[0/2] i386: Adjust CPUID_EXT_PDCM based on enable_pmu at realization

Message

Xiaoyao Li March 4, 2025, 5:24 a.m. UTC

First, it's not a good practice that values in env->features[] cannot be
directly used for guest CPUID in void cpu_x86_cpuid(), but require further
adjustment there. env->features[] are supposed to be finalized at cpu
realization, so that after it env->features[] is reliable.

Second, there is one dependency entry relates to CPUID_EXT_PDCM in
feature_dependencies[]. QEMU needs to get correct value of
CPUID_EXT_PDCM in env->features[] to ensure applying the dependencies
correctly.

Patch 1 resolves above two points.

Patch 2 is a enhancement to give users a warning when they request pdcm
explicitly while PMU disabled.

Xiaoyao Li (2):
  i386/cpu: Move adjustment of CPUID_EXT_PDCM before
    feature_dependencies[] check
  i386/cpu: Warn about why CPUID_EXT_PDCM is not available

 target/i386/cpu.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)