KVM: nVMX: Fix emulation of VM_ENTRY_LOAD_BNDCFGS

L2 IA32_BNDCFGS should be updated with vmcs12->guest_bndcfgs only
when VM_ENTRY_LOAD_BNDCFGS is specified in vmcs12->vm_entry_controls.

Otherwise, L2 IA32_BNDCFGS should be set to vmcs01->guest_bndcfgs which
is L1 IA32_BNDCFGS.

Reviewed-by: Nikita Leshchenko <nikita.leshchenko@oracle.com>
Reviewed-by: Darren Kenny <darren.kenny@oracle.com>
Signed-off-by: Liran Alon <liran.alon@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 5bb2acd..b16b266 100644 (file)
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -856,6 +856,7 @@ struct nested_vmx {
 
        /* to migrate it to L2 if VM_ENTRY_LOAD_DEBUG_CONTROLS is off */
        u64 vmcs01_debugctl;
+       u64 vmcs01_guest_bndcfgs;
 
        u16 vpid02;
        u16 last_vpid;
@@ -12036,8 +12037,13 @@ static void prepare_vmcs02_full(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12)
 
        set_cr4_guest_host_mask(vmx);
 
-       if (kvm_mpx_supported())
-               vmcs_write64(GUEST_BNDCFGS, vmcs12->guest_bndcfgs);
+       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 (enable_vpid) {
                if (nested_cpu_has_vpid(vmcs12) && vmx->nested.vpid02)
@@ -12591,6 +12597,9 @@ static int enter_vmx_non_root_mode(struct kvm_vcpu *vcpu, u32 *exit_qual)
 
        if (!(vmcs12->vm_entry_controls & VM_ENTRY_LOAD_DEBUG_CONTROLS))
                vmx->nested.vmcs01_debugctl = vmcs_read64(GUEST_IA32_DEBUGCTL);
+       if (kvm_mpx_supported() &&
+               !(vmcs12->vm_entry_controls & VM_ENTRY_LOAD_BNDCFGS))
+               vmx->nested.vmcs01_guest_bndcfgs = vmcs_read64(GUEST_BNDCFGS);
 
        vmx_switch_vmcs(vcpu, &vmx->nested.vmcs02);
        vmx_segment_cache_clear(vmx);