From: Sean Christopherson sean.j.christopherson@intel.com

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: stable@vger.kernel.org Cc: Liran Alon liran.alon@oracle.com Signed-off-by: Sean Christopherson sean.j.christopherson@intel.com Signed-off-by: Paolo Bonzini pbonzini@redhat.com --- arch/x86/kvm/vmx/nested.c | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c index fb7eddd64714..f2be64256f15 100644 --- a/arch/x86/kvm/vmx/nested.c +++ b/arch/x86/kvm/vmx/nested.c @@ -2228,13 +2228,9 @@ static void prepare_vmcs02_rare(struct vcpu_vmx *vmx, 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); }

/* @@ -2266,6 +2262,9 @@ 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); vmx_set_rflags(vcpu, vmcs12->guest_rflags);

/* EXCEPTION_BITMAP and CR0_GUEST_HOST_MASK should basically be the