[Xen-devel] [PATCH v7 08/19] intel/VPMU: MSR_CORE_PERF_GLOBAL_CTRL should be initialized to zero

[Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx>]

MSR_CORE_PERF_GLOBAL_CTRL register should be set zero initially. It is up to
the guest to set it so that counters are enabled.

Signed-off-by: Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx>
Acked-by: Kevin Tian <kevin.tian@xxxxxxxxx>
Reviewed-by: Dietmar Hahn <dietmar.hahn@xxxxxxxxxxxxxx>
Tested-by: Dietmar Hahn <dietmar.hahn@xxxxxxxxxxxxxx>
---
 xen/arch/x86/hvm/vmx/vpmu_core2.c | 10 +---------
 1 file changed, 1 insertion(+), 9 deletions(-)

diff --git a/xen/arch/x86/hvm/vmx/vpmu_core2.c 
b/xen/arch/x86/hvm/vmx/vpmu_core2.c
index 94cfd6d..c7322f5 100644
--- a/xen/arch/x86/hvm/vmx/vpmu_core2.c
+++ b/xen/arch/x86/hvm/vmx/vpmu_core2.c
@@ -165,13 +165,6 @@ static int core2_get_fixed_pmc_count(void)
     return ( (eax & PMU_FIXED_NR_MASK) >> PMU_FIXED_NR_SHIFT );
 }
 
-static u64 core2_calc_intial_glb_ctrl_msr(void)
-{
-    int arch_pmc_bits = (1 << arch_pmc_cnt) - 1;
-    u64 fix_pmc_bits  = (1 << fixed_pmc_cnt) - 1;
-    return ( (fix_pmc_bits << 32) | arch_pmc_bits );
-}
-
 /* edx bits 5-12: Bit width of fixed-function performance counters  */
 static int core2_get_bitwidth_fix_count(void)
 {
@@ -375,8 +368,7 @@ static int core2_vpmu_alloc_resource(struct vcpu *v)
 
     if ( vmx_add_msr(MSR_CORE_PERF_GLOBAL_CTRL, VMX_GUEST_MSR) )
         goto out_err;
-    vmx_write_guest_msr(MSR_CORE_PERF_GLOBAL_CTRL,
-                 core2_calc_intial_glb_ctrl_msr());
+    vmx_write_guest_msr(MSR_CORE_PERF_GLOBAL_CTRL, 0);
 
     core2_vpmu_cxt = xzalloc_bytes(sizeof(struct core2_vpmu_context) +
                     (arch_pmc_cnt-1)*sizeof(struct arch_msr_pair));
-- 
1.8.1.4


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