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serenity/Kernel/Bus/VirtIO/RNG.h
Liav A ed6c1f53af Kernel/VirtIO: Defer initialization of device out of the constructor
This ensures we safely handle interrupts (which can call virtual
functions), so they don't happen in the constructor - this pattern can
lead to a crash, if we are still in the constructor context because
not all methods are available for usage (some are pure virtual,
so it's possible to call __cxa_pure_virtual).

Also, under some conditions like adding a PCI device via PCI-passthrough
mechanism in QEMU, it became exposed to the eye that the code asserts on
RNG::handle_device_config_change(). That device has no configuration but
if the hypervisor still misbehaves and tries to configure it, we should
simply return false to indicate nothing happened.
2021-09-04 16:36:02 +02:00

39 lines
970 B
C++

/*
* Copyright (c) 2021, the SerenityOS developers.
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <AK/RefCounted.h>
#include <Kernel/Bus/VirtIO/Device.h>
#include <Kernel/Devices/CharacterDevice.h>
#include <Kernel/Random.h>
namespace Kernel::VirtIO {
#define REQUESTQ 0
class RNG final
: public RefCounted<RNG>
, public VirtIO::Device {
public:
static NonnullRefPtr<RNG> must_create(PCI::Address address);
virtual StringView purpose() const override { return class_name(); }
virtual ~RNG() override = default;
virtual void initialize() override;
private:
virtual StringView class_name() const override { return "VirtIOConsole"; }
explicit RNG(PCI::Address);
virtual bool handle_device_config_change() override;
virtual void handle_queue_update(u16 queue_index) override;
void request_entropy_from_host();
OwnPtr<Memory::Region> m_entropy_buffer;
EntropySource m_entropy_source;
};
}