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| author | Ilias Stamatis <ilstam@amazon.com> | 2021-06-07 11:54:38 +0100 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2021-06-17 13:09:29 -0400 |
| commit | 1ab9287add5e265352d18517551abf6d01d004fd (patch) | |
| tree | 2c1b577ef4028b808d71184e7cb9ddd21859babe /arch/x86/kvm/svm/svm.c | |
| parent | edcfe54058114cb3782cd2e919c224e14420e76e (diff) | |
| download | lwn-1ab9287add5e265352d18517551abf6d01d004fd.tar.gz lwn-1ab9287add5e265352d18517551abf6d01d004fd.zip | |
KVM: X86: Add vendor callbacks for writing the TSC multiplier
Currently vmx_vcpu_load_vmcs() writes the TSC_MULTIPLIER field of the
VMCS every time the VMCS is loaded. Instead of doing this, set this
field from common code on initialization and whenever the scaling ratio
changes.
Additionally remove vmx->current_tsc_ratio. This field is redundant as
vcpu->arch.tsc_scaling_ratio already tracks the current TSC scaling
ratio. The vmx->current_tsc_ratio field is only used for avoiding
unnecessary writes but it is no longer needed after removing the code
from the VMCS load path.
Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Ilias Stamatis <ilstam@amazon.com>
Message-Id: <20210607105438.16541-1-ilstam@amazon.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kvm/svm/svm.c')
| -rw-r--r-- | arch/x86/kvm/svm/svm.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index 623f3c4b795a..a4d29ee9422d 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -1101,6 +1101,11 @@ static void svm_write_tsc_offset(struct kvm_vcpu *vcpu, u64 offset) vmcb_mark_dirty(svm->vmcb, VMCB_INTERCEPTS); } +static void svm_write_tsc_multiplier(struct kvm_vcpu *vcpu, u64 multiplier) +{ + wrmsrl(MSR_AMD64_TSC_RATIO, multiplier); +} + /* Evaluate instruction intercepts that depend on guest CPUID features. */ static void svm_recalc_instruction_intercepts(struct kvm_vcpu *vcpu, struct vcpu_svm *svm) @@ -4526,6 +4531,7 @@ static struct kvm_x86_ops svm_x86_ops __initdata = { .get_l2_tsc_offset = svm_get_l2_tsc_offset, .get_l2_tsc_multiplier = svm_get_l2_tsc_multiplier, .write_tsc_offset = svm_write_tsc_offset, + .write_tsc_multiplier = svm_write_tsc_multiplier, .load_mmu_pgd = svm_load_mmu_pgd, |