On Mon, 22 Apr 2013 16:00:17 -0300
Eduardo Habkost <ehabkost@xxxxxxxxxx> wrote:
> This property will be useful for libvirt, as libvirt already has logic
> based on low-level feature bits (not feature names), so it will be
> really easy to convert the current libvirt logic to something using the
> "feature-words" property.
>
> The property will have two main use cases:
> - Checking host capabilities, by checking the features of the "host"
> CPU model
> - Checking which features are enabled on each CPU model
patch doesn't apply to current qom-cpu, more comments below.
>
> Example output:
>
> $ ./QMP/qmp --path=/tmp/m qom-get --path=/machine/unattached/device[1] --property=feature-words
> item[0].cpuid-register: EDX
> item[0].cpuid-input-eax: 2147483658
> item[0].features: 0
> item[1].cpuid-register: EAX
> item[1].cpuid-input-eax: 1073741825
> item[1].features: 0
> item[2].cpuid-register: EDX
> item[2].cpuid-input-eax: 3221225473
> item[2].features: 0
> item[3].cpuid-register: ECX
> item[3].cpuid-input-eax: 2147483649
> item[3].features: 101
> item[4].cpuid-register: EDX
> item[4].cpuid-input-eax: 2147483649
> item[4].features: 563346425
> item[5].cpuid-register: EBX
> item[5].cpuid-input-eax: 7
> item[5].features: 0
> item[5].cpuid-input-ecx: 0
could item be represented as CPUID function in format used in Intel's SDM?
item[5].CPUID: EAX=7h,ECX=0h
item[5].EBX: 0
item[5].EAX: 0
for simplicity/uniformity ECX could be not optional, always present, and
ignored when not needed.
> item[6].cpuid-register: ECX
> item[6].cpuid-input-eax: 1
> item[6].features: 2155880449
> item[7].cpuid-register: EDX
> item[7].cpuid-input-eax: 1
> item[7].features: 126614521
>
> Signed-off-by: Eduardo Habkost <ehabkost@xxxxxxxxxx>
> ---
> Changes v1 -> v2:
> * Merge the non-qapi and qapi patches, to keep series simpler
> * Use the feature word array series as base, so we don't have
> to set the feature word values one-by-one in the code
> * Change type name of property from "x86-cpu-feature-words" to
> "X86CPUFeatureWordInfo"
> * Remove cpu-qapi-schema.json and simply add the type definitions
> to qapi-schema.json, to keep the changes simpler
> * This required compiling qapi-types.o and qapi-visit.o into
> *-user as well
> ---
> .gitignore | 2 ++
> Makefile.objs | 7 +++++-
> qapi-schema.json | 31 ++++++++++++++++++++++++
> target-i386/cpu.c | 70 +++++++++++++++++++++++++++++++++++++++++++++----------
> 4 files changed, 97 insertions(+), 13 deletions(-)
>
> diff --git a/.gitignore b/.gitignore
> index 487813a..71408e3 100644
> --- a/.gitignore
> +++ b/.gitignore
> @@ -21,6 +21,8 @@ linux-headers/asm
> qapi-generated
> qapi-types.[ch]
> qapi-visit.[ch]
> +cpu-qapi-types.[ch]
> +cpu-qapi-visit.[ch]
still needed?
> qmp-commands.h
> qmp-marshal.c
> qemu-doc.html
> diff --git a/Makefile.objs b/Makefile.objs
> index a473348..1835d37 100644
> --- a/Makefile.objs
> +++ b/Makefile.objs
> @@ -78,10 +78,15 @@ common-obj-$(CONFIG_SMARTCARD_NSS) += $(libcacard-y)
> ######################################################################
> # qapi
>
> -common-obj-y += qmp-marshal.o qapi-visit.o qapi-types.o
> +common-obj-y += qmp-marshal.o
> common-obj-y += qmp.o hmp.o
> endif
>
> +######################################################################
> +# some qapi visitors are used by both system and user emulation:
> +
> +common-obj-y += qapi-visit.o qapi-types.o
> +
> #######################################################################
> # Target-independent parts used in system and user emulation
> common-obj-y += qemu-log.o
> diff --git a/qapi-schema.json b/qapi-schema.json
> index 751d3c2..424434f 100644
> --- a/qapi-schema.json
> +++ b/qapi-schema.json
> @@ -3505,3 +3505,34 @@
> '*asl_compiler_rev': 'uint32',
> '*file': 'str',
> '*data': 'str' }}
> +
> +# @X86CPURegister32
> +#
> +# A X86 32-bit register
> +#
> +# Since: 1.5
> +##
> +{ 'enum': 'X86CPURegister32',
> + 'data': [ 'EAX', 'EBX', 'ECX', 'EDX', 'ESP', 'EBP', 'ESI', 'EDI' ] }
> +
> +##
> +# @X86CPUFeatureWordInfo
> +#
> +# Information about a X86 CPU feature word
> +#
> +# @cpuid-input-eax: Input EAX value for CPUID instruction for that feature word
> +#
> +# @cpuid-input-ecx: #optional Input ECX value for CPUID instruction for that
> +# feature word
> +#
> +# @cpuid-register: Output register containing the feature bits
> +#
> +# @features: value of output register, containing the feature bits
> +#
> +# Since: 1.5
> +##
> +{ 'type': 'X86CPUFeatureWordInfo',
> + 'data': { 'cpuid-input-eax': 'int',
> + '*cpuid-input-ecx': 'int',
> + 'cpuid-register': 'X86CPURegister32',
> + 'features': 'int' } }
> diff --git a/target-i386/cpu.c b/target-i386/cpu.c
> index 314931e..757749c 100644
> --- a/target-i386/cpu.c
> +++ b/target-i386/cpu.c
> @@ -30,6 +30,8 @@
> #include "qemu/config-file.h"
> #include "qapi/qmp/qerror.h"
>
> +#include "qapi-types.h"
> +#include "qapi-visit.h"
> #include "qapi/visitor.h"
> #include "sysemu/arch_init.h"
>
> @@ -194,23 +196,34 @@ static FeatureWordInfo feature_word_info[FEATURE_WORDS] = {
> },
> };
>
> +typedef struct X86RegisterInfo32 {
> + /* Name of register */
> + const char *name;
> + /* QAPI enum value register */
> + X86CPURegister32 qapi_enum;
> +} X86RegisterInfo32;
> +
> +#define REGISTER(reg) \
> + [R_##reg] = { .name = #reg, .qapi_enum = X86_C_P_U_REGISTER32_##reg }
^^^^
Using auto-generated names like this probably is very fragile.
