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Kernel: Support multiport for VirtIOConsole

This involves refactoring VirtIOConsole into VirtIOConsole and
VirtIOConsolePort. VirtIOConsole is the VirtIODevice, it owns multiple
VirtIOConsolePorts as well as two control queues. Each
VirtIOConsolePort is a CharacterDevice.
This commit is contained in:
x-yl 2021-06-23 15:19:24 +04:00 committed by Ali Mohammad Pur
parent 1492bb2fd6
commit 1fe08759e3
6 changed files with 419 additions and 126 deletions

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@ -249,6 +249,7 @@ set(KERNEL_SOURCES
UserOrKernelBuffer.cpp
VirtIO/VirtIO.cpp
VirtIO/VirtIOConsole.cpp
VirtIO/VirtIOConsolePort.cpp
VirtIO/VirtIOQueue.cpp
VirtIO/VirtIORNG.cpp
VM/AnonymousVMObject.cpp

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@ -8,6 +8,7 @@
#include <AK/String.h>
#include <Kernel/PhysicalAddress.h>
#include <Kernel/UserOrKernelBuffer.h>
namespace Kernel {
@ -25,6 +26,8 @@ public:
SpinLock<u8>& lock() { return m_lock; }
size_t used_bytes() const { return m_num_used_bytes; }
PhysicalAddress start_of_region() const { return m_region->physical_page(0)->paddr(); }
VirtualAddress vaddr() const { return m_region->vaddr(); }
size_t bytes_till_end() const { return (m_capacity_in_bytes - ((m_start_of_used + m_num_used_bytes) % m_capacity_in_bytes)) % m_capacity_in_bytes; };
private:
OwnPtr<Region> m_region;

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@ -1,5 +1,6 @@
/*
* Copyright (c) 2021, the SerenityOS developers.
* Copyright (c) 2021, Kyle Pereira <hey@xylepereira.me>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
@ -12,8 +13,8 @@ namespace Kernel {
unsigned VirtIOConsole::next_device_id = 0;
UNMAP_AFTER_INIT VirtIOConsole::VirtIOConsole(PCI::Address address)
: CharacterDevice(229, next_device_id++)
, VirtIODevice(address, "VirtIOConsole")
: VirtIODevice(address, "VirtIOConsole")
, m_device_id(next_device_id++)
{
if (auto cfg = get_config(ConfigurationType::Device)) {
bool success = negotiate_features([&](u64 supported_features) {
@ -21,7 +22,7 @@ UNMAP_AFTER_INIT VirtIOConsole::VirtIOConsole(PCI::Address address)
if (is_feature_set(supported_features, VIRTIO_CONSOLE_F_SIZE))
dbgln("VirtIOConsole: Console size is not yet supported!");
if (is_feature_set(supported_features, VIRTIO_CONSOLE_F_MULTIPORT))
dbgln("VirtIOConsole: Multi port is not yet supported!");
negotiated |= VIRTIO_CONSOLE_F_MULTIPORT;
return negotiated;
});
if (success) {
@ -34,37 +35,24 @@ UNMAP_AFTER_INIT VirtIOConsole::VirtIOConsole(PCI::Address address)
}
if (is_feature_accepted(VIRTIO_CONSOLE_F_MULTIPORT)) {
max_nr_ports = config_read32(*cfg, 0x4);
m_ports.resize(max_nr_ports);
}
});
dbgln("VirtIOConsole: cols: {}, rows: {}, max nr ports {}", cols, rows, max_nr_ports);
success = setup_queues(2 + max_nr_ports * 2); // base receiveq/transmitq for port0 + 2 per every additional port
// Base receiveq/transmitq for port0 + optional control queues and 2 per every additional port
success = setup_queues(2 + max_nr_ports > 0 ? 2 + 2 * max_nr_ports : 0);
}
if (success) {
finish_init();
m_receive_buffer = make<RingBuffer>("VirtIOConsole Receive", RINGBUFFER_SIZE);
m_transmit_buffer = make<RingBuffer>("VirtIOConsole Transmit", RINGBUFFER_SIZE);
init_receive_buffer();
if (is_feature_accepted(VIRTIO_CONSOLE_F_MULTIPORT))
