This is a note to let you know that I've just added the patch titled
KVM: nVMX: Don't propagate vmcs12's PERF_GLOBAL_CTRL settings to vmcs02
to the 5.10-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-don-t-propagate-vmcs12-s-perf_global_ctrl-s.patch
and it can be found in the queue-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit a9675746749792878cf5cd6521d6b5b459e936df
Author: Sean Christopherson <seanjc@xxxxxxxxxx>
Date: Tue Aug 30 15:37:21 2022 +0200
KVM: nVMX: Don't propagate vmcs12's PERF_GLOBAL_CTRL settings to vmcs02
[ Upstream commit def9d705c05eab3fdedeb10ad67907513b12038e ]
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@xxxxxxxxxxxxxxx
Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
Signed-off-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20220830133737.1539624-18-vkuznets@xxxxxxxxxx
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index 2395387945a8..498fed0dda98 100644
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -2345,9 +2345,14 @@ 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)
