KVM: nVMX: Initialize #VE info page for vmcs02 when proving #VE support

Point vmcs02.VE_INFORMATION_ADDRESS at the vCPU's #VE info page when
initializing vmcs02, otherwise KVM will run L2 with EPT Violation #VE
enabled and a VE info address pointing at pfn 0.

Fixes: 8131cf5 ("KVM: VMX: Introduce test mode related to EPT violation VE")
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-ID: <20240518000430.1118488-3-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Author: sean-jc

arch/x86/kvm/vmx/nested.c

@@ -2242,6 +2242,9 @@ static void prepare_vmcs02_constant_state(struct vcpu_vmx *vmx)
 		vmcs_write64(EPT_POINTER,
 			     construct_eptp(&vmx->vcpu, 0, PT64_ROOT_4LEVEL));
 
+	if (vmx->ve_info)
+		vmcs_write64(VE_INFORMATION_ADDRESS, __pa(vmx->ve_info));
+
 	/* All VMFUNCs are currently emulated through L0 vmexits.  */
 	if (cpu_has_vmx_vmfunc())
 		vmcs_write64(VM_FUNCTION_CONTROL, 0);