[PATCH 5.2 328/413] KVM: nVMX: Always sync GUEST_BNDCFGS when it comes from vmcs01

[Greg Kroah-Hartman]

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: stable@xxxxxxxxxxxxxxx
Cc: Liran Alon <liran.alon@xxxxxxxxxx>
Signed-off-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 arch/x86/kvm/vmx/nested.c |   13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)

--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -2234,13 +2234,9 @@ static void prepare_vmcs02_full(struct v
 
 	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);
 }
 
 /*
@@ -2283,6 +2279,9 @@ static int prepare_vmcs02(struct kvm_vcp
 		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