From 880993138396f8f0be620c425d08f84490c35251 Mon Sep 17 00:00:00 2001 From: Maxim Levitsky Date: Tue, 22 Mar 2022 19:24:48 +0200 Subject: KVM: x86: SVM: fix tsc scaling when the host doesn't support it It was decided that when TSC scaling is not supported, the virtual MSR_AMD64_TSC_RATIO should still have the default '1.0' value. However in this case kvm_max_tsc_scaling_ratio is not set, which breaks various assumptions. Fix this by always calculating kvm_max_tsc_scaling_ratio regardless of host support. For consistency, do the same for VMX. Suggested-by: Paolo Bonzini Signed-off-by: Maxim Levitsky Message-Id: <20220322172449.235575-8-mlevitsk@redhat.com> Signed-off-by: Paolo Bonzini --- arch/x86/kvm/svm/svm.c | 4 ++-- arch/x86/kvm/vmx/vmx.c | 7 +++---- arch/x86/kvm/x86.c | 4 +--- 3 files changed, 6 insertions(+), 9 deletions(-) diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index cff941989431..bd4c64b362d2 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -4752,10 +4752,10 @@ static __init int svm_hardware_setup(void) } else { pr_info("TSC scaling supported\n"); kvm_has_tsc_control = true; - kvm_max_tsc_scaling_ratio = SVM_TSC_RATIO_MAX; - kvm_tsc_scaling_ratio_frac_bits = 32; } } + kvm_max_tsc_scaling_ratio = SVM_TSC_RATIO_MAX; + kvm_tsc_scaling_ratio_frac_bits = 32; tsc_aux_uret_slot = kvm_add_user_return_msr(MSR_TSC_AUX); diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index fb8d5b6d05f7..1bbd3e97694c 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -7980,12 +7980,11 @@ static __init int hardware_setup(void) if (!enable_apicv) vmx_x86_ops.sync_pir_to_irr = NULL; - if (cpu_has_vmx_tsc_scaling()) { + if (cpu_has_vmx_tsc_scaling()) kvm_has_tsc_control = true; - kvm_max_tsc_scaling_ratio = KVM_VMX_TSC_MULTIPLIER_MAX; - kvm_tsc_scaling_ratio_frac_bits = 48; - } + kvm_max_tsc_scaling_ratio = KVM_VMX_TSC_MULTIPLIER_MAX; + kvm_tsc_scaling_ratio_frac_bits = 48; kvm_has_bus_lock_exit = cpu_has_vmx_bus_lock_detection(); set_bit(0, vmx_vpid_bitmap); /* 0 is reserved for host */ diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index bc63ba52c4d6..498cd4aaa2cb 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -11602,10 +11602,8 @@ int kvm_arch_hardware_setup(void *opaque) u64 max = min(0x7fffffffULL, __scale_tsc(kvm_max_tsc_scaling_ratio, tsc_khz)); kvm_max_guest_tsc_khz = max; - - kvm_default_tsc_scaling_ratio = 1ULL << kvm_tsc_scaling_ratio_frac_bits; } - + kvm_default_tsc_scaling_ratio = 1ULL << kvm_tsc_scaling_ratio_frac_bits; kvm_init_msr_list(); return 0; } -- cgit v1.2.3