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target-i386: Automatically set level/xlevel/xlevel2 when needed
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Instead of requiring users and management software to be aware of
required CPUID level/xlevel/xlevel2 values for each feature,
automatically increase those values when features need them.

This was already done for CPUID[7].EBX, and is now made generic
for all CPUID feature flags. Unit test included, to make sure we
don't break ABI on older machine-types and don't mess with the
CPUID level values if they are explicitly set by the user.

Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
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@ehabkost
ehabkost committed Sep 27, 2016
1 parent df3e9af commit c39c0ed
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Showing 4 changed files with 133 additions and 13 deletions.
5 changes: 5 additions & 0 deletions include/hw/i386/pc.h
View file
Expand Up @@ -374,6 +374,11 @@ bool e820_get_entry(int, uint32_t, uint64_t *, uint64_t *);
.driver = TYPE_X86_CPU,\
.property = "l3-cache",\
.value = "off",\
},\
{\
.driver = TYPE_X86_CPU,\
.property = "full-cpuid-auto-level",\
.value = "off",\
},

#define PC_COMPAT_2_6 \
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84 changes: 74 additions & 10 deletions target-i386/cpu.c
View file
Expand Up @@ -1643,9 +1643,12 @@ static void host_x86_cpu_initfn(Object *obj)

/* If KVM is disabled, x86_cpu_realizefn() will report an error later */
if (kvm_enabled()) {
env->cpuid_level = kvm_arch_get_supported_cpuid(s, 0x0, 0, R_EAX);
env->cpuid_xlevel = kvm_arch_get_supported_cpuid(s, 0x80000000, 0, R_EAX);
env->cpuid_xlevel2 = kvm_arch_get_supported_cpuid(s, 0xC0000000, 0, R_EAX);
env->cpuid_min_level =
kvm_arch_get_supported_cpuid(s, 0x0, 0, R_EAX);
env->cpuid_min_xlevel =
kvm_arch_get_supported_cpuid(s, 0x80000000, 0, R_EAX);
env->cpuid_min_xlevel2 =
kvm_arch_get_supported_cpuid(s, 0xC0000000, 0, R_EAX);

if (lmce_supported()) {
object_property_set_bool(OBJECT(cpu), true, "lmce", &error_abort);
Expand Down Expand Up @@ -2208,11 +2211,13 @@ static void x86_cpu_load_def(X86CPU *cpu, X86CPUDefinition *def, Error **errp)
char host_vendor[CPUID_VENDOR_SZ + 1];
FeatureWord w;

object_property_set_int(OBJECT(cpu), def->level, "level", errp);
/* CPU models only set _minimum_ values for level/xlevel: */
object_property_set_int(OBJECT(cpu), def->level, "min-level", errp);
object_property_set_int(OBJECT(cpu), def->xlevel, "min-xlevel", errp);

object_property_set_int(OBJECT(cpu), def->family, "family", errp);
object_property_set_int(OBJECT(cpu), def->model, "model", errp);
object_property_set_int(OBJECT(cpu), def->stepping, "stepping", errp);
object_property_set_int(OBJECT(cpu), def->xlevel, "xlevel", errp);
object_property_set_str(OBJECT(cpu), def->model_id, "model-id", errp);
for (w = 0; w < FEATURE_WORDS; w++) {
env->features[w] = def->features[w];
Expand Down Expand Up @@ -2951,6 +2956,38 @@ static uint32_t x86_host_phys_bits(void)
return host_phys_bits;
}

static void x86_cpu_adjust_level(X86CPU *cpu, uint32_t *min, uint32_t value)
{
if (*min < value) {
*min = value;
}
}

/* Increase cpuid_min_{level,xlevel,xlevel2} automatically, if appropriate */
static void x86_cpu_adjust_feat_level(X86CPU *cpu, FeatureWord w)
{
CPUX86State *env = &cpu->env;
FeatureWordInfo *fi = &feature_word_info[w];
uint32_t eax = fi->cpuid_eax;
uint32_t region = eax & 0xF0000000;

if (!env->features[w]) {
return;
}

switch (region) {
case 0x00000000:
x86_cpu_adjust_level(cpu, &env->cpuid_min_level, eax);
break;
case 0x80000000:
x86_cpu_adjust_level(cpu, &env->cpuid_min_xlevel, eax);
break;
case 0xC0000000:
x86_cpu_adjust_level(cpu, &env->cpuid_min_xlevel2, eax);
break;
}
}

