FAILED: patch "[PATCH] KVM: nVMX: Always enable TSC scaling for L2 when it was" failed to apply to 5.19-stable tree
Subsystems (3)
[email protected]
maintainerThe 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 <[email protected]>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 156b9d76e8822f2956c15029acf2d4b171502f3a Mon Sep 17 00:00:00 2001
From: Vitaly Kuznetsov <[email protected]>
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().
arch/x86/kvm/vmx/nested.c +0 -1
@@ -2284,7 +2284,6 @@ static void prepare_vmcs02_early(struct vcpu_vmx *vmx, struct loaded_vmcs *vmcs0SECONDARY_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,