On Fri, Dec 04, 2020 at 07:07:09PM +0100, Claudio Fontana wrote: > On 12/4/20 7:04 PM, Claudio Fontana wrote: > > On 12/4/20 6:28 PM, Eduardo Habkost wrote: > >> On Fri, Dec 04, 2020 at 06:10:49PM +0100, Philippe Mathieu-Daudé wrote: > >>> On 11/30/20 3:35 AM, Claudio Fontana wrote: > >>>> From: Eduardo Habkost <ehabk...@redhat.com> > >>>> > >>>> The TCG-specific CPU methods will be moved to a separate struct, > >>>> to make it easier to move accel-specific code outside generic CPU > >>>> code in the future. Start by moving tcg_initialize(). > >>> > >>> Good idea! One minor comment below. > >>> > >>>> > >>>> The new CPUClass.tcg_opts field may eventually become a pointer, > >>>> but keep it an embedded struct for now, to make code conversion > >>>> easier. > >>>> > >>>> Signed-off-by: Eduardo Habkost <ehabk...@redhat.com> > >>>> --- > >>>> MAINTAINERS | 1 + > >>>> cpu.c | 2 +- > >>>> include/hw/core/cpu.h | 9 ++++++++- > >>>> include/hw/core/tcg-cpu-ops.h | 25 +++++++++++++++++++++++++ > >>>> target/alpha/cpu.c | 2 +- > >>>> target/arm/cpu.c | 2 +- > >>>> target/avr/cpu.c | 2 +- > >>>> target/cris/cpu.c | 12 ++++++------ > >>>> target/hppa/cpu.c | 2 +- > >>>> target/i386/tcg-cpu.c | 2 +- > >>>> target/lm32/cpu.c | 2 +- > >>>> target/m68k/cpu.c | 2 +- > >>>> target/microblaze/cpu.c | 2 +- > >>>> target/mips/cpu.c | 2 +- > >>>> target/moxie/cpu.c | 2 +- > >>>> target/nios2/cpu.c | 2 +- > >>>> target/openrisc/cpu.c | 2 +- > >>>> target/ppc/translate_init.c.inc | 2 +- > >>>> target/riscv/cpu.c | 2 +- > >>>> target/rx/cpu.c | 2 +- > >>>> target/s390x/cpu.c | 2 +- > >>>> target/sh4/cpu.c | 2 +- > >>>> target/sparc/cpu.c | 2 +- > >>>> target/tilegx/cpu.c | 2 +- > >>>> target/tricore/cpu.c | 2 +- > >>>> target/unicore32/cpu.c | 2 +- > >>>> target/xtensa/cpu.c | 2 +- > >>>> 27 files changed, 63 insertions(+), 30 deletions(-) > >>>> create mode 100644 include/hw/core/tcg-cpu-ops.h > >>>> > >>>> diff --git a/MAINTAINERS b/MAINTAINERS > >>>> index f53f2678d8..d876f504a6 100644 > >>>> --- a/MAINTAINERS > >>>> +++ b/MAINTAINERS > >>>> @@ -1535,6 +1535,7 @@ F: qapi/machine.json > >>>> F: qapi/machine-target.json > >>>> F: include/hw/boards.h > >>>> F: include/hw/core/cpu.h > >>>> +F: include/hw/core/tcg-cpu-ops.h > >>>> F: include/hw/cpu/cluster.h > >>>> F: include/sysemu/numa.h > >>>> T: git https://github.com/ehabkost/qemu.git machine-next > >>>> diff --git a/cpu.c b/cpu.c > >>>> index 0be5dcb6f3..d02c2a17f1 100644 > >>>> --- a/cpu.c > >>>> +++ b/cpu.c > >>>> @@ -180,7 +180,7 @@ void cpu_exec_realizefn(CPUState *cpu, Error **errp) > >>>> > >>>> if (tcg_enabled() && !tcg_target_initialized) { > >>>> tcg_target_initialized = true; > >>>> - cc->tcg_initialize(); > >>>> + cc->tcg_ops.initialize(); > >>>> } > >>>> tlb_init(cpu); > >>>> > >>>> diff --git a/include/hw/core/cpu.h b/include/hw/core/cpu.h > >>>> index 3d92c967ff..c93b08a0fb 100644 > >>>> --- a/include/hw/core/cpu.h > >>>> +++ b/include/hw/core/cpu.h > >>>> @@ -76,6 +76,10 @@ typedef struct CPUWatchpoint CPUWatchpoint; > >>>> > >>>> struct TranslationBlock; > >>>> > >>>> +#ifdef CONFIG_TCG > >>>> +#include "tcg-cpu-ops.h" > >>>> +#endif /* CONFIG_TCG */ > >>>> + > >>>> /** > >>>> * CPUClass: > >>>> * @class_by_name: Callback to map -cpu command line model name to an > >>>> @@ -221,12 +225,15 @@ struct CPUClass { > >>>> > >>>> void (*disas_set_info)(CPUState *cpu, disassemble_info *info); > >>>> vaddr (*adjust_watchpoint_address)(CPUState *cpu, vaddr addr, int > >>>> len); > >>>> - void (*tcg_initialize)(void); > >>>> > >>>> const char *deprecation_note; > >>>> /* Keep non-pointer data at the end to minimize holes. */ > >>>> int gdb_num_core_regs; > >>>> bool