target-i386/kvm: cache the return value of kvm_enable_x2apic()

Assume that KVM would have returned the same on subsequent runs.
Abstract the memoizaiton pattern into macros and call it memorize as
adding the r makes it less obscure.

Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
This commit is contained in:
Radim Krčmář 2016-10-10 17:28:48 +02:00 committed by Eduardo Habkost
parent fb506e701e
commit 2a138ec3af

View File

@ -129,10 +129,23 @@ static bool kvm_x2apic_api_set_flags(uint64_t flags)
return !kvm_vm_enable_cap(s, KVM_CAP_X2APIC_API, 0, flags);
}
#define MEMORIZE(fn) \
({ \
static typeof(fn) _result; \
static bool _memorized; \
\
if (_memorized) { \
return _result; \
} \
_memorized = true; \
_result = fn; \
})
bool kvm_enable_x2apic(void)
{
return kvm_x2apic_api_set_flags(KVM_X2APIC_API_USE_32BIT_IDS |
KVM_X2APIC_API_DISABLE_BROADCAST_QUIRK);
return MEMORIZE(
kvm_x2apic_api_set_flags(KVM_X2APIC_API_USE_32BIT_IDS |
KVM_X2APIC_API_DISABLE_BROADCAST_QUIRK));
}
static int kvm_get_tsc(CPUState *cs)