On Thu, Jun 27, 2019 at 09:28:42PM -0300, Eduardo Habkost wrote:
> This will make unversioned CPU models behavior depend on the
> machine type:
>
> * "pc-*-4.0" and older will not report them as aliases.
> This is done to keep compatibility with older QEMU versions
> after management software starts translating aliases.
>
> * "pc-*-4.1" will translate unversioned CPU models to -v1.
> This is done to keep compatibility with existing management
> software, that still relies on CPU model runnability promises.
>
> * "none" will translate unversioned CPU models to their latest
> version. This is planned become the default in future machine
> types (probably in pc-*-4.3).
>
> Signed-off-by: Eduardo Habkost <ehabk...@redhat.com>
> ---
> Patch v1 was "[PATCH 4/6] i386: Infrastructure for versioned CPU
> models", and was split into multiple patches.
>
> Changes v1 -> v2:
> * Make version numbers simple integers, completely independent
> from machine type versions
> * New X86CPUVersion typedef
> * New CPU_VERSION_* defines to make X86CPUModel::version
> semantics clearer
> ---
> include/hw/i386/pc.h | 3 +
> target/i386/cpu.h | 12 ++
> hw/i386/pc.c | 3 +
> hw/i386/pc_piix.c | 4 +
> hw/i386/pc_q35.c | 4 +
> target/i386/cpu.c | 52 ++++++++-
> tests/acceptance/x86_cpu_model_versions.py | 126 +++++++++++++++++++++
> 7 files changed, 203 insertions(+), 1 deletion(-)
>
> diff --git a/include/hw/i386/pc.h b/include/hw/i386/pc.h
> index ee79d71ccc..1946c1023f 100644
> --- a/include/hw/i386/pc.h
> +++ b/include/hw/i386/pc.h
> @@ -109,6 +109,9 @@ typedef struct PCMachineClass {
>
> /* Compat options: */
>
> + /* Default CPU model version. See x86_cpu_set_default_version(). */
> + int default_cpu_version;
> +
> /* ACPI compat: */
> bool has_acpi_build;
> bool rsdp_in_ram;
> diff --git a/target/i386/cpu.h b/target/i386/cpu.h
> index 12bc3cd4a8..05393cf9d1 100644
> --- a/target/i386/cpu.h
> +++ b/target/i386/cpu.h
> @@ -1934,11 +1934,23 @@ void x86_cpu_change_kvm_default(const char *prop,
> const char *value);
> /* Resolve to latest CPU version */
> #define CPU_VERSION_LATEST -1
>
> +/*
> + * Resolve to version defined by current machine type.
> + * See x86_cpu_set_default_version()
> + */
> +#define CPU_VERSION_AUTO -2
> +
> /* Don't resolve to any versioned CPU models, like old QEMU versions */
> #define CPU_VERSION_LEGACY 0
>
> typedef int X86CPUVersion;
>
> +/*
> + * Set default CPU model version for CPU models having
> + * version == CPU_VERSION_AUTO.
> + */
> +void x86_cpu_set_default_version(X86CPUVersion version);
> +
> /* Return name of 32-bit register, from a R_* constant */
> const char *get_register_name_32(unsigned int reg);
>
> diff --git a/hw/i386/pc.c b/hw/i386/pc.c
> index 3f0f221a5b..1df569620a 100644
> --- a/hw/i386/pc.c
> +++ b/hw/i386/pc.c
> @@ -1649,6 +1649,9 @@ void pc_cpus_init(PCMachineState *pcms)
> const CPUArchIdList *possible_cpus;
> MachineState *ms = MACHINE(pcms);
> MachineClass *mc = MACHINE_GET_CLASS(pcms);
> + PCMachineClass *pcmc = PC_MACHINE_CLASS(mc);
> +
> + x86_cpu_set_default_version(pcmc->default_cpu_version);
>
> /* Calculates the limit to CPU APIC ID values
> *
> diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c
> index c07c4a5b38..0a069bff54 100644
> --- a/hw/i386/pc_piix.c
> +++ b/hw/i386/pc_piix.c
> @@ -430,9 +430,11 @@ static void pc_i440fx_machine_options(MachineClass *m)
>
> static void pc_i440fx_4_1_machine_options(MachineClass *m)
> {
> + PCMachineClass *pcmc = PC_MACHINE_CLASS(m);
> pc_i440fx_machine_options(m);
> m->alias = "pc";
> m->is_default = 1;
> + pcmc->default_cpu_version = 1;
> }
>
> DEFINE_I440FX_MACHINE(v4_1, "pc-i440fx-4.1", NULL,
> @@ -440,9 +442,11 @@ DEFINE_I440FX_MACHINE(v4_1, "pc-i440fx-4.1", NULL,
>
> static void pc_i440fx_4_0_machine_options(MachineClass *m)
> {
> + PCMachineClass *pcmc = PC_MACHINE_CLASS(m);
> pc_i440fx_4_1_machine_options(m);
> m->alias = NULL;
> m->is_default = 0;
> + pcmc->default_cpu_version = CPU_VERSION_LEGACY;
> compat_props_add(m->compat_props, hw_compat_4_0, hw_compat_4_0_len);
> compat_props_add(m->compat_props, pc_compat_4_0, pc_compat_4_0_len);
> }
> diff --git a/hw/i386/pc_q35.c b/hw/i386/pc_q35.c
> index 57232aed6b..397e1fdd2f 100644
> --- a/hw/i386/pc_q35.c
> +++ b/hw/i386/pc_q35.c
> @@ -367,8 +367,10 @@ static void pc_q35_machine_options(MachineClass *m)
>
> static void pc_q35_4_1_machine_options(MachineClass *m)
> {
> + PCMachineClass *pcmc = PC_MACHINE_CLASS(m);
> pc_q35_machine_options(m);
> m->alias = "q35";
> + pcmc->default_cpu_version = 1;
How will this work in future if we need to introduce a v2 of some,
but not all CPU models, and then further a v3 of some others.
Can we select Haswell-v1, Skylake-Server-v2, CascadeLake-v3
as defaults in some way ?
Regards,
Daniel
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