queue-5.1/kvm-x86-pmu-mask-the-result-of-rdpmc-according-to-th.patch

   1 From fd822f8bf0f622639f35cb923e0bac6e43684c5e 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/vmx/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 e39741997893..dd745b58ffd8 100644
  23 --- a/arch/x86/kvm/pmu.c
  24 +++ b/arch/x86/kvm/pmu.c
  25 @@ -283,7 +283,7 @@ int kvm_pmu_rdpmc(struct kvm_vcpu *vcpu, unsigned idx, u64 *data)
  26         bool fast_mode = idx & (1u << 31);
  27         struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
  28         struct kvm_pmc *pmc;
  29 -       u64 ctr_val;
  30 +       u64 mask = fast_mode ? ~0u : ~0ull;
  31
  32         if (!pmu->version)
  33                 return 1;
  34 @@ -291,15 +291,11 @@ int kvm_pmu_rdpmc(struct kvm_vcpu *vcpu, unsigned idx, u64 *data)
  35         if (is_vmware_backdoor_pmc(idx))
  36                 return kvm_pmu_rdpmc_vmware(vcpu, idx, data);
  37
  38 -       pmc = kvm_x86_ops->pmu_ops->msr_idx_to_pmc(vcpu, idx);
  39 +       pmc = kvm_x86_ops->pmu_ops->msr_idx_to_pmc(vcpu, idx, &mask);
  40         if (!pmc)
  41                 return 1;
  42
  43 -       ctr_val = pmc_read_counter(pmc);
  44 -       if (fast_mode)
  45 -               ctr_val = (u32)ctr_val;
  46 -
  47 -       *data = ctr_val;
  48 +       *data = pmc_read_counter(pmc) & mask;
  49         return 0;
  50  }
  51
  52 diff --git a/arch/x86/kvm/pmu.h b/arch/x86/kvm/pmu.h
  53 index ba8898e1a854..22dff661145a 100644
  54 --- a/arch/x86/kvm/pmu.h
  55 +++ b/arch/x86/kvm/pmu.h
  56 @@ -25,7 +25,8 @@ struct kvm_pmu_ops {
  57         unsigned (*find_fixed_event)(int idx);
  58         bool (*pmc_is_enabled)(struct kvm_pmc *pmc);
  59         struct kvm_pmc *(*pmc_idx_to_pmc)(struct kvm_pmu *pmu, int pmc_idx);
  60 -       struct kvm_pmc *(*msr_idx_to_pmc)(struct kvm_vcpu *vcpu, unsigned idx);
  61 +       struct kvm_pmc *(*msr_idx_to_pmc)(struct kvm_vcpu *vcpu, unsigned idx,
  62 +                                         u64 *mask);
  63         int (*is_valid_msr_idx)(struct kvm_vcpu *vcpu, unsigned idx);
  64         bool (*is_valid_msr)(struct kvm_vcpu *vcpu, u32 msr);
  65         int (*get_msr)(struct kvm_vcpu *vcpu, u32 msr, u64 *data);
  66 diff --git a/arch/x86/kvm/pmu_amd.c b/arch/x86/kvm/pmu_amd.c
  67 index 50fa9450fcf1..d3118088f1cd 100644
  68 --- a/arch/x86/kvm/pmu_amd.c
  69 +++ b/arch/x86/kvm/pmu_amd.c
  70 @@ -186,7 +186,7 @@ static int amd_is_valid_msr_idx(struct kvm_vcpu *vcpu, unsigned idx)
  71  }
  72
  73  /* idx is the ECX register of RDPMC instruction */
  74 -static struct kvm_pmc *amd_msr_idx_to_pmc(struct kvm_vcpu *vcpu, unsigned idx)
  75 +static struct kvm_pmc *amd_msr_idx_to_pmc(struct kvm_vcpu *vcpu, unsigned idx, u64 *mask)
  76  {
  77         struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
  78         struct kvm_pmc *counters;
  79 diff --git a/arch/x86/kvm/vmx/pmu_intel.c b/arch/x86/kvm/vmx/pmu_intel.c
  80 index 5ab4a364348e..ad7ea81fbfbf 100644
  81 --- a/arch/x86/kvm/vmx/pmu_intel.c
  82 +++ b/arch/x86/kvm/vmx/pmu_intel.c
  83 @@ -126,7 +126,7 @@ static int intel_is_valid_msr_idx(struct kvm_vcpu *vcpu, unsigned idx)
  84  }
  85
  86  static struct kvm_pmc *intel_msr_idx_to_pmc(struct kvm_vcpu *vcpu,
  87 -                                           unsigned idx)
  88 +                                           unsigned idx, u64 *mask)
  89  {
  90         struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
  91         bool fixed = idx & (1u << 30);
  92 @@ -138,6 +138,7 @@ static struct kvm_pmc *intel_msr_idx_to_pmc(struct kvm_vcpu *vcpu,
  93         if (fixed && idx >= pmu->nr_arch_fixed_counters)
  94                 return NULL;
  95         counters = fixed ? pmu->fixed_counters : pmu->gp_counters;
  96 +       *mask &= pmu->counter_bitmask[fixed ? KVM_PMC_FIXED : KVM_PMC_GP];
  97
  98         return &counters[idx];
  99  }
 100 @@ -183,9 +184,13 @@ static int intel_pmu_get_msr(struct kvm_vcpu *vcpu, u32 msr, u64 *data)
 101                 *data = pmu->global_ovf_ctrl;
 102                 return 0;
 103         default:
 104 -               if ((pmc = get_gp_pmc(pmu, msr, MSR_IA32_PERFCTR0)) ||
 105 -                   (pmc = get_fixed_pmc(pmu, msr))) {
 106 -                       *data = pmc_read_counter(pmc);
 107 +               if ((pmc = get_gp_pmc(pmu, msr, MSR_IA32_PERFCTR0))) {
 108 +                       u64 val = pmc_read_counter(pmc);
 109 +                       *data = val & pmu->counter_bitmask[KVM_PMC_GP];
 110 +                       return 0;
 111 +               } else if ((pmc = get_fixed_pmc(pmu, msr))) {
 112 +                       u64 val = pmc_read_counter(pmc);
 113 +                       *data = val & pmu->counter_bitmask[KVM_PMC_FIXED];
 114                         return 0;
 115                 } else if ((pmc = get_gp_pmc(pmu, msr, MSR_P6_EVNTSEL0))) {
 116                         *data = pmc->eventsel;
 117 --
 118 2.20.1
 119