[Xen-devel] [PATCH] x86/vpmu_intel: Handle SMT consistently for programmable and fixed counters

[Mohit Gambhir <mohit.gambhir@xxxxxxxxxx>]

This patch masks .AnyThread bits in IA32_FIXED_CTR_CTRL MSR for all
versions of Intel Arhcitectural Performance Monitoring. Note that
.AnyThread bit (21) is already masked in IA32_PERFEVTSELx MSRs since
hyperthreading is not exposed to guests and Intel SDM discourages the use of
.AnyThread bit in virtualized environments (per section 18.2.3.1
AnyThread Counting and Software Evolution)

Signed-off-by: Mohit Gambhir <mohit.gambhir@xxxxxxxxxx>
---
 xen/arch/x86/cpu/vpmu_intel.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/xen/arch/x86/cpu/vpmu_intel.c b/xen/arch/x86/cpu/vpmu_intel.c
index 0d66ecb..7944e22 100644
--- a/xen/arch/x86/cpu/vpmu_intel.c
+++ b/xen/arch/x86/cpu/vpmu_intel.c
@@ -979,8 +979,7 @@ int __init core2_vpmu_init(void)
     full_width_write = (caps >> 13) & 1;
 
     fixed_ctrl_mask = ~((1ull << (fixed_pmc_cnt * FIXED_CTR_CTRL_BITS)) - 1);
-    if ( version == 2 )
-        fixed_ctrl_mask |= 0x444;
+    fixed_ctrl_mask |= 0x444;
     fixed_counters_mask = ~((1ull << core2_get_bitwidth_fix_count()) - 1);
     global_ctrl_mask = ~((((1ULL << fixed_pmc_cnt) - 1) << 32) |
                          ((1ULL << arch_pmc_cnt) - 1));
-- 
2.9.3


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