From 99482726452bdf8be9325199022b17fa6d7d58fe Mon Sep 17 00:00:00 2001 From: Vitaly Kuznetsov Date: Tue, 12 Jul 2022 15:50:09 +0200 Subject: [PATCH] KVM: nVMX: Always enable TSC scaling for L2 when it was enabled for L1 Windows 10/11 guests with Hyper-V role (WSL2) enabled are observed to hang upon boot or shortly after when a non-default TSC frequency was set for L1. The issue is observed on a host where TSC scaling is supported. The problem appears to be that Windows doesn't use TSC frequency for its guests even when the feature is advertised and KVM filters SECONDARY_EXEC_TSC_SCALING out when creating L2 controls from L1's. This leads to L2 running with the default frequency (matching host's) while L1 is running with an altered one. Keep SECONDARY_EXEC_TSC_SCALING in secondary exec controls for L2 when it was set for L1. TSC_MULTIPLIER is already correctly computed and written by prepare_vmcs02(). Signed-off-by: Vitaly Kuznetsov Reviewed-by: Maxim Levitsky Message-Id: <20220712135009.952805-1-vkuznets@redhat.com> Signed-off-by: Paolo Bonzini --- arch/x86/kvm/vmx/nested.c | 1 - 1 file changed, 1 deletion(-) diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c index f5cb18e00e78..67d629837672 100644 --- a/arch/x86/kvm/vmx/nested.c +++ b/arch/x86/kvm/vmx/nested.c @@ -2278,7 +2278,6 @@ static void prepare_vmcs02_early(struct vcpu_vmx *vmx, struct loaded_vmcs *vmcs0 SECONDARY_EXEC_VIRTUAL_INTR_DELIVERY | SECONDARY_EXEC_APIC_REGISTER_VIRT | SECONDARY_EXEC_ENABLE_VMFUNC | - SECONDARY_EXEC_TSC_SCALING | SECONDARY_EXEC_DESC); if (nested_cpu_has(vmcs12,