[v2] kvm/i386: fix return values of is_host_cpu_intel()

Commit Message

Ani Sinha Sept. 3, 2024, 8 a.m. UTC

is_host_cpu_intel() should return TRUE if the host cpu in Intel based, otherwise
it should return FALSE. Currently, it returns zero (FALSE) when the host CPU
is INTEL and non-zero otherwise. Fix the function so that it agrees more with
the semantics. Adjust the calling logic accordingly. RAPL needs Intel host cpus.
If the host CPU is not Intel baseed, we should report error.

Signed-off-by: Ani Sinha <[e-mail]>
---
 target/i386/kvm/kvm.c         | 2 +-
 target/i386/kvm/vmsr_energy.c | 4 ++--
 target/i386/kvm/vmsr_energy.h | 2 +-
 3 files changed, 4 insertions(+), 4 deletions(-)
 
changelog:
v2: fix comparison logic in is_host_cpu_intel so that it returns
boolean TRUE for Intel host CPU and false otherwise.

Comments

Paolo Bonzini Sept. 4, 2024, 12:19 p.m. UTC | #1

Queued, thanks (reverting the bool->gboolean change; QEMU does not use
g* types and they are kinda deprecated in glib too).

Paolo

Patch

diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c
index 11c7619bfd..503e8d956e 100644
--- a/target/i386/kvm/kvm.c
+++ b/target/i386/kvm/kvm.c
@@ -2898,7 +2898,7 @@  static int kvm_msr_energy_thread_init(KVMState *s, MachineState *ms)
      * 1. Host cpu must be Intel cpu
      * 2. RAPL must be enabled on the Host
      */
-    if (is_host_cpu_intel()) {
+    if (!is_host_cpu_intel()) {
         error_report("The RAPL feature can only be enabled on hosts\
                       with Intel CPU models");
         ret = 1;
diff --git a/target/i386/kvm/vmsr_energy.c b/target/i386/kvm/vmsr_energy.c
index 7e064c5aef..ce7eecb02d 100644
--- a/target/i386/kvm/vmsr_energy.c
+++ b/target/i386/kvm/vmsr_energy.c
@@ -27,14 +27,14 @@  char *vmsr_compute_default_paths(void)
     return g_build_filename(state, "run", "qemu-vmsr-helper.sock", NULL);
 }
 
-bool is_host_cpu_intel(void)
+gboolean is_host_cpu_intel(void)
 {
     int family, model, stepping;
     char vendor[CPUID_VENDOR_SZ + 1];
 
     host_cpu_vendor_fms(vendor, &family, &model, &stepping);
 
-    return strcmp(vendor, CPUID_VENDOR_INTEL);
+    return g_str_equal(vendor, CPUID_VENDOR_INTEL);
 }
 
 int is_rapl_enabled(void)
diff --git a/target/i386/kvm/vmsr_energy.h b/target/i386/kvm/vmsr_energy.h
index 16cc1f4814..97045986b7 100644
--- a/target/i386/kvm/vmsr_energy.h
+++ b/target/i386/kvm/vmsr_energy.h
@@ -94,6 +94,6 @@  double vmsr_get_ratio(uint64_t e_delta,
                       unsigned long long delta_ticks,
                       unsigned int maxticks);
 void vmsr_init_topo_info(X86CPUTopoInfo *topo_info, const MachineState *ms);
-bool is_host_cpu_intel(void);
+gboolean is_host_cpu_intel(void);
 int is_rapl_enabled(void);
 #endif /* VMSR_ENERGY_H */