On 17/02/17 15:05, Boris Ostrovsky wrote: > > > On 02/17/2017 02:36 AM, Juergen Gross wrote: >> When running as pv domain xen_cpuid() is being used instead of >> native_cpuid(). In xen_cpuid() the aperf/mperf feature is indicated >> as not being present by special casing the related cpuid leaf. >> >> Instead of delivering fake cpuid values clear the cpu capability bit >> for aperf/mperf instead. >> >> Signed-off-by: Juergen Gross <jgr...@suse.com> >> --- >> arch/x86/xen/enlighten.c | 11 +++-------- >> 1 file changed, 3 insertions(+), 8 deletions(-) >> >> diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c >> index 83399ce..0eebb75 100644 >> --- a/arch/x86/xen/enlighten.c >> +++ b/arch/x86/xen/enlighten.c >> @@ -301,9 +301,6 @@ xen_running_on_version_or_later(unsigned int >> major, unsigned int minor) >> return false; >> } >> >> -#define CPUID_THERM_POWER_LEAF 6 >> -#define APERFMPERF_PRESENT 0 >> - >> static __read_mostly unsigned int cpuid_leaf1_edx_mask = ~0; >> static __read_mostly unsigned int cpuid_leaf1_ecx_mask = ~0; >> >> @@ -337,11 +334,6 @@ static void xen_cpuid(unsigned int *ax, unsigned >> int *bx, >> *dx = cpuid_leaf5_edx_val; >> return; >> >> - case CPUID_THERM_POWER_LEAF: >> - /* Disabling APERFMPERF for kernel usage */ >> - maskecx = ~(1 << APERFMPERF_PRESENT); >> - break; >> - > > > But now APERF/MPERF will be reported as supported by CPUID, won't it?
Yes. But this shouldn't be a problem as the kernel is always testing X86_FEATURE_APERFMPERF for testing the support. >> case 0xb: >> /* Suppress extended topology stuff */ >> maskebx = 0; >> @@ -462,6 +454,9 @@ static void __init xen_init_cpuid_mask(void) >> if (xen_check_mwait()) >> cpuid_leaf1_ecx_set_mask = (1 << (X86_FEATURE_MWAIT % 32)); >> >> + /* Disable APERFMPERF feature. */ >> + setup_clear_cpu_cap(X86_FEATURE_APERFMPERF); >> + >> /* Disable DCA feature. */ >> setup_clear_cpu_cap(X86_FEATURE_DCA); > > > I think both of those can go to xen_set_cpu_features(). Okay. I'll move them. I think we can convert some of the remaining cpuid bit modifications to cpu capabilities as well. Juergen _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org https://lists.xen.org/xen-devel
