pending-4.19/kvm-x86-pmu-mask-the-result-of-rdpmc-according-to-th.patch

   1 From be536c2e23dc305f7ac01a9474b170bafa6ed761 Mon Sep 17 00:00:00 2001
   2 From: Paolo Bonzini <pbonzini@redhat.com>
   3 Date: Mon, 20 May 2019 17:20:40 +0200
   4 Subject: KVM: x86/pmu: mask the result of rdpmc according to the width of the
   5  counters
   6
   7 [ Upstream commit 0e6f467ee28ec97f68c7b74e35ec1601bb1368a7 ]
   8
   9 This patch will simplify the changes in the next, by enforcing the
  10 masking of the counters to RDPMC and RDMSR.
  11
  12 Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
  13 Signed-off-by: Sasha Levin <sashal@kernel.org>
  14 ---
  15  arch/x86/kvm/pmu.c       | 10 +++-------
  16  arch/x86/kvm/pmu.h       |  3 ++-
  17  arch/x86/kvm/pmu_amd.c   |  2 +-
  18  arch/x86/kvm/pmu_intel.c | 13 +++++++++----
  19  4 files changed, 15 insertions(+), 13 deletions(-)
  20
  21 diff --git a/arch/x86/kvm/pmu.c b/arch/x86/kvm/pmu.c
  22 index 58ead7db71a3..952aebd0a8a3 100644
  23 --- a/arch/x86/kvm/pmu.c
  24 +++ b/arch/x86/kvm/pmu.c
  25 @@ -282,20 +282,16 @@ int kvm_pmu_rdpmc(struct kvm_vcpu *vcpu, unsigned idx, u64 *data)
  26  {
  27         bool fast_mode = idx & (1u << 31);
  28         struct kvm_pmc *pmc;
  29 -       u64 ctr_val;
  30 +       u64 mask = fast_mode ? ~0u : ~0ull;
  31
  32         if (is_vmware_backdoor_pmc(idx))
  33                 return kvm_pmu_rdpmc_vmware(vcpu, idx, data);
  34
  35 -       pmc = kvm_x86_ops->pmu_ops->msr_idx_to_pmc(vcpu, idx);
  36 +       pmc = kvm_x86_ops->pmu_ops->msr_idx_to_pmc(vcpu, idx, &mask);
  37         if (!pmc)
  38                 return 1;
  39
  40 -       ctr_val = pmc_read_counter(pmc);
  41 -       if (fast_mode)
  42 -               ctr_val = (u32)ctr_val;
  43 -
  44 -       *data = ctr_val;
  45 +       *data = pmc_read_counter(pmc) & mask;
  46         return 0;
  47  }
  48
  49 diff --git a/arch/x86/kvm/pmu.h b/arch/x86/kvm/pmu.h
  50 index ba8898e1a854..22dff661145a 100644
  51 --- a/arch/x86/kvm/pmu.h
  52 +++ b/arch/x86/kvm/pmu.h
  53 @@ -25,7 +25,8 @@ struct kvm_pmu_ops {
  54         unsigned (*find_fixed_event)(int idx);
  55         bool (*pmc_is_enabled)(struct kvm_pmc *pmc);
  56         struct kvm_pmc *(*pmc_idx_to_pmc)(struct kvm_pmu *pmu, int pmc_idx);
  57 -       struct kvm_pmc *(*msr_idx_to_pmc)(struct kvm_vcpu *vcpu, unsigned idx);
  58 +       struct kvm_pmc *(*msr_idx_to_pmc)(struct kvm_vcpu *vcpu, unsigned idx,
  59 +                                         u64 *mask);
  60         int (*is_valid_msr_idx)(struct kvm_vcpu *vcpu, unsigned idx);
  61         bool (*is_valid_msr)(struct kvm_vcpu *vcpu, u32 msr);
  62         int (*get_msr)(struct kvm_vcpu *vcpu, u32 msr, u64 *data);
  63 diff --git a/arch/x86/kvm/pmu_amd.c b/arch/x86/kvm/pmu_amd.c
  64 index 1495a735b38e..41dff881e0f0 100644
  65 --- a/arch/x86/kvm/pmu_amd.c
  66 +++ b/arch/x86/kvm/pmu_amd.c
  67 @@ -186,7 +186,7 @@ static int amd_is_valid_msr_idx(struct kvm_vcpu *vcpu, unsigned idx)
  68  }
  69
  70  /* idx is the ECX register of RDPMC instruction */
  71 -static struct kvm_pmc *amd_msr_idx_to_pmc(struct kvm_vcpu *vcpu, unsigned idx)
  72 +static struct kvm_pmc *amd_msr_idx_to_pmc(struct kvm_vcpu *vcpu, unsigned idx, u64 *mask)
  73  {
  74         struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
  75         struct kvm_pmc *counters;
  76 diff --git a/arch/x86/kvm/pmu_intel.c b/arch/x86/kvm/pmu_intel.c
  77 index 5ab4a364348e..ad7ea81fbfbf 100644
  78 --- a/arch/x86/kvm/pmu_intel.c
  79 +++ b/arch/x86/kvm/pmu_intel.c
  80 @@ -126,7 +126,7 @@ static int intel_is_valid_msr_idx(struct kvm_vcpu *vcpu, unsigned idx)
  81  }
  82
  83  static struct kvm_pmc *intel_msr_idx_to_pmc(struct kvm_vcpu *vcpu,
  84 -                                           unsigned idx)
  85 +                                           unsigned idx, u64 *mask)
  86  {
  87         struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
  88         bool fixed = idx & (1u << 30);
  89 @@ -138,6 +138,7 @@ static struct kvm_pmc *intel_msr_idx_to_pmc(struct kvm_vcpu *vcpu,
  90         if (fixed && idx >= pmu->nr_arch_fixed_counters)
  91                 return NULL;
  92         counters = fixed ? pmu->fixed_counters : pmu->gp_counters;
  93 +       *mask &= pmu->counter_bitmask[fixed ? KVM_PMC_FIXED : KVM_PMC_GP];
  94
  95         return &counters[idx];
  96  }
  97 @@ -183,9 +184,13 @@ static int intel_pmu_get_msr(struct kvm_vcpu *vcpu, u32 msr, u64 *data)
  98                 *data = pmu->global_ovf_ctrl;
  99                 return 0;
 100         default:
 101 -               if ((pmc = get_gp_pmc(pmu, msr, MSR_IA32_PERFCTR0)) ||
 102 -                   (pmc = get_fixed_pmc(pmu, msr))) {
 103 -                       *data = pmc_read_counter(pmc);
 104 +               if ((pmc = get_gp_pmc(pmu, msr, MSR_IA32_PERFCTR0))) {
 105 +                       u64 val = pmc_read_counter(pmc);
 106 +                       *data = val & pmu->counter_bitmask[KVM_PMC_GP];
 107 +                       return 0;
 108 +               } else if ((pmc = get_fixed_pmc(pmu, msr))) {
 109 +                       u64 val = pmc_read_counter(pmc);
 110 +                       *data = val & pmu->counter_bitmask[KVM_PMC_FIXED];
 111                         return 0;
 112                 } else if ((pmc = get_gp_pmc(pmu, msr, MSR_P6_EVNTSEL0))) {
 113                         *data = pmc->eventsel;
 114 --
 115 2.20.1
 116