On Tue, Sep 22, 2020 at 03:14:14PM +0800, Robert Hoo wrote:
> Complement versioned CPU model framework with the ability of marking some
> versions deprecated. When that CPU model is chosen, get some warning. The
> warning message is customized, e.g. telling in which future QEMU version will
> it be obsoleted.
> The deprecation message will also appear by x86_cpu_list_entry(), e.g. '-cpu
> help'.
> QMP 'query-cpu-definitions' will also return a bool value indicating the
> deprecation status.
>
> Signed-off-by: Robert Hoo <robert...@linux.intel.com>
> ---
> Changelog
> v4:
> Move deprecation_note from X86CPUModel to X86CPUDefinition, to make it
> simple. Also, simplify 2 fields (deprecation_note and deprecated) into 1
> (deprecation_note).
>
> v3:
> Make the deprecation implementation CPUClass generic.
>
> v2:
> Move deprecation check from parse_cpu_option() to machine_run_board_init(), so
> that it can cover implicit cpu_type assignment cases.
> Add qapi new member documentation. Thanks Eric for comment and guidance on
> qapi.
>
> ---
> hw/core/machine.c | 12 ++++++++++--
> include/hw/core/cpu.h | 3 +++
> qapi/machine-target.json | 7 ++++++-
> target/i386/cpu.c | 8 ++++++++
> 4 files changed, 27 insertions(+), 3 deletions(-)
>
> diff --git a/hw/core/machine.c b/hw/core/machine.c
> index ea26d61..67fff0b 100644
> --- a/hw/core/machine.c
> +++ b/hw/core/machine.c
> @@ -1095,6 +1095,8 @@ MemoryRegion *machine_consume_memdev(MachineState
> *machine,
> void machine_run_board_init(MachineState *machine)
> {
> MachineClass *machine_class = MACHINE_GET_CLASS(machine);
> + ObjectClass *oc = object_class_by_name(machine->cpu_type);
machine->cpu_type can be NULL...
> + CPUClass *cc;
>
> if (machine->ram_memdev_id) {
> Object *o;
> @@ -1114,11 +1116,10 @@ void machine_run_board_init(MachineState *machine)
> * specified a CPU with -cpu check here that the user CPU is supported.
> */
> if (machine_class->valid_cpu_types && machine->cpu_type) {
> - ObjectClass *class = object_class_by_name(machine->cpu_type);
> int i;
>
> for (i = 0; machine_class->valid_cpu_types[i]; i++) {
> - if (object_class_dynamic_cast(class,
> + if (object_class_dynamic_cast(oc,
>
> machine_class->valid_cpu_types[i])) {
> /* The user specificed CPU is in the valid field, we are
> * good to go.
> @@ -1141,6 +1142,13 @@ void machine_run_board_init(MachineState *machine)
> }
> }
>
> + /* Check if CPU type is deprecated and warn if so */
> + cc = CPU_CLASS(oc);
> + if (cc->deprecation_note) {
...so this will crash.
I've changed this to "if (cc && cc->deprecation_note)".
> + warn_report("CPU model %s is deprecated -- %s", machine->cpu_type,
> + cc->deprecation_note);
> + }
> +
> machine_class->init(machine);
> }
>
> diff --git a/include/hw/core/cpu.h b/include/hw/core/cpu.h
> index 99dc33f..c40c29d 100644
> --- a/include/hw/core/cpu.h
> +++ b/include/hw/core/cpu.h
> @@ -155,6 +155,8 @@ struct TranslationBlock;
> * @disas_set_info: Setup architecture specific components of disassembly
> info
> * @adjust_watchpoint_address: Perform a target-specific adjustment to an
> * address before attempting to match it against watchpoints.
> + * @deprecation_note: If this CPUClass is deprecated, this field provides
> + * related information.
> *
> * Represents a CPU family or model.
> */
> @@ -221,6 +223,7 @@ struct CPUClass {
> 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;
> diff --git a/qapi/machine-target.json b/qapi/machine-target.json
> index 698850c..fec3bb8 100644
> --- a/qapi/machine-target.json
> +++ b/qapi/machine-target.json
> @@ -286,6 +286,10 @@
> # in the VM configuration, because aliases may stop being
> # migration-safe in the future (since 4.1)
> #
> +# @deprecated: If true, this CPU model is deprecated and may be removed in
> +# in some future version of QEMU according to the QEMU
> deprecation
> +# policy. (since 5.2)
> +#
> # @unavailable-features is a list of QOM property names that
> # represent CPU model attributes that prevent the CPU from running.
> # If the QOM property is read-only, that means there's no known
> @@ -310,7 +314,8 @@
> 'static': 'bool',
> '*unavailable-features': [ 'str' ],
> 'typename': 'str',
> - '*alias-of' : 'str' },
> + '*alias-of' : 'str',
> + 'deprecated' : 'bool' },
> 'if': 'defined(TARGET_PPC) || defined(TARGET_ARM) || defined(TARGET_I386)
> || defined(TARGET_S390X) || defined(TARGET_MIPS)' }
>
> ##
> diff --git a/target/i386/cpu.c b/target/i386/cpu.c
> index 1c58f76..323c7e3 100644
> --- a/target/i386/cpu.c
> +++ b/target/i386/cpu.c
> @@ -1633,6 +1633,7 @@ typedef struct X86CPUDefinition {
> * If NULL, version 1 will be registered automatically.
> */
> const X86CPUVersionDefinition *versions;
> + const char *deprecation_note;
> } X86CPUDefinition;
>
> /* Reference to a specific CPU model version */
> @@ -4992,6 +4993,11 @@ static void x86_cpu_definition_entry(gpointer data,
> gpointer user_data)
> info->migration_safe = cc->migration_safe;
> info->has_migration_safe = true;
> info->q_static = cc->static_model;
> + if (cc->model && cc->model->cpudef->deprecation_note) {
> + info->deprecated = true;
> + } else {
> + info->deprecated = false;
> + }
> /*
> * Old machine types won't report aliases, so that alias translation
> * doesn't break compatibility with previous QEMU versions.
> @@ -5382,9 +5388,11 @@ static void x86_cpu_cpudef_class_init(ObjectClass *oc,
> void *data)
> {
> X86CPUModel *model = data;
> X86CPUClass *xcc = X86_CPU_CLASS(oc);
> + CPUClass *cc = CPU_CLASS(oc);
>
> xcc->model = model;
> xcc->migration_safe = true;
> + cc->deprecation_note = model->cpudef->deprecation_note;
> }
>
> static void x86_register_cpu_model_type(const char *name, X86CPUModel *model)
> --
> 1.8.3.1
>
>
--
Eduardo
