From b596af363c30de5323641fab69ad50c712f526e2 Mon Sep 17 00:00:00 2001
From: Liav A <liavalb@gmail.com>
Date: Fri, 27 Aug 2021 11:09:04 +0300
Subject: [PATCH] Kernel/VirtIO: Make RNG device to not be a CharacterDevice

This class as a CharacterDevice really was not useful, because you
couldn't even read from it.
Also, the random number generator interface should be the /dev/random,
so any other interface to get random numbers is generally not a good
idea.
Instead, let's keep this functionality as an entropy source for random
numbers generation, but without exposing a device node.
---
 Kernel/Bus/VirtIO/VirtIORNG.cpp |  3 +--
 Kernel/Bus/VirtIO/VirtIORNG.h   | 15 ++++-----------
 2 files changed, 5 insertions(+), 13 deletions(-)

diff --git a/Kernel/Bus/VirtIO/VirtIORNG.cpp b/Kernel/Bus/VirtIO/VirtIORNG.cpp
index 560ab0a075..94fb060ec3 100644
--- a/Kernel/Bus/VirtIO/VirtIORNG.cpp
+++ b/Kernel/Bus/VirtIO/VirtIORNG.cpp
@@ -10,8 +10,7 @@
 namespace Kernel {
 
 UNMAP_AFTER_INIT VirtIORNG::VirtIORNG(PCI::Address address)
-    : CharacterDevice(10, 183)
-    , VirtIODevice(address, "VirtIORNG")
+    : VirtIODevice(address, "VirtIORNG")
 {
     bool success = negotiate_features([&](auto) {
         return 0;
diff --git a/Kernel/Bus/VirtIO/VirtIORNG.h b/Kernel/Bus/VirtIO/VirtIORNG.h
index 12a2223a68..b43a4267a3 100644
--- a/Kernel/Bus/VirtIO/VirtIORNG.h
+++ b/Kernel/Bus/VirtIO/VirtIORNG.h
@@ -6,6 +6,7 @@
 
 #pragma once
 
+#include <AK/RefCounted.h>
 #include <Kernel/Bus/VirtIO/VirtIO.h>
 #include <Kernel/Devices/CharacterDevice.h>
 #include <Kernel/Random.h>
@@ -14,19 +15,11 @@ namespace Kernel {
 
 #define REQUESTQ 0
 
-class VirtIORNG final : public CharacterDevice
+class VirtIORNG final
+    : public RefCounted<VirtIORNG>
     , public VirtIODevice {
 public:
-    virtual StringView purpose() const override { return class_name(); }
-    virtual StringView class_name() const override { return m_class_name; }
-
-    virtual bool can_read(const FileDescription&, size_t) const override { return false; }
-    virtual KResultOr<size_t> read(FileDescription&, u64, UserOrKernelBuffer&, size_t) override { return 0; }
-    virtual bool can_write(const FileDescription&, size_t) const override { return false; }
-    virtual KResultOr<size_t> write(FileDescription&, u64, const UserOrKernelBuffer&, size_t) override { return 0; }
-
-    virtual mode_t required_mode() const override { return 0666; }
-    virtual String device_name() const override { return "hwrng"; }
+    virtual StringView purpose() const override { return m_class_name; }
 
     VirtIORNG(PCI::Address);
     virtual ~VirtIORNG() override;