KVM: nVMX: handle page fault in vmread

BugLink: https://bugs.launchpad.net/bugs/1845405

commit f7eea636 upstream.

The implementation of vmread to memory is still incomplete, as it
lacks the ability to do vmread to I/O memory just like vmptrst.

Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Connor Kuehl <connor.kuehl@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

arch/x86/kvm/vmx.c

@@ -7441,6 +7441,7 @@ static int handle_vmread(struct kvm_vcpu *vcpu)
 	unsigned long exit_qualification = vmcs_readl(EXIT_QUALIFICATION);
 	u32 vmx_instruction_info = vmcs_read32(VMX_INSTRUCTION_INFO);
 	gva_t gva = 0;
+	struct x86_exception e;
 
 	if (!nested_vmx_check_permission(vcpu) ||
 	    !nested_vmx_check_vmcs12(vcpu))
@@ -7467,8 +7468,10 @@ static int handle_vmread(struct kvm_vcpu *vcpu)
 				vmx_instruction_info, true, &gva))
 			return 1;
 		/* _system ok, as nested_vmx_check_permission verified cpl=0 */
-		kvm_write_guest_virt_system(vcpu, gva, &field_value,
-					    (is_long_mode(vcpu) ? 8 : 4), NULL);
+		if (kvm_write_guest_virt_system(vcpu, gva, &field_value,
+						(is_long_mode(vcpu) ? 8 : 4),
+						NULL))
+			kvm_inject_page_fault(vcpu, &e);
 	}
 
 	nested_vmx_succeed(vcpu);