#define IS_INTEL_CPU(env) ((env)->cpuid_vendor1 == CPUID_VENDOR_INTEL_1 && \
(env)->cpuid_vendor2 == CPUID_VENDOR_INTEL_2 && \
(env)->cpuid_vendor3 == CPUID_VENDOR_INTEL_3)
Expand Down Expand Up @@ -2996,8 +3033,31 @@ static void x86_cpu_realizefn(DeviceState *dev, Error **errp)
cpu->env.features[w] &= ~minus_features[w];
}

if (env->features[FEAT_7_0_EBX] && env->cpuid_level < 7) {
env->cpuid_level = 7;

/* CPUID[EAX=7,ECX=0].EBX always increased level automatically: */
x86_cpu_adjust_feat_level(cpu, FEAT_7_0_EBX);
if (cpu->full_cpuid_auto_level) {
x86_cpu_adjust_feat_level(cpu, FEAT_1_EDX);
x86_cpu_adjust_feat_level(cpu, FEAT_1_ECX);
x86_cpu_adjust_feat_level(cpu, FEAT_6_EAX);
x86_cpu_adjust_feat_level(cpu, FEAT_7_0_ECX);
x86_cpu_adjust_feat_level(cpu, FEAT_8000_0001_EDX);
x86_cpu_adjust_feat_level(cpu, FEAT_8000_0001_ECX);
x86_cpu_adjust_feat_level(cpu, FEAT_8000_0007_EDX);
x86_cpu_adjust_feat_level(cpu, FEAT_C000_0001_EDX);
x86_cpu_adjust_feat_level(cpu, FEAT_SVM);
x86_cpu_adjust_feat_level(cpu, FEAT_XSAVE);
}

/* Set cpuid_*level* based on cpuid_min_*level, if not explicitly set */
if (env->cpuid_level == UINT32_MAX) {
env->cpuid_level = env->cpuid_min_level;
}
if (env->cpuid_xlevel == UINT32_MAX) {
env->cpuid_xlevel = env->cpuid_min_xlevel;
}
if (env->cpuid_xlevel2 == UINT32_MAX) {
env->cpuid_xlevel2 = env->cpuid_min_xlevel2;
}

if (x86_cpu_filter_features(cpu) && cpu->enforce_cpuid) {
Expand Down Expand Up @@ -3403,9 +3463,13 @@ static Property x86_cpu_properties[] = {
DEFINE_PROP_UINT32("phys-bits", X86CPU, phys_bits, 0),
DEFINE_PROP_BOOL("host-phys-bits", X86CPU, host_phys_bits, false),
DEFINE_PROP_BOOL("fill-mtrr-mask", X86CPU, fill_mtrr_mask, true),
DEFINE_PROP_UINT32("level", X86CPU, env.cpuid_level, 0),
DEFINE_PROP_UINT32("xlevel", X86CPU, env.cpuid_xlevel, 0),
DEFINE_PROP_UINT32("xlevel2", X86CPU, env.cpuid_xlevel2, 0),
DEFINE_PROP_UINT32("level", X86CPU, env.cpuid_level, UINT32_MAX),
DEFINE_PROP_UINT32("xlevel", X86CPU, env.cpuid_xlevel, UINT32_MAX),
DEFINE_PROP_UINT32("xlevel2", X86CPU, env.cpuid_xlevel2, UINT32_MAX),
DEFINE_PROP_UINT32("min-level", X86CPU, env.cpuid_min_level, 0),
DEFINE_PROP_UINT32("min-xlevel", X86CPU, env.cpuid_min_xlevel, 0),
DEFINE_PROP_UINT32("min-xlevel2", X86CPU, env.cpuid_min_xlevel2, 0),
DEFINE_PROP_BOOL("full-cpuid-auto-level", X86CPU, full_cpuid_auto_level, true),
DEFINE_PROP_STRING("hv-vendor-id", X86CPU, hyperv_vendor_id),
DEFINE_PROP_BOOL("cpuid-0xb", X86CPU, enable_cpuid_0xb, true),
DEFINE_PROP_BOOL("lmce", X86CPU, enable_lmce, false),
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12 changes: 9 additions & 3 deletions target-i386/cpu.h
View file
Expand Up @@ -1111,9 +1111,12 @@ typedef struct CPUX86State {
struct {} end_reset_fields;

/* processor features (e.g. for CPUID insn) */
uint32_t cpuid_level;
uint32_t cpuid_xlevel;
uint32_t cpuid_xlevel2;
/* Minimum level/xlevel/xlevel2, based on CPU model + features */
uint32_t cpuid_min_level, cpuid_min_xlevel, cpuid_min_xlevel2;
/* Maximum level/xlevel/xlevel2 value for auto-assignment: */
uint32_t cpuid_max_level, cpuid_max_xlevel, cpuid_max_xlevel2;
/* Actual level/xlevel/xlevel2 value: */
uint32_t cpuid_level, cpuid_xlevel, cpuid_xlevel2;
uint32_t cpuid_vendor1;
uint32_t cpuid_vendor2;
uint32_t cpuid_vendor3;
Expand Down Expand Up @@ -1218,6 +1221,9 @@ struct X86CPU {
/* Compatibility bits for old machine types: */
bool enable_cpuid_0xb;