gdb_stop_before_watchpoint; > >>>> + > >>>> +#ifdef CONFIG_TCG > >>>> + TcgCpuOperations tcg_ops; > >>>> +#endif /* CONFIG_TCG */ > >>>> }; > >> > >> I'm not a fan of #ifdefs in struct definitions (especially in > >> generic code like hw/cpu), because there's risk the same header > >> generate different struct layout when used by different .c files. > >> I would prefer to gradually refactor the code so that tcg_ops is > >> eventually removed from CPUClass. > >> > >> This is not a dealbreaker, because both approaches are steps in > >> the same direction. But the #ifdef here makes review harder and > >> has more risks of unwanted side effects. > >> > >>>> > >>>> /* > >>>> diff --git a/include/hw/core/tcg-cpu-ops.h > >>>> b/include/hw/core/tcg-cpu-ops.h > >>>> new file mode 100644 > >>>> index 0000000000..4475ef0996 > >>>> --- /dev/null > >>>> +++ b/include/hw/core/tcg-cpu-ops.h > >>>> @@ -0,0 +1,25 @@ > >>>> +/* > >>>> + * TCG-Specific operations that are not meaningful for hardware > >>>> accelerators > >>>> + * > >>>> + * Copyright 2020 SUSE LLC > >>>> + * > >>>> + * This work is licensed under the terms of the GNU GPL, version 2 or > >>>> later. > >>>> + * See the COPYING file in the top-level directory. > >>>> + */ > >>>> + > >>>> +#ifndef TCG_CPU_OPS_H > >>>> +#define TCG_CPU_OPS_H > >>>> + > >>>> +/** > >>>> + * struct TcgCpuOperations: TCG operations specific to a CPU class > >>>> + */ > >>>> +typedef struct TcgCpuOperations { > >>>> + /** > >>>> + * @initialize: Initalize TCG state > >>>> + * > >>>> + * Called when the first CPU is realized. > >>>> + */ > >>>> + void (*initialize)(void); > >>>> +} TcgCpuOperations; > >>>> + > >>>> +#endif /* TCG_CPU_OPS_H */ > >>> ... > >>> > >>>> diff --git a/target/arm/cpu.c b/target/arm/cpu.c > >>>> index 07492e9f9a..1fa9382a7c 100644 > >>>> --- a/target/arm/cpu.c > >>>> +++ b/target/arm/cpu.c > >>>> @@ -2261,7 +2261,7 @@ static void arm_cpu_class_init(ObjectClass *oc, > >>>> void *data) > >>>> cc->gdb_stop_before_watchpoint = true; > >>>> cc->disas_set_info = arm_disas_set_info; > >>>> #ifdef CONFIG_TCG > >>>> - cc->tcg_initialize = arm_translate_init; > >>>> + cc->tcg_ops.initialize = arm_translate_init; > >>> > >>> This one is correctly guarded by '#ifdef CONFIG_TCG'. > >>> > >>> For the other targets, can you either place it within > >>> the '#ifdef CONFIG_TCG' block or if there is none, add > >>> one please? > >> > >> As a new #ifdef risks having additional unwanted side effects, I > >> would prefer to do it in separate patch, just in case. > >> > >> This also applies to the #ifdef Claudio added to hw/core/cpu.h > >> above. In case we really want to do it, I would do it in a > >> separate patch. > > > > Hi Eduardo, > > > > yes, once things are settling we should dispose of as many #ifdefs are > > possible > > > By that I mean, as targets are adapted (arm, s390, ...) things can be > refactored in a similar was as for x86, > so that the ifdefs disappear, and meson instead controls which pieces are > built. > > When it comes to the extra field, it was already very useful to have it > #ifdef ed, > because it identified quite a few problem with the existing patches, ie, code > that was trying to use the field even though it was not there. > > So this step helps with finding all the right pieces to refactor away, > and then once things are in their proper place, we can take away the ifdef I > think.
That's a good point. Grepping for CONFIG_TCG will help us find out cases where the code still has to be moved to a separate file. I was probably being overly cautious about the ifdef. CONFIG_TCG is not as tricky as target-specific macros that can't be used in any header. -- Eduardo