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Subject[PATCH v2 03/11] x86/xen: use capabilities instead of fake cpuid values for aperf
Date
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 <jgross@suse.com>
---
arch/x86/xen/enlighten_pv.c | 9 +--------
1 file changed, 1 insertion(+), 8 deletions(-)

diff --git a/arch/x86/xen/enlighten_pv.c b/arch/x86/xen/enlighten_pv.c
index bd69868909b4..4c8cd7278189 100644
--- a/arch/x86/xen/enlighten_pv.c
+++ b/arch/x86/xen/enlighten_pv.c
@@ -165,9 +165,6 @@ 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;

@@ -201,11 +198,6 @@ 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;
-
case 0xb:
/* Suppress extended topology stuff */
maskebx = 0;
@@ -332,6 +324,7 @@ static void __init xen_init_capabilities(void)
setup_clear_cpu_cap(X86_BUG_SYSRET_SS_ATTRS);
setup_force_cpu_cap(X86_FEATURE_XENPV);
setup_clear_cpu_cap(X86_FEATURE_DCA);
+ setup_clear_cpu_cap(X86_FEATURE_APERFMPERF);
}

static void xen_set_debugreg(int reg, unsigned long val)
--
2.12.0
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