setup_multiport();
else
m_ports.append(new VirtIOConsolePort(0u, *this));
}
}
}
VirtIOConsole::~VirtIOConsole()
{
}
void VirtIOConsole::init_receive_buffer()
{
auto& queue = get_queue(RECEIVEQ);
ScopedSpinLock queue_lock(queue.lock());
VirtIOQueueChain chain(queue);
auto buffer_start = m_receive_buffer->start_of_region();
auto did_add_buffer = chain.add_buffer_to_chain(buffer_start, RINGBUFFER_SIZE, BufferType::DeviceWritable);
VERIFY(did_add_buffer);
supply_chain_and_notify(RECEIVEQ, chain);
}
bool VirtIOConsole::handle_device_config_change()
{
dbgln("VirtIOConsole: Handle device config change");
@ -73,112 +61,158 @@ bool VirtIOConsole::handle_device_config_change()
void VirtIOConsole::handle_queue_update(u16 queue_index)
{
dbgln_if(VIRTIO_DEBUG, "VirtIOConsole: Handle queue update");
VERIFY(queue_index <= TRANSMITQ);
switch (queue_index) {
case RECEIVEQ: {
auto& queue = get_queue(RECEIVEQ);
dbgln_if(VIRTIO_DEBUG, "VirtIOConsole: Handle queue update {}", queue_index);
if (queue_index == CONTROL_RECEIVEQ) {
ScopedSpinLock ringbuffer_lock(m_control_receive_buffer->lock());
auto& queue = get_queue(CONTROL_RECEIVEQ);
ScopedSpinLock queue_lock(queue.lock());
size_t used;
VirtIOQueueChain popped_chain = queue.pop_used_buffer_chain(used);
ScopedSpinLock ringbuffer_lock(m_receive_buffer->lock());
while (!popped_chain.is_empty()) {
popped_chain.for_each([&](auto addr, auto) {
auto offset = addr.as_ptr() - m_control_receive_buffer->start_of_region().as_ptr();
auto* message = reinterpret_cast<ControlMessage*>(m_control_receive_buffer->vaddr().offset(offset).as_ptr());
process_control_message(*message);
});
auto used_space = m_receive_buffer->reserve_space(used).value();
auto remaining_space = RINGBUFFER_SIZE - used;
// Our algorithm always has only one buffer in the queue.
VERIFY(!queue.new_data_available());
popped_chain.release_buffer_slots_to_queue();
VirtIOQueueChain new_chain(queue);
if (remaining_space != 0) {
new_chain.add_buffer_to_chain(used_space.offset(used), remaining_space, BufferType::DeviceWritable);
supply_chain_and_notify(RECEIVEQ, new_chain);
supply_chain_and_notify(CONTROL_RECEIVEQ, popped_chain);
popped_chain = queue.pop_used_buffer_chain(used);
}
evaluate_block_conditions();
break;
}
case TRANSMITQ: {
ScopedSpinLock ringbuffer_lock(m_transmit_buffer->lock());
auto& queue = get_queue(TRANSMITQ);
} else if (queue_index == CONTROL_TRANSMITQ) {
ScopedSpinLock ringbuffer_lock(m_control_transmit_buffer->lock());
auto& queue = get_queue(CONTROL_TRANSMITQ);
ScopedSpinLock queue_lock(queue.lock());
size_t used;
VirtIOQueueChain popped_chain = queue.pop_used_buffer_chain(used);
auto number_of_messages = 0;
do {
popped_chain.for_each([this](PhysicalAddress address, size_t length) {
m_transmit_buffer->reclaim_space(address, length);
m_control_transmit_buffer->reclaim_space(address, length);
});
popped_chain.release_buffer_slots_to_queue();
popped_chain = queue.pop_used_buffer_chain(used);
number_of_messages++;
} while (!popped_chain.is_empty());
// Unblock any IO tasks that were blocked because can_write() returned false
evaluate_block_conditions();
m_control_wait_queue.wake_n(number_of_messages);
} else {
u32 port_index = queue_index < 2 ? 0 : (queue_index - 2) / 2;
if (port_index >= m_ports.size() || !m_ports.at(port_index)) {
