4.18-stable review patch. If anyone has any objections, please let me know.
------------------
From: Sean Christopherson sean.j.christopherson@intel.com
commit fd6b6d9b82f97a851fb0078201ddc38fe9728cda upstream.
Return early from vmx_set_virtual_apic_mode() if the processor doesn't support VIRTUALIZE_APIC_ACCESSES or VIRTUALIZE_X2APIC_MODE, both of which reside in SECONDARY_VM_EXEC_CONTROL. This eliminates warnings due to VMWRITEs to SECONDARY_VM_EXEC_CONTROL (VMCS field 401e) failing on processors without secondary exec controls.
Remove the similar check for TPR shadowing as it is incorporated in the flexpriority_enabled check and the APIC-related code in vmx_update_msr_bitmap() is further gated by VIRTUALIZE_X2APIC_MODE.
Reported-by: Gerhard Wiesinger redhat@wiesinger.com Fixes: 8d860bbeedef ("kvm: vmx: Basic APIC virtualization controls have three settings") Cc: Jim Mattson jmattson@google.com Cc: stable@vger.kernel.org Signed-off-by: Sean Christopherson sean.j.christopherson@intel.com Signed-off-by: Paolo Bonzini pbonzini@redhat.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- arch/x86/kvm/vmx.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-)
--- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -9826,15 +9826,16 @@ static void vmx_set_virtual_apic_mode(st if (!lapic_in_kernel(vcpu)) return;
+ if (!flexpriority_enabled && + !cpu_has_vmx_virtualize_x2apic_mode()) + return; + /* Postpone execution until vmcs01 is the current VMCS. */ if (is_guest_mode(vcpu)) { to_vmx(vcpu)->nested.change_vmcs01_virtual_apic_mode = true; return; }
- if (!cpu_need_tpr_shadow(vcpu)) - return; - sec_exec_control = vmcs_read32(SECONDARY_VM_EXEC_CONTROL); sec_exec_control &= ~(SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES | SECONDARY_EXEC_VIRTUALIZE_X2APIC_MODE);