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| author | Sean Christopherson <seanjc@google.com> | 2023-05-12 02:33:46 +0300 |
|---|---|---|
| committer | Sean Christopherson <seanjc@google.com> | 2023-06-01 23:41:06 +0300 |
| commit | ebda79e5057778be1ad8ed072e4229894dfc66b7 (patch) | |
| tree | 7b17196e7431649e7beeadd849a94f92bc2426f4 /arch/x86/kvm/mtrr.c | |
| parent | 7aeae027611ff27f13a32e19736c8fd06e41786c (diff) | |
| download | linux-ebda79e5057778be1ad8ed072e4229894dfc66b7.tar.xz | |
KVM: x86: Add helper to query if variable MTRR MSR is base (versus mask)
Add a helper to query whether a variable MTRR MSR is a base versus as mask
MSR. Replace the unnecessarily complex math with a simple check on bit 0;
base MSRs are even, mask MSRs are odd.
Link: https://lore.kernel.org/r/20230511233351.635053-4-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Diffstat (limited to 'arch/x86/kvm/mtrr.c')
| -rw-r--r-- | arch/x86/kvm/mtrr.c | 16 |
1 files changed, 9 insertions, 7 deletions
diff --git a/arch/x86/kvm/mtrr.c b/arch/x86/kvm/mtrr.c index 9fac1ec03463..f65ce4b3980f 100644 --- a/arch/x86/kvm/mtrr.c +++ b/arch/x86/kvm/mtrr.c @@ -25,6 +25,12 @@ #define IA32_MTRR_DEF_TYPE_FE (1ULL << 10) #define IA32_MTRR_DEF_TYPE_TYPE_MASK (0xff) +static bool is_mtrr_base_msr(unsigned int msr) +{ + /* MTRR base MSRs use even numbers, masks use odd numbers. */ + return !(msr & 0x1); +} + static bool msr_mtrr_valid(unsigned msr) { switch (msr) { @@ -342,10 +348,9 @@ static void set_var_mtrr_msr(struct kvm_vcpu *vcpu, u32 msr, u64 data) { struct kvm_mtrr *mtrr_state = &vcpu->arch.mtrr_state; struct kvm_mtrr_range *tmp, *cur; - int index, is_mtrr_mask; + int index; index = (msr - 0x200) / 2; - is_mtrr_mask = msr - 0x200 - 2 * index; cur = &mtrr_state->var_ranges[index]; /* remove the entry if it's in the list. */ @@ -356,7 +361,7 @@ static void set_var_mtrr_msr(struct kvm_vcpu *vcpu, u32 msr, u64 data) * Set all illegal GPA bits in the mask, since those bits must * implicitly be 0. The bits are then cleared when reading them. */ - if (!is_mtrr_mask) + if (is_mtrr_base_msr(msr)) cur->base = data; else cur->mask = data | kvm_vcpu_reserved_gpa_bits_raw(vcpu); @@ -418,11 +423,8 @@ int kvm_mtrr_get_msr(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata) else if (msr == MSR_IA32_CR_PAT) *pdata = vcpu->arch.pat; else { /* Variable MTRRs */ - int is_mtrr_mask; - index = (msr - 0x200) / 2; - is_mtrr_mask = msr - 0x200 - 2 * index; - if (!is_mtrr_mask) + if (is_mtrr_base_msr(msr)) *pdata = vcpu->arch.mtrr_state.var_ranges[index].base; else *pdata = vcpu->arch.mtrr_state.var_ranges[index].mask; |