diff options
| -rw-r--r-- | hw/i386/pc.c | 1 | ||||
| -rw-r--r-- | target/i386/cpu.c | 15 | ||||
| -rw-r--r-- | target/i386/cpu.h | 6 |
3 files changed, 19 insertions, 3 deletions
diff --git a/hw/i386/pc.c b/hw/i386/pc.c index d7f4815..4668918 100644 --- a/hw/i386/pc.c +++ b/hw/i386/pc.c @@ -88,6 +88,7 @@ GlobalProperty pc_compat_10_0[] = { { TYPE_X86_CPU, "x-consistent-cache", "false" }, { TYPE_X86_CPU, "x-vendor-cpuid-only-v2", "false" }, { TYPE_X86_CPU, "x-arch-cap-always-on", "true" }, + { TYPE_X86_CPU, "x-pdcm-on-even-without-pmu", "true" }, }; const size_t pc_compat_10_0_len = G_N_ELEMENTS(pc_compat_10_0); diff --git a/target/i386/cpu.c b/target/i386/cpu.c index fe369bb..ab18de8 100644 --- a/target/i386/cpu.c +++ b/target/i386/cpu.c @@ -7908,6 +7908,11 @@ void cpu_x86_cpuid(CPUX86State *env, uint32_t index, uint32_t count, /* Fixup overflow: max value for bits 23-16 is 255. */ *ebx |= MIN(num, 255) << 16; } + if (cpu->pdcm_on_even_without_pmu) { + if (!cpu->enable_pmu) { + *ecx &= ~CPUID_EXT_PDCM; + } + } break; case 2: { /* cache info: needed for Pentium Pro compatibility */ const CPUCaches *caches; @@ -8958,9 +8963,11 @@ void x86_cpu_expand_features(X86CPU *cpu, Error **errp) } } - /* PDCM is fixed1 bit for TDX */ - if (!cpu->enable_pmu && !is_tdx_vm()) { - env->features[FEAT_1_ECX] &= ~CPUID_EXT_PDCM; + if (!cpu->pdcm_on_even_without_pmu) { + /* PDCM is fixed1 bit for TDX */ + if (!cpu->enable_pmu && !is_tdx_vm()) { + env->features[FEAT_1_ECX] &= ~CPUID_EXT_PDCM; + } } for (i = 0; i < ARRAY_SIZE(feature_dependencies); i++) { @@ -10021,6 +10028,8 @@ static const Property x86_cpu_properties[] = { DEFINE_PROP_BOOL("x-arch-cap-always-on", X86CPU, arch_cap_always_on, false), + DEFINE_PROP_BOOL("x-pdcm-on-even-without-pmu", X86CPU, + pdcm_on_even_without_pmu, false), }; #ifndef CONFIG_USER_ONLY diff --git a/target/i386/cpu.h b/target/i386/cpu.h index 414ca96..42168f1 100644 --- a/target/i386/cpu.h +++ b/target/i386/cpu.h @@ -2320,6 +2320,12 @@ struct ArchCPU { */ bool arch_cap_always_on; + /* + * Backwards compatibility with QEMU <10.1. The PDCM feature is now disabled when + * PMU is not available, but prior to 10.1 it was enabled even if PMU is off. + */ + bool pdcm_on_even_without_pmu; + /* Number of physical address bits supported */ uint32_t phys_bits; |