/* Enable auto level-increase for all CPUID leaves */
bool full_cpuid_auto_level;

/* if true fill the top bits of the MTRR_PHYSMASKn variable range */
bool fill_mtrr_mask;

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45 changes: 45 additions & 0 deletions tests/test-x86-cpuid-compat.c
View file
Expand Up @@ -85,19 +85,64 @@ int main(int argc, char **argv)
"-cpu phenom", "xlevel", 0x8000001A);

/* If level is not large enough, it should increase automatically: */
/* CPUID[6].EAX: */
add_cpuid_test("x86/cpuid/auto-level/phenom/arat",
"-cpu 486,+arat", "level", 6);
/* CPUID[EAX=7,ECX=0].EBX: */
add_cpuid_test("x86/cpuid/auto-level/phenom/fsgsbase",
"-cpu phenom,+fsgsbase", "level", 7);
/* CPUID[EAX=7,ECX=0].ECX: */
add_cpuid_test("x86/cpuid/auto-level/phenom/avx512vbmi",
"-cpu phenom,+avx512vbmi", "level", 7);
/* CPUID[EAX=0xd,ECX=1].EAX: */
add_cpuid_test("x86/cpuid/auto-level/phenom/xsaveopt",
"-cpu phenom,+xsaveopt", "level", 0xd);
/* CPUID[8000_0001].EDX: */
add_cpuid_test("x86/cpuid/auto-xlevel/486/3dnow",
"-cpu 486,+3dnow", "xlevel", 0x80000001);
/* CPUID[8000_0001].ECX: */
add_cpuid_test("x86/cpuid/auto-xlevel/486/sse4a",
"-cpu 486,+sse4a", "xlevel", 0x80000001);
/* CPUID[8000_0007].EDX: */
add_cpuid_test("x86/cpuid/auto-xlevel/486/invtsc",
"-cpu 486,+invtsc", "xlevel", 0x80000007);
/* CPUID[8000_000A].EDX: */
add_cpuid_test("x86/cpuid/auto-xlevel/486/npt",
"-cpu 486,+npt", "xlevel", 0x8000000A);
/* CPUID[C000_0001].EDX: */
add_cpuid_test("x86/cpuid/auto-xlevel2/phenom/xstore",
"-cpu phenom,+xstore", "xlevel2", 0xC0000001);


/* If level is already large enough, it shouldn't change: */
add_cpuid_test("x86/cpuid/auto-level/SandyBridge/multiple",
"-cpu SandyBridge,+arat,+fsgsbase,+avx512vbmi",
"level", 0xd);
/* If level is explicitly set, it shouldn't change: */
add_cpuid_test("x86/cpuid/auto-level/486/fixed/0xF",
"-cpu 486,level=0xF,+arat,+fsgsbase,+avx512vbmi,+xsaveopt",
"level", 0xF);
add_cpuid_test("x86/cpuid/auto-level/486/fixed/2",
"-cpu 486,level=2,+arat,+fsgsbase,+avx512vbmi,+xsaveopt",
"level", 2);
add_cpuid_test("x86/cpuid/auto-level/486/fixed/0",
"-cpu 486,level=0,+arat,+fsgsbase,+avx512vbmi,+xsaveopt",
"level", 0);

/* if xlevel is already large enough, it shouldn't change: */
add_cpuid_test("x86/cpuid/auto-xlevel/phenom/3dnow",
"-cpu phenom,+3dnow,+sse4a,+invtsc,+npt",
"xlevel", 0x8000001A);
/* If xlevel is explicitly set, it shouldn't change: */
add_cpuid_test("x86/cpuid/auto-xlevel/486/fixed/80000002",
"-cpu 486,xlevel=0x80000002,+3dnow,+sse4a,+invtsc,+npt",
"xlevel", 0x80000002);
add_cpuid_test("x86/cpuid/auto-xlevel/486/fixed/8000001A",
"-cpu 486,xlevel=0x8000001A,+3dnow,+sse4a,+invtsc,+npt",
"xlevel", 0x8000001A);
add_cpuid_test("x86/cpuid/auto-xlevel/phenom/fixed/0",
"-cpu 486,xlevel=0,+3dnow,+sse4a,+invtsc,+npt",
"xlevel", 0);

/* if xlevel2 is already large enough, it shouldn't change: */
add_cpuid_test("x86/cpuid/auto-xlevel2/486/fixed",
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