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target-i386: warns users when CPU threads>1 for non-Intel CPUs 

Only Intel CPUs support hyperthreading. When users select threads>1 in
-smp option, QEMU fixes it by adjusting CPUID_0000_0001_EBX and
CPUID_8000_0008_ECX based on inputs (sockets, cores, threads);
so guest VM can boot correctly. However it is still better to gives
users a warning when such case happens.

Signed-off-by: Wei Huang <wei@redhat.com>
[As suggested by Eduardo, check for !IS_INTEL instead of AMD. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Wei Huang 2014-10-21 11:00:45 -04:00 committed by Paolo Bonzini
parent b591721909
commit e48638fdb3
1 changed files with 23 additions and 3 deletions
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26
target-i386/cpu.c
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@ -2696,6 +2696,13 @@ static void x86_cpu_apic_realize(X86CPU *cpu, Error **errp)
} }
#endif #endif
#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)
#define IS_AMD_CPU(env) ((env)->cpuid_vendor1 == CPUID_VENDOR_AMD_1 && \
(env)->cpuid_vendor2 == CPUID_VENDOR_AMD_2 && \
(env)->cpuid_vendor3 == CPUID_VENDOR_AMD_3)
static void x86_cpu_realizefn(DeviceState *dev, Error **errp) static void x86_cpu_realizefn(DeviceState *dev, Error **errp)
{ {
CPUState *cs = CPU(dev); CPUState *cs = CPU(dev);
@ -2703,6 +2710,7 @@ static void x86_cpu_realizefn(DeviceState *dev, Error **errp)
X86CPUClass *xcc = X86_CPU_GET_CLASS(dev); X86CPUClass *xcc = X86_CPU_GET_CLASS(dev);
CPUX86State *env = &cpu->env; CPUX86State *env = &cpu->env;
Error *local_err = NULL; Error *local_err = NULL;
static bool ht_warned;
if (env->features[FEAT_7_0_EBX] && env->cpuid_level < 7) { if (env->features[FEAT_7_0_EBX] && env->cpuid_level < 7) {
env->cpuid_level = 7; env->cpuid_level = 7;
@ -2711,9 +2719,7 @@ static void x86_cpu_realizefn(DeviceState *dev, Error **errp)
/* On AMD CPUs, some CPUID[8000_0001].EDX bits must match the bits on /* On AMD CPUs, some CPUID[8000_0001].EDX bits must match the bits on
* CPUID[1].EDX. * CPUID[1].EDX.
*/ */
if (env->cpuid_vendor1 == CPUID_VENDOR_AMD_1 && if (IS_AMD_CPU(env)) {
env->cpuid_vendor2 == CPUID_VENDOR_AMD_2 &&
env->cpuid_vendor3 == CPUID_VENDOR_AMD_3) {
env->features[FEAT_8000_0001_EDX] &= ~CPUID_EXT2_AMD_ALIASES; env->features[FEAT_8000_0001_EDX] &= ~CPUID_EXT2_AMD_ALIASES;
env->features[FEAT_8000_0001_EDX] |= (env->features[FEAT_1_EDX] env->features[FEAT_8000_0001_EDX] |= (env->features[FEAT_1_EDX]
& CPUID_EXT2_AMD_ALIASES); & CPUID_EXT2_AMD_ALIASES);
@ -2742,6 +2748,20 @@ static void x86_cpu_realizefn(DeviceState *dev, Error **errp)
mce_init(cpu); mce_init(cpu);
qemu_init_vcpu(cs); qemu_init_vcpu(cs);
/* Only Intel CPUs support hyperthreading. Even though QEMU fixes this
* issue by adjusting CPUID_0000_0001_EBX and CPUID_8000_0008_ECX
* based on inputs (sockets,cores,threads), it is still better to gives
* users a warning.
*
* NOTE: the following code has to follow qemu_init_vcpu(). Otherwise
* cs->nr_threads hasn't be populated yet and the checking is incorrect.
*/
if (!IS_INTEL_CPU(env) && cs->nr_threads > 1 && !ht_warned) {
error_report("AMD CPU doesn't support hyperthreading. Please configure"
" -smp options properly.");
ht_warned = true;
}
x86_cpu_apic_realize(cpu, &local_err); x86_cpu_apic_realize(cpu, &local_err);
if (local_err != NULL) { if (local_err != NULL) {
goto out; goto out;