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| author | Sean Christopherson <[email protected]> | 2023-07-29 01:15:52 +0000 |
|---|---|---|
| committer | Sean Christopherson <[email protected]> | 2023-08-04 00:16:29 +0000 |
| commit | 2d63699099ac1fad13a0dbf8538faf4127c062e8 (patch) | |
| tree | f42d430a578d4dbe37d48b75c4a5647ec6cbfe99 /arch/x86/kvm/svm/nested.c | |
| parent | KVM: SVM: Clean up preemption toggling related to MSR_AMD64_TSC_RATIO (diff) | |
| download | kernel-2d63699099ac1fad13a0dbf8538faf4127c062e8.tar.gz kernel-2d63699099ac1fad13a0dbf8538faf4127c062e8.zip | |
KVM: x86: Always write vCPU's current TSC offset/ratio in vendor hooks
Drop the @offset and @multiplier params from the kvm_x86_ops hooks for
propagating TSC offsets/multipliers into hardware, and instead have the
vendor implementations pull the information directly from the vCPU
structure. The respective vCPU fields _must_ be written at the same
time in order to maintain consistent state, i.e. it's not random luck
that the value passed in by all callers is grabbed from the vCPU.
Explicitly grabbing the value from the vCPU field in SVM's implementation
in particular will allow for additional cleanup without introducing even
more subtle dependencies. Specifically, SVM can skip the WRMSR if guest
state isn't loaded, i.e. svm_prepare_switch_to_guest() will load the
correct value for the vCPU prior to entering the guest.
This also reconciles KVM's handling of related values that are stored in
the vCPU, as svm_write_tsc_offset() already assumes/requires the caller
to have updated l1_tsc_offset.
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Sean Christopherson <[email protected]>
Diffstat (limited to 'arch/x86/kvm/svm/nested.c')
| -rw-r--r-- | arch/x86/kvm/svm/nested.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c index 5d5a1d7832fb..3342cc4a5189 100644 --- a/arch/x86/kvm/svm/nested.c +++ b/arch/x86/kvm/svm/nested.c @@ -1103,7 +1103,7 @@ int nested_svm_vmexit(struct vcpu_svm *svm) if (kvm_caps.has_tsc_control && vcpu->arch.tsc_scaling_ratio != vcpu->arch.l1_tsc_scaling_ratio) { vcpu->arch.tsc_scaling_ratio = vcpu->arch.l1_tsc_scaling_ratio; - svm_write_tsc_multiplier(vcpu, vcpu->arch.tsc_scaling_ratio); + svm_write_tsc_multiplier(vcpu); } svm->nested.ctl.nested_cr3 = 0; @@ -1536,7 +1536,7 @@ void nested_svm_update_tsc_ratio_msr(struct kvm_vcpu *vcpu) vcpu->arch.tsc_scaling_ratio = kvm_calc_nested_tsc_multiplier(vcpu->arch.l1_tsc_scaling_ratio, svm->tsc_ratio_msr); - svm_write_tsc_multiplier(vcpu, vcpu->arch.tsc_scaling_ratio); + svm_write_tsc_multiplier(vcpu); } /* Inverse operation of nested_copy_vmcb_control_to_cache(). asid is copied too. */ |