[PATCH 1/2] KVM: nVMX: Don't clobber VM-Entry instruction length when saving soft INTn

[ma.mandourr@gmail.com]

From: Mahmoud Abumandour <ma.mandourr@gmail.com>

When a VM-Exit from L2 occurs while vectoring a software interrupt, write
the instruction length to vmcs12's VM-Exit instruction length field, as is
done for software exceptions, not to the VM-Entry instruction length field,
which belongs to L1.

Found with a differential testing harness for VMX isolation.

Fixes: 5f3d5799974b ("KVM: nVMX: Rework event injection and recovery")
Signed-off-by: Mahmoud Abumandour <ma.mandourr@gmail.com>
---
 arch/x86/kvm/vmx/nested.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index 9b0bfa2f854c..302f5b5aa582 100644
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -4016,7 +4016,7 @@ static void vmcs12_save_pending_event(struct kvm_vcpu *vcpu,
 
 		if (vcpu->arch.interrupt.soft) {
 			idt_vectoring |= INTR_TYPE_SOFT_INTR;
-			vmcs12->vm_entry_instruction_len =
+			vmcs12->vm_exit_instruction_len =
 				vcpu->arch.event_exit_inst_len;
 		} else
 			idt_vectoring |= INTR_TYPE_EXT_INTR;
-- 
2.43.0