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 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 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@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> --- Changes v11 -> v12: * Remove unnecessary entries from .gitignore * Fix indentation of x86_cpu_get_feature_words() declaration * Rebase on top of qom-cpu-next (commit bd87d2a - target-i386: Use FeatureWord loop on filter_features_for_kvm()) Changes v1 -> v2 (series marked as v11): * 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 --- Makefile.objs | 7 +++++- qapi-schema.json | 32 +++++++++++++++++++++++++ target-i386/cpu.c | 70 +++++++++++++++++++++++++++++++++++++++++++++---------- 3 files changed, 96 insertions(+), 13 deletions(-) diff --git a/Makefile.objs b/Makefile.objs index fcb303a..286ce06 100644 --- a/Makefile.objs +++ b/Makefile.objs @@ -79,10 +79,15 @@ 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 7797400..199744a 100644 --- a/qapi-schema.json +++ b/qapi-schema.json @@ -3587,3 +3587,35 @@ ## {'command': 'query-command-line-options', 'data': { '*option': 'str' }, 'returns': ['CommandLineOptionInfo'] } + +## +# @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 a39b364..3857514 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" @@ -195,23 +197,34 @@ 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 } +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 @@ -1405,6 +1418,36 @@ static void x86_cpuid_set_apic_id(Object *obj, Visitor *v, void *opaque, cpu->env.cpuid_apic_id = value; } +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; + 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 = &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; @@ -2396,6 +2439,9 @@ static void x86_cpu_initfn(Object *obj) object_property_add(obj, "apic-id", "int", x86_cpuid_get_apic_id, x86_cpuid_set_apic_id, 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

This property will contain all the features that were removed from the CPU because they are not supported by the host. This way, libvirt or other management tools can emulate the check/enforce behavior by checking if filtered-properties is all zeroes, before starting the guest. Example output where some features were missing: $ ./install/bin/qemu-system-x86_64 -enable-kvm -cpu Haswell,check -S -qmp unix:/tmp/m,server,nowait warning: host doesn't support requested feature: CPUID.01H:ECX.fma [bit 12] warning: host doesn't support requested feature: CPUID.01H:ECX.movbe [bit 22] warning: host doesn't support requested feature: CPUID.01H:ECX.tsc-deadline [bit 24] warning: host doesn't support requested feature: CPUID.01H:ECX.xsave [bit 26] warning: host doesn't support requested feature: CPUID.01H:ECX.avx [bit 28] warning: host doesn't support requested feature: CPUID.07H:EBX.fsgsbase [bit 0] warning: host doesn't support requested feature: CPUID.07H:EBX.bmi1 [bit 3] warning: host doesn't support requested feature: CPUID.07H:EBX.hle [bit 4] warning: host doesn't support requested feature: CPUID.07H:EBX.avx2 [bit 5] warning: host doesn't support requested feature: CPUID.07H:EBX.smep [bit 7] warning: host doesn't support requested feature: CPUID.07H:EBX.bmi2 [bit 8] warning: host doesn't support requested feature: CPUID.07H:EBX.erms [bit 9] warning: host doesn't support requested feature: CPUID.07H:EBX.invpcid [bit 10] warning: host doesn't support requested feature: CPUID.07H:EBX.rtm [bit 11] [...] $ ./QMP/qmp --path=/tmp/m qom-get --path=/machine/unattached/device[1] --property=filtered-features 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: 0 item[4].cpuid-register: EDX item[4].cpuid-input-eax: 2147483649 item[4].features: 0 item[5].cpuid-register: EBX item[5].cpuid-input-eax: 7 item[5].features: 4025 item[5].cpuid-input-ecx: 0 item[6].cpuid-register: ECX item[6].cpuid-input-eax: 1 item[6].features: 356519936 item[7].cpuid-register: EDX item[7].cpuid-input-eax: 1 item[7].features: 0 Example output when no feature is missing: $ ./install/bin/qemu-system-x86_64 -enable-kvm -cpu Nehalem,enforce -S -qmp unix:/tmp/m,server,nowait [...] $ ./QMP/qmp --path=/tmp/m qom-get --path=/machine/unattached/device[1] --property=filtered-features 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: 0 item[4].cpuid-register: EDX item[4].cpuid-input-eax: 2147483649 item[4].features: 0 item[5].cpuid-register: EBX item[5].cpuid-input-eax: 7 item[5].features: 0 item[5].cpuid-input-ecx: 0 item[6].cpuid-register: ECX item[6].cpuid-input-eax: 1 item[6].features: 0 item[7].cpuid-register: EDX item[7].cpuid-input-eax: 1 item[7].features: 0 Signed-off-by: Eduardo Habkost <ehabkost@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> --- Changes v11 -> v12: * Rebase on top of qom-cpu-next (commit bd87d2a - target-i386: Use FeatureWord loop on filter_features_for_kvm()) --- target-i386/cpu.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/target-i386/cpu.c b/target-i386/cpu.c index 38793bc..eb1825b 100644 --- a/target-i386/cpu.c +++ b/target-i386/cpu.c @@ -1418,11 +1418,11 @@ static void x86_cpuid_set_apic_id(Object *obj, Visitor *v, void *opaque, cpu->env.cpuid_apic_id = value; } +/* Generic getter for "feature-words" and "filtered-features" properties */ 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; + uint32_t *array = (uint32_t *)opaque; FeatureWord w; Error *err = NULL; X86CPUFeatureWordInfo word_infos[FEATURE_WORDS] = { }; @@ -1436,7 +1436,7 @@ static void x86_cpu_get_feature_words(Object *obj, Visitor *v, void *opaque, 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; - qwi->features = env->features[w]; + qwi->features = array[w]; /* List will be in reverse order, but order shouldn't matter */ list_entries[w].next = list; @@ -2444,7 +2444,10 @@ static void x86_cpu_initfn(Object *obj) x86_cpuid_set_apic_id, NULL, NULL, NULL); object_property_add(obj, "feature-words", "X86CPUFeatureWordInfo", x86_cpu_get_feature_words, - NULL, NULL, NULL, NULL); + NULL, NULL, (void *)env->features, NULL); + object_property_add(obj, "filtered-features", "X86CPUFeatureWordInfo", + x86_cpu_get_feature_words, + NULL, NULL, (void *)cpu->filtered_features, NULL); env->cpuid_apic_id = x86_cpu_apic_id_from_index(cs->cpu_index); -- 1.8.1.4