[PATCH v8 04/10] KVM: selftests: Add SMT control state helper

[Pratik R. Sampat]

Move the SMT control check out of the hyperv_cpuid selftest so that it
is generally accessible all KVM selftests. Split the functionality into
a helper that populates a buffer with SMT control value which other
helpers can use to ascertain if SMT state is available and active.

Signed-off-by: Pratik R. Sampat <prsam...@amd.com>
---
 .../testing/selftests/kvm/include/kvm_util.h  | 35 +++++++++++++++++++
 .../testing/selftests/kvm/x86/hyperv_cpuid.c  | 19 ----------
 2 files changed, 35 insertions(+), 19 deletions(-)

diff --git a/tools/testing/selftests/kvm/include/kvm_util.h 
b/tools/testing/selftests/kvm/include/kvm_util.h
index 4c4e5a847f67..446f04b2710f 100644
--- a/tools/testing/selftests/kvm/include/kvm_util.h
+++ b/tools/testing/selftests/kvm/include/kvm_util.h
@@ -542,6 +542,41 @@ static inline uint64_t vm_get_stat(struct kvm_vm *vm, 
const char *stat_name)
        return data;
 }
 
+static inline bool read_smt_control(char *buf, size_t buf_size)
+{
+       FILE *f = fopen("/sys/devices/system/cpu/smt/control", "r");
+       bool ret;
+
+       if (!f)
+               return false;
+
+       ret = fread(buf, sizeof(*buf), buf_size, f) > 0;
+       fclose(f);
+
+       return ret;
+}
+
+static inline bool smt_possible(void)
+{
+       char buf[16];
+
+       if (read_smt_control(buf, sizeof(buf)) &&
+           (!strncmp(buf, "forceoff", 8) || !strncmp(buf, "notsupported", 12)))
+               return false;
+
+       return true;
+}
+
+static inline bool smt_on(void)
+{
+       char buf[16];
+
+       if (read_smt_control(buf, sizeof(buf)) && !strncmp(buf, "on", 2))
+               return true;
+
+       return false;
+}
+
 void vm_create_irqchip(struct kvm_vm *vm);
 
 static inline int __vm_create_guest_memfd(struct kvm_vm *vm, uint64_t size,
diff --git a/tools/testing/selftests/kvm/x86/hyperv_cpuid.c 
b/tools/testing/selftests/kvm/x86/hyperv_cpuid.c
index 4e920705681a..1eb55d0b7297 100644
--- a/tools/testing/selftests/kvm/x86/hyperv_cpuid.c
+++ b/tools/testing/selftests/kvm/x86/hyperv_cpuid.c
@@ -22,25 +22,6 @@ static void guest_code(void)
 {
 }
 
-static bool smt_possible(void)
-{
-       char buf[16];
-       FILE *f;
-       bool res = true;
-
-       f = fopen("/sys/devices/system/cpu/smt/control", "r");
-       if (f) {
-               if (fread(buf, sizeof(*buf), sizeof(buf), f) > 0) {
-                       if (!strncmp(buf, "forceoff", 8) ||
-                           !strncmp(buf, "notsupported", 12))
-                               res = false;
-               }
-               fclose(f);
-       }
-
-       return res;
-}
-
 static void test_hv_cpuid(struct kvm_vcpu *vcpu, bool evmcs_expected)
 {
        const bool has_irqchip = !vcpu || vcpu->vm->has_irqchip;
-- 
2.43.0