This is a note to let you know that I've just added the patch titled
KVM: nVMX: Always enable TSC scaling for L2 when it was enabled for L1
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
kvm-nvmx-always-enable-tsc-scaling-for-l2-when-it-was-enabled-for-l1.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 156b9d76e8822f2956c15029acf2d4b171502f3a Mon Sep 17 00:00:00 2001
From: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
Date: Tue, 12 Jul 2022 15:50:09 +0200
Subject: KVM: nVMX: Always enable TSC scaling for L2 when it was enabled for L1
From: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
commit 156b9d76e8822f2956c15029acf2d4b171502f3a upstream.
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@xxxxxxxxxx>
Fixes: d041b5ea93352b ("KVM: nVMX: Enable nested TSC scaling")
Cc: stable@xxxxxxxxxxxxxxx
Reviewed-by: Maxim Levitsky <mlevitsk@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20220712135009.952805-1-vkuznets@xxxxxxxxxx
Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/x86/kvm/vmx/nested.c | 1 -
1 file changed, 1 deletion(-)
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -2273,7 +2273,6 @@ static void prepare_vmcs02_early(struct
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,
Patches currently in stable-queue which might be from vkuznets@xxxxxxxxxx are
queue-5.15/kvm-nvmx-always-enable-tsc-scaling-for-l2-when-it-was-enabled-for-l1.patch