dbgln("Invalid queue_index {}", queue_index);
return;
}
m_ports.at(port_index)->handle_queue_update({}, queue_index);
}
}
void VirtIOConsole::setup_multiport()
{
m_control_receive_buffer = make<RingBuffer>("VirtIOConsole control receive queue", CONTROL_BUFFER_SIZE);
m_control_transmit_buffer = make<RingBuffer>("VirtIOConsole control transmit queue", CONTROL_BUFFER_SIZE);
auto& queue = get_queue(CONTROL_RECEIVEQ);
ScopedSpinLock queue_lock(queue.lock());
VirtIOQueueChain chain(queue);
auto offset = 0ul;
while (offset < CONTROL_BUFFER_SIZE) {
auto buffer_start = m_control_receive_buffer->start_of_region().offset(offset);
auto did_add_buffer = chain.add_buffer_to_chain(buffer_start, CONTROL_MESSAGE_SIZE, BufferType::DeviceWritable);
VERIFY(did_add_buffer);
offset += CONTROL_MESSAGE_SIZE;
supply_chain_and_notify(CONTROL_RECEIVEQ, chain);
}
ControlMessage ready_event {
.id = 0, // Unused
.event = (u16)ControlEvent::DeviceReady,
.value = (u16)ControlMessage::Status::Success
};
write_control_message(ready_event);
}
void VirtIOConsole::process_control_message(ControlMessage message)
{
switch (message.event) {
case (u16)ControlEvent::DeviceAdd: {
u32 id = message.id;
if (id >= m_ports.size()) {
dbgln("Device provided an invalid port number {}. max_nr_ports: {}", id, m_ports.size());
return;
} else if (!m_ports.at(id).is_null()) {
dbgln("Device tried to add port {} which was already added!", id);
return;
}
m_ports.at(id) = new VirtIOConsolePort(id, *this);
ControlMessage ready_event {
.id = static_cast<u32>(id),
.event = (u16)ControlEvent::PortReady,
.value = (u16)ControlMessage::Status::Success
};
write_control_message(ready_event);
break;
}
case (u16)ControlEvent::ConsolePort:
case (u16)ControlEvent::PortOpen: {
if (message.id >= m_ports.size()) {
dbgln("Device provided an invalid port number {}. max_nr_ports: {}", message.id, m_ports.size());
return;
} else if (m_ports.at(message.id).is_null()) {
dbgln("Device tried to open port {} which was not added!", message.id);
return;
}
if (message.value == (u16)ControlMessage::PortStatus::Open) {
auto is_open = m_ports.at(message.id)->is_open();
if (!is_open) {
m_ports.at(message.id)->set_open({}, true);
send_open_control_message(message.id, true);
}
} else if (message.value == (u16)ControlMessage::PortStatus::Close) {
m_ports.at(message.id)->set_open({}, false);
} else {
dbgln("Device specified invalid value {}. Must be 0 or 1.", message.value);
}
break;
}
default:
VERIFY_NOT_REACHED();
dbgln("Unhandled message event {}!", message.event);
}
}
bool VirtIOConsole::can_read(const FileDescription&, size_t) const
void VirtIOConsole::write_control_message(ControlMessage message)
{
return m_receive_buffer->used_bytes() > 0;
}
ScopedSpinLock ringbuffer_lock(m_control_transmit_buffer->lock());
KResultOr<size_t> VirtIOConsole::read(FileDescription& desc, u64, UserOrKernelBuffer& buffer, size_t size)
{
if (!size)
return 0;
PhysicalAddress start_of_chunk;
size_t length_of_chunk;
if (!can_read(desc, size))
return EAGAIN;
auto data = UserOrKernelBuffer::for_kernel_buffer((u8*)&message);
while (!m_control_transmit_buffer->copy_data_in(data, 0, sizeof(message), start_of_chunk, length_of_chunk)) {
ringbuffer_lock.unlock();
m_control_wait_queue.wait_forever();
ringbuffer_lock.lock();
}
ScopedSpinLock ringbuffer_lock(m_receive_buffer->lock());