> +X86RegisterInfo32 x86_reg_info_32[CPU_NB_REGS32] = {
> + REGISTER(EAX),
> + REGISTER(ECX),
> + REGISTER(EDX),
> + REGISTER(EBX),
> + REGISTER(ESP),
> + REGISTER(EBP),
> + REGISTER(ESI),
> + REGISTER(EDI),
> +};
> +#undef REGISTER
> +
> +
> const char *get_register_name_32(unsigned int reg)
> {
> - static const char *reg_names[CPU_NB_REGS32] = {
> - [R_EAX] = "EAX",
> - [R_ECX] = "ECX",
> - [R_EDX] = "EDX",
> - [R_EBX] = "EBX",
> - [R_ESP] = "ESP",
> - [R_EBP] = "EBP",
> - [R_ESI] = "ESI",
> - [R_EDI] = "EDI",
> - };
> -
> if (reg > CPU_NB_REGS32) {
> return NULL;
> }
> - return reg_names[reg];
> + return x86_reg_info_32[reg].name;
> }
>
> /* collects per-function cpuid data
> @@ -1360,6 +1373,36 @@ static void x86_cpuid_set_tsc_freq(Object *obj, Visitor *v, void *opaque,
> cpu->env.tsc_khz = value / 1000;
> }
>
> +static void x86_cpu_get_feature_words(Object *obj, Visitor *v, void *opaque,
> + const char *name, Error **errp)
> +{
> + X86CPU *cpu = X86_CPU(obj);
> + CPUX86State *env = &cpu->env;
> + FeatureWord w;
> + Error *err = NULL;
> + X86CPUFeatureWordInfo word_infos[FEATURE_WORDS] = { };
> + X86CPUFeatureWordInfoList list_entries[FEATURE_WORDS] = { };
> + X86CPUFeatureWordInfoList *list = NULL;
> +
> + for (w = 0; w < FEATURE_WORDS; w++) {
> + FeatureWordInfo *wi = &feature_word_info[w];
> + X86CPUFeatureWordInfo *qwi = &word_infos[w];
> + qwi->cpuid_input_eax = wi->cpuid_eax;
> + qwi->has_cpuid_input_ecx = wi->cpuid_needs_ecx;
> + qwi->cpuid_input_ecx = wi->cpuid_ecx;
> + qwi->cpuid_register = x86_reg_info_32[wi->cpuid_reg].qapi_enum;
Is there way not to use qapi_enum at all and use name instead?
> + qwi->features = env->features[w];
> +
> + /* List will be in reverse order, but order shouldn't matter */
> + list_entries[w].next = list;
> + list_entries[w].value = &word_infos[w];
list_entries[w].value = qwi;
> + list = &list_entries[w];
> + }
> +
> + visit_type_X86CPUFeatureWordInfoList(v, &list, "feature-words", &err);
> + error_propagate(errp, err);
> +}
> +
> static int cpu_x86_find_by_name(x86_def_t *x86_cpu_def, const char *name)
> {
> x86_def_t *def;
> @@ -2348,6 +2391,9 @@ static void x86_cpu_initfn(Object *obj)
> object_property_add(obj, "tsc-frequency", "int",
> x86_cpuid_get_tsc_freq,
> x86_cpuid_set_tsc_freq, NULL, NULL, NULL);
> + object_property_add(obj, "feature-words", "X86CPUFeatureWordInfo",
> + x86_cpu_get_feature_words,
> + NULL, NULL, NULL, NULL);
>
> env->cpuid_apic_id = x86_cpu_apic_id_from_index(cs->cpu_index);
>
> --
> 1.8.1.4
>
>
--
Regards,
Igor
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