The CPUID level need to be set to 0x14 manually on old
machine-type if Intel PT is enabled in guest. e.g. in Qemu 3.1
-machine pc-i440fx-3.1 -cpu qemu64,+intel-pt
will be CPUID[0].EAX(level)=7 and CPUID[7].EBX[25](intel-pt)=1.
Some Intel PT capabilities are exposed by leaf 0x14 and the
missing capabilities will cause some MSRs access failed.
This patch add a warning message to inform the user to extend
the CPUID level.
Suggested-by: Eduardo Habkost <ehabk...@redhat.com>
Signed-off-by: Luwei Kang <luwei.k...@intel.com>
---
target/i386/cpu.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/target/i386/cpu.c b/target/i386/cpu.c
index 47200b4..9abbd30 100644
--- a/target/i386/cpu.c
+++ b/target/i386/cpu.c
@@ -5393,8 +5393,12 @@ static void x86_cpu_expand_features(X86CPU *cpu, Error
**errp)
/* Intel Processor Trace requires CPUID[0x14] */
if ((env->features[FEAT_7_0_EBX] & CPUID_7_0_EBX_INTEL_PT) &&
- kvm_enabled() && cpu->intel_pt_auto_level) {
- x86_cpu_adjust_level(cpu, &cpu->env.cpuid_min_level, 0x14);
+ kvm_enabled()) {
+ if (cpu->intel_pt_auto_level)
+ x86_cpu_adjust_level(cpu, &cpu->env.cpuid_min_level, 0x14);
+ else
+ warn_report("Intel PT need CPUID leaf 0x14, please set "
+ "by \"-cpu ...,+intel-pt,level=0x14\"\n");
}
/* CPU topology with multi-dies support requires CPUID[0x1F] */
--
1.8.3.1
