmmu.c} (64%)
>  create mode 100644 accel/accel-softmmu.h
>  create mode 100644 accel/accel-user.c
>  create mode 100644 accel/tcg/tcg-cpus-icount.c
>  create mode 100644 accel/tcg/tcg-cpus-icount.h
>  create mode 100644 accel/tcg/tcg-cpus-mttcg.c
>  create mode 100644 accel/tcg/tcg-cpus-mttcg.h
>  create mode 100644 accel/tcg/tcg-cpus-rr.c
>  create mode 100644 accel/tcg/tcg-cpus-rr.h
>  create mode 100644 include/hw/core/accel-cpu.h
>  create mode 100644 include/hw/core/tcg-cpu-ops.h
>  rename include/{sysemu => qemu}/accel.h (94%)
>  create mode 100644 include/sysemu/accel-ops.h
>  create mode 100644 target/i386/cpu-dump.c
>  rename target/i386/{ => hax}/hax-all.c (99%)
>  rename target/i386/{ => hax}/hax-cpus.c (71%)
>  rename target/i386/{ => hax}/hax-cpus.h (95%)
>  rename target/i386/{ => hax}/hax-i386.h (95%)
>  rename target/i386/{ => hax}/hax-interface.h (100%)
>  rename target/i386/{ => hax}/hax-mem.c (100%)
>  rename target/i386/{ => hax}/hax-posix.c (100%)
>  rename target/i386/{ => hax}/hax-posix.h (100%)
>  rename target/i386/{ => hax}/hax-windows.c (100%)
>  rename target/i386/{ => hax}/hax-windows.h (100%)
>  create mode 100644 target/i386/hax/meson.build
>  create mode 100644 target/i386/helper-tcg.h
>  create mode 100644 target/i386/host-cpu.c
>  create mode 100644 target/i386/host-cpu.h
>  create mode 100644 target/i386/hvf/cpu.c
>  create mode 100644 target/i386/kvm/cpu.c
>  rename target/i386/{ => kvm}/hyperv-proto.h (100%)
>  rename target/i386/{ => kvm}/hyperv-stub.c (100%)
>  rename target/i386/{ => kvm}/hyperv.c (100%)
>  rename target/i386/{ => kvm}/hyperv.h (100%)
>  create mode 100644 target/i386/kvm/kvm-cpu.h
>  rename target/i386/{ => kvm}/kvm-stub.c (100%)
>  rename target/i386/{ => kvm}/kvm.c (99%)
>  rename target/i386/{ => kvm}/kvm_i386.h (100%)
>  create mode 100644 target/i386/kvm/meson.build
>  create mode 100644 target/i386/kvm/trace-events
>  create mode 100644 target/i386/kvm/trace.h
>  rename target/i386/{ => tcg}/bpt_helper.c (99%)
>  rename target/i386/{ => tcg}/cc_helper.c (99%)
>  create mode 100644 target/i386/tcg/cpu.c
>  rename target/i386/{ => tcg}/excp_helper.c (99%)
>  rename target/i386/{ => tcg}/fpu_helper.c (99%)
>  rename target/i386/{ => tcg}/int_helper.c (99%)
>  rename target/i386/{ => tcg}/mem_helper.c (99%)
>  create mode 100644 target/i386/tcg/meson.build
>  rename target/i386/{ => tcg}/misc_helper.c (99%)
>  rename target/i386/{ => tcg}/mpx_helper.c (99%)
>  rename target/i386/{ => tcg}/seg_helper.c (99%)
>  rename target/i386/{ => tcg}/smm_helper.c (99%)
>  rename target/i386/{ => tcg}/svm_helper.c (99%)
>  rename target/i386/{ => tcg}/tcg-stub.c (100%)
>  rename target/i386/{ => tcg}/translate.c (99%)
>  create mode 100644 target/i386/whpx/meson.build
>  rename target/i386/{ => whpx}/whp-dispatch.h (100%)
>  rename target/i386/{ => whpx}/whpx-all.c (99%)
>  rename target/i386/{ => whpx}/whpx-cpus.c (73%)
>  rename target/i386/{ => whpx}/whpx-cpus.h (96%)
>