The patch below does not apply to the 5.19-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 156b9d76e8822f2956c15029acf2d4b171502f3a Mon Sep 17 00:00:00 2001 From: Vitaly Kuznetsov vkuznets@redhat.com 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 scaling for its guests, even when the feature is advertised, and KVM filters SECONDARY_EXEC_TSC_SCALING out when creating L2 controls from L1's VMCS. 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 vkuznets@redhat.com Fixes: d041b5ea93352b ("KVM: nVMX: Enable nested TSC scaling") Cc: stable@vger.kernel.org Reviewed-by: Maxim Levitsky mlevitsk@redhat.com Link: https://lore.kernel.org/r/20220712135009.952805-1-vkuznets@redhat.com Signed-off-by: Sean Christopherson seanjc@google.com

diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c index 778f82015f03..bfa366938c49 100644 --- a/arch/x86/kvm/vmx/nested.c +++ b/arch/x86/kvm/vmx/nested.c @@ -2284,7 +2284,6 @@ 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,