This patch implements the propagation of the VM virtual_tsc_khz into each vcpu data-structure to enable the tsc-scaling feature.
Signed-off-by: Joerg Roedel <[email protected]> --- arch/x86/kvm/svm.c | 33 +++++++++++++++++++++++++++++++++ 1 files changed, 33 insertions(+), 0 deletions(-) diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index b91547a..ae5ac88 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -888,6 +888,36 @@ static u64 svm_scale_tsc(struct kvm_vcpu *vcpu, u64 tsc) return _tsc; } +static bool svm_vcpu_init_tsc(struct kvm *kvm, struct vcpu_svm *svm) +{ + u64 ratio; + u64 khz; + + /* TSC scaling supported? */ + if (!boot_cpu_has(X86_FEATURE_TSCRATEMSR)) + return true; + + /* Guest tsc same frequency as host tsc? */ + if (kvm->arch.virtual_tsc_khz == tsc_khz) + return true; + + khz = kvm->arch.virtual_tsc_khz; + + if (khz == 0) + return false; + + /* TSC scaling required - calculate ratio */ + ratio = (u64)khz << 32; + do_div(ratio, tsc_khz); + if (ratio == 0 || ratio & TSC_RATIO_RSVD) + return false; + + svm->tsc_scale.ratio = ratio; + svm->tsc_scale.enabled = true; + + return true; +} + static void svm_write_tsc_offset(struct kvm_vcpu *vcpu, u64 offset) { struct vcpu_svm *svm = to_svm(vcpu); @@ -1093,6 +1123,9 @@ static struct kvm_vcpu *svm_create_vcpu(struct kvm *kvm, unsigned int id) if (err) goto free_svm; + if (!svm_vcpu_init_tsc(kvm, svm)) + goto uninit; + err = -ENOMEM; page = alloc_page(GFP_KERNEL); if (!page) -- 1.7.1 -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
