From: Sean Christopherson <sean.j.christopherson@xxxxxxxxx> commit 3b013a2972d5bc344d6eaa8f24fdfe268211e45f upstream. If L1 does not set VM_ENTRY_LOAD_BNDCFGS, then L1's BNDCFGS value must be propagated to vmcs02 since KVM always runs with VM_ENTRY_LOAD_BNDCFGS when MPX is supported. Because the value effectively comes from vmcs01, vmcs02 must be updated even if vmcs12 is clean. Fixes: 62cf9bd8118c4 ("KVM: nVMX: Fix emulation of VM_ENTRY_LOAD_BNDCFGS") Cc: Liran Alon <liran.alon@xxxxxxxxxx> Signed-off-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx> Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx> [bwh: Backported to 4.19: adjust filename, context] Signed-off-by: Ben Hutchings <ben.hutchings@xxxxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- arch/x86/kvm/vmx.c | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-) diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index e4d0ad06790e1..ccbddc80ad55f 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -12137,13 +12137,9 @@ static void prepare_vmcs02_full(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12) set_cr4_guest_host_mask(vmx); - if (kvm_mpx_supported()) { - if (vmx->nested.nested_run_pending && - (vmcs12->vm_entry_controls & VM_ENTRY_LOAD_BNDCFGS)) - vmcs_write64(GUEST_BNDCFGS, vmcs12->guest_bndcfgs); - else - vmcs_write64(GUEST_BNDCFGS, vmx->nested.vmcs01_guest_bndcfgs); - } + if (kvm_mpx_supported() && vmx->nested.nested_run_pending && + (vmcs12->vm_entry_controls & VM_ENTRY_LOAD_BNDCFGS)) + vmcs_write64(GUEST_BNDCFGS, vmcs12->guest_bndcfgs); if (enable_vpid) { if (nested_cpu_has_vpid(vmcs12) && vmx->nested.vpid02) @@ -12207,6 +12203,9 @@ static int prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12, kvm_set_dr(vcpu, 7, vcpu->arch.dr7); vmcs_write64(GUEST_IA32_DEBUGCTL, vmx->nested.vmcs01_debugctl); } + if (kvm_mpx_supported() && (!vmx->nested.nested_run_pending || + !(vmcs12->vm_entry_controls & VM_ENTRY_LOAD_BNDCFGS))) + vmcs_write64(GUEST_BNDCFGS, vmx->nested.vmcs01_guest_bndcfgs); if (vmx->nested.nested_run_pending) { vmcs_write32(VM_ENTRY_INTR_INFO_FIELD, vmcs12->vm_entry_intr_info_field); -- 2.20.1