[PATCH 4.18 052/150] KVM: nVMX: Fix emulation of VM_ENTRY_LOAD_BNDCFGS

[Greg Kroah-Hartman]

4.18-stable review patch.  If anyone has any objections, please let me know.

------------------

[ Upstream commit 62cf9bd8118c4009f02c477ef78c723f49e53e16 ]

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@xxxxxxxxxx>
Reviewed-by: Darren Kenny <darren.kenny@xxxxxxxxxx>
Signed-off-by: Liran Alon <liran.alon@xxxxxxxxxx>
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 arch/x86/kvm/vmx.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 2e23fce5eb1f..9efe130ea2e6 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -819,6 +819,7 @@ 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;
@@ -11567,8 +11568,13 @@ 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)
@@ -12082,6 +12088,9 @@ static int enter_vmx_non_root_mode(struct kvm_vcpu *vcpu)
 
 	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);
-- 
2.17.1