auto bytes_copied = m_receive_buffer->copy_data_out(size, buffer);
m_receive_buffer->reclaim_space(m_receive_buffer->start_of_used(), bytes_copied.value());
return bytes_copied;
}
bool VirtIOConsole::can_write(const FileDescription&, size_t) const
{
return get_queue(TRANSMITQ).has_free_slots() && m_transmit_buffer->has_space();
}
KResultOr<size_t> VirtIOConsole::write(FileDescription& desc, u64, const UserOrKernelBuffer& data, size_t size)
{
if (!size)
return 0;
if (!can_write(desc, size))
return EAGAIN;
ScopedSpinLock ringbuffer_lock(m_transmit_buffer->lock());
auto& queue = get_queue(TRANSMITQ);
auto& queue = get_queue(CONTROL_TRANSMITQ);
ScopedSpinLock queue_lock(queue.lock());
VirtIOQueueChain chain(queue);
size_t total_bytes_copied = 0;
do {
PhysicalAddress start_of_chunk;
size_t length_of_chunk;
bool did_add_buffer = chain.add_buffer_to_chain(start_of_chunk, length_of_chunk, BufferType::DeviceReadable);
VERIFY(did_add_buffer);
if (!m_transmit_buffer->copy_data_in(data, total_bytes_copied, size - total_bytes_copied, start_of_chunk, length_of_chunk)) {
chain.release_buffer_slots_to_queue();
return EINVAL;
}
bool did_add_buffer = chain.add_buffer_to_chain(start_of_chunk, length_of_chunk, BufferType::DeviceReadable);
VERIFY(did_add_buffer);
total_bytes_copied += length_of_chunk;
} while (total_bytes_copied < size && can_write(desc, size - total_bytes_copied));
supply_chain_and_notify(TRANSMITQ, chain);
return total_bytes_copied;
supply_chain_and_notify(CONTROL_TRANSMITQ, chain);
}
void VirtIOConsole::send_open_control_message(unsigned port_number, bool open)
{
ControlMessage port_open {
.id = static_cast<u32>(port_number),
.event = (u16)ControlEvent::PortOpen,
.value = open
};
write_control_message(port_open);
}
}

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@ -1,4 +1,5 @@
/*
* Copyright (c) 2021, Kyle Pereira <hey@xylepereira.me>
* Copyright (c) 2021, the SerenityOS developers.
*
* SPDX-License-Identifier: BSD-2-Clause
@ -6,48 +7,72 @@
#pragma once
#include <Kernel/Devices/CharacterDevice.h>
#include <Kernel/VM/RingBuffer.h>
#include <Kernel/VirtIO/VirtIO.h>
#include <Kernel/VirtIO/VirtIOConsolePort.h>
namespace Kernel {
class VirtIOConsole
: public VirtIODevice
, public RefCounted<VirtIOConsole> {
friend VirtIOConsolePort;
#define VIRTIO_CONSOLE_F_SIZE (1 << 0)
#define VIRTIO_CONSOLE_F_MULTIPORT (1 << 1)
#define VIRTIO_CONSOLE_F_EMERG_WRITE (1 << 2)
#define RECEIVEQ 0
#define TRANSMITQ 1
class VirtIOConsole final : public CharacterDevice
, public VirtIODevice {
public:
VirtIOConsole(PCI::Address);
virtual ~VirtIOConsole() override;
virtual ~VirtIOConsole() override = default;
virtual const char* purpose() const override { return class_name(); }
virtual const char* purpose() const override { return "VirtIOConsole"; }
unsigned device_id() const
{
return m_device_id;
}
private:
constexpr static size_t RINGBUFFER_SIZE = 2 * PAGE_SIZE;
virtual const char* class_name() const override { return m_class_name.characters(); }
enum class ControlEvent : u16 {
DeviceReady = 0,
DeviceAdd = 1,
PortReady = 3,
ConsolePort = 4,
PortOpen = 6,
};
struct [[gnu::packed]] ControlMessage {
u32 id;
u16 event;
u16 value;
virtual bool can_read(const FileDescription&, size_t) const override;
virtual KResultOr<size_t> read(FileDescription&