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Re: [PATCH v2 1/2] Introduce (x86) CPU model deprecation API
From: |
Robert Hoo |
Subject: |
Re: [PATCH v2 1/2] Introduce (x86) CPU model deprecation API |
Date: |
Sun, 28 Jun 2020 19:30:55 +0800 |
Hi, Ping for comments:)
On Thu, 2020-06-11 at 10:47 +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.
>
> Changes in 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.
>
> Signed-off-by: Robert Hoo <robert.hu@linux.intel.com>
> ---
> hw/core/machine.c | 11 +++++++++--
> include/hw/core/cpu.h | 1 +
> qapi/machine-target.json | 7 ++++++-
> target/i386/cpu.c | 45
> +++++++++++++++++++++++++++++++++++++++++++--
> 4 files changed, 59 insertions(+), 5 deletions(-)
>
> diff --git a/hw/core/machine.c b/hw/core/machine.c
> index bb3a7b1..9318964 100644
> --- a/hw/core/machine.c
> +++ b/hw/core/machine.c
> @@ -1083,6 +1083,8 @@ 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);
> + CPUClass *cc;
>
> if (machine->ram_memdev_id) {
> Object *o;
> @@ -1102,11 +1104,10 @@ 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.
> @@ -1129,6 +1130,12 @@ void machine_run_board_init(MachineState
> *machine)
> }
> }
>
> + /* Check if CPU type is deprecated and warn if so */
> + cc = CPU_CLASS(oc);
> + if (cc->deprecation_check) {
> + cc->deprecation_check(oc);
> + }
> +
> machine_class->init(machine);
> }
>
> diff --git a/include/hw/core/cpu.h b/include/hw/core/cpu.h
> index 497600c..1ca47dc 100644
> --- a/include/hw/core/cpu.h
> +++ b/include/hw/core/cpu.h
> @@ -218,6 +218,7 @@ typedef 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);
> + void (*deprecation_check)(ObjectClass *oc);
>
> /* Keep non-pointer data at the end to minimize holes. */
> int gdb_num_core_regs;
> diff --git a/qapi/machine-target.json b/qapi/machine-target.json
> index f2c8294..c24f506 100644
> --- a/qapi/machine-target.json
> +++ b/qapi/machine-target.json
> @@ -285,6 +285,10 @@
> # 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 5.1)
> +#
> # @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
> @@ -309,7 +313,8 @@
> '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 ba05da3..0d8638a 100644
> --- a/target/i386/cpu.c
> +++ b/target/i386/cpu.c
> @@ -1599,6 +1599,7 @@ typedef struct X86CPUVersionDefinition {
> const char *alias;
> const char *note;
> PropValue *props;
> + bool deprecated;
> } X86CPUVersionDefinition;
>
> /* Base definition for a CPU model */
> @@ -1638,6 +1639,11 @@ struct X86CPUModel {
> * This matters only for "-cpu help" and query-cpu-definitions
> */
> bool is_alias;
> + /*
> + * If true, this model is deprecated, and may be removed in the
> future.
> + * Trying to use it now will cause a warning.
> + */
> + bool deprecated;
> };
>
> /* Get full model name for CPU version */
> @@ -4128,8 +4134,7 @@ static X86CPUVersion
> x86_cpu_model_resolve_version(const X86CPUModel *model)
> X86CPUVersion v = model->version;
> if (v == CPU_VERSION_AUTO) {
> v = default_cpu_version;
> - }
> - if (v == CPU_VERSION_LATEST) {
> + } else if (v == CPU_VERSION_LATEST) {
> return x86_cpu_model_last_version(model);
> }
> return v;
> @@ -4975,6 +4980,7 @@ 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;
> + info->deprecated = cc->model ? cc->model->deprecated : false;
> /*
> * Old machine types won't report aliases, so that alias
> translation
> * doesn't break compatibility with previous QEMU versions.
> @@ -5411,6 +5417,7 @@ static void
> x86_register_cpudef_types(X86CPUDefinition *def)
> m->cpudef = def;
> m->version = vdef->version;
> m->note = vdef->note;
> + m->deprecated = vdef->deprecated;
> x86_register_cpu_model_type(name, m);
>
> if (vdef->alias) {
> @@ -5418,6 +5425,8 @@ static void
> x86_register_cpudef_types(X86CPUDefinition *def)
> am->cpudef = def;
> am->version = vdef->version;
> am->is_alias = true;
> + am->note = vdef->note;
> + am->deprecated = vdef->deprecated;
> x86_register_cpu_model_type(vdef->alias, am);
> }
> }
> @@ -7233,6 +7242,37 @@ static Property x86_cpu_properties[] = {
> DEFINE_PROP_END_OF_LIST()
> };
>
> +static void x86_cpu_deprecation_check(ObjectClass *oc)
> +{
> + X86CPUClass *xcc = X86_CPU_CLASS(oc);
> + X86CPUVersion effective_version;
> + const X86CPUVersionDefinition *vdef;
> +
> + if (xcc->model == NULL) {
> + return;
> + }
> +
> + if (xcc->model->version == CPU_VERSION_LEGACY) {
> + /* Treat legacy version as v1 */
> + effective_version = 1;
> + } else {
> + effective_version = x86_cpu_model_resolve_version(xcc-
> >model);
> + }
> +
> + vdef = xcc->model->cpudef->versions;
> +
> + if (vdef == NULL) {
> + return;
> + } else {
> + if (vdef[effective_version - 1].deprecated) {
> + warn_report("Effective CPU model '%s' -- %s",
> + x86_cpu_versioned_model_name(xcc->model-
> >cpudef,\
> + effective_version),
> + vdef[effective_version - 1].note);
> + }
> + }
> +}
> +
> static void x86_cpu_common_class_init(ObjectClass *oc, void *data)
> {
> X86CPUClass *xcc = X86_CPU_CLASS(oc);
> @@ -7291,6 +7331,7 @@ static void
> x86_cpu_common_class_init(ObjectClass *oc, void *data)
> cc->tlb_fill = x86_cpu_tlb_fill;
> #endif
> cc->disas_set_info = x86_disas_set_info;
> + cc->deprecation_check = x86_cpu_deprecation_check;
>
> dc->user_creatable = true;
> }