The patch below does not apply to the 5.10-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.
Possible dependencies:
def9d705c05e ("KVM: nVMX: Don't propagate vmcs12's PERF_GLOBAL_CTRL settings to vmcs02") 389ab25216c9 ("KVM: nVMX: Pull KVM L0's desired controls directly from vmcs01") d041b5ea9335 ("KVM: nVMX: Enable nested TSC scaling")
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From def9d705c05eab3fdedeb10ad67907513b12038e Mon Sep 17 00:00:00 2001 From: Sean Christopherson seanjc@google.com Date: Tue, 30 Aug 2022 15:37:21 +0200 Subject: [PATCH] KVM: nVMX: Don't propagate vmcs12's PERF_GLOBAL_CTRL settings to vmcs02
Don't propagate vmcs12's VM_ENTRY_LOAD_IA32_PERF_GLOBAL_CTRL to vmcs02. KVM doesn't disallow L1 from using VM_ENTRY_LOAD_IA32_PERF_GLOBAL_CTRL even when KVM itself doesn't use the control, e.g. due to the various CPU errata that where the MSR can be corrupted on VM-Exit.
Preserve KVM's (vmcs01) setting to hopefully avoid having to toggle the bit in vmcs02 at a later point. E.g. if KVM is loading PERF_GLOBAL_CTRL when running L1, then odds are good KVM will also load the MSR when running L2.
Fixes: 8bf00a529967 ("KVM: VMX: add support for switching of PERF_GLOBAL_CTRL") Cc: stable@vger.kernel.org Signed-off-by: Sean Christopherson seanjc@google.com Signed-off-by: Vitaly Kuznetsov vkuznets@redhat.com Link: https://lore.kernel.org/r/20220830133737.1539624-18-vkuznets@redhat.com Signed-off-by: Paolo Bonzini pbonzini@redhat.com
diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c index 1743319015b7..400e015afa64 100644 --- a/arch/x86/kvm/vmx/nested.c +++ b/arch/x86/kvm/vmx/nested.c @@ -2359,9 +2359,14 @@ static void prepare_vmcs02_early(struct vcpu_vmx *vmx, struct loaded_vmcs *vmcs0 * are emulated by vmx_set_efer() in prepare_vmcs02(), but speculate * on the related bits (if supported by the CPU) in the hope that * we can avoid VMWrites during vmx_set_efer(). + * + * Similarly, take vmcs01's PERF_GLOBAL_CTRL in the hope that if KVM is + * loading PERF_GLOBAL_CTRL via the VMCS for L1, then KVM will want to + * do the same for L2. */ exec_control = __vm_entry_controls_get(vmcs01); - exec_control |= vmcs12->vm_entry_controls; + exec_control |= (vmcs12->vm_entry_controls & + ~VM_ENTRY_LOAD_IA32_PERF_GLOBAL_CTRL); exec_control &= ~(VM_ENTRY_IA32E_MODE | VM_ENTRY_LOAD_IA32_EFER); if (cpu_has_load_ia32_efer()) { if (guest_efer & EFER_LMA)