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authorVitaly Kuznetsov <vkuznets@redhat.com>2019-09-16 18:22:56 +0200
committerPaolo Bonzini <pbonzini@redhat.com>2019-09-24 13:37:28 +0200
commite1572f1d08be57a5412a464cff0712a23cd0b73e (patch)
treed1ee6d7671cd371c765778c9a73777a823dfe848 /kernel
parenta073d7e3ad687a7ef32b65affe80faa7ce89bf92 (diff)
downloadlinux-e1572f1d08be57a5412a464cff0712a23cd0b73e.tar.gz
cpu/SMT: create and export cpu_smt_possible()
KVM needs to know if SMT is theoretically possible, this means it is supported and not forcefully disabled ('nosmt=force'). Create and export cpu_smt_possible() answering this question. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/cpu.c11
1 files changed, 9 insertions, 2 deletions
diff --git a/kernel/cpu.c b/kernel/cpu.c
index e1967e9eddc2..fc28e17940e0 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -392,8 +392,7 @@ enum cpuhp_smt_control cpu_smt_control __read_mostly = CPU_SMT_ENABLED;
void __init cpu_smt_disable(bool force)
{
- if (cpu_smt_control == CPU_SMT_FORCE_DISABLED ||
- cpu_smt_control == CPU_SMT_NOT_SUPPORTED)
+ if (!cpu_smt_possible())
return;
if (force) {
@@ -438,6 +437,14 @@ static inline bool cpu_smt_allowed(unsigned int cpu)
*/
return !cpumask_test_cpu(cpu, &cpus_booted_once_mask);
}
+
+/* Returns true if SMT is not supported of forcefully (irreversibly) disabled */
+bool cpu_smt_possible(void)
+{
+ return cpu_smt_control != CPU_SMT_FORCE_DISABLED &&
+ cpu_smt_control != CPU_SMT_NOT_SUPPORTED;
+}
+EXPORT_SYMBOL_GPL(cpu_smt_possible);
#else
static inline bool cpu_smt_allowed(unsigned int cpu) { return true; }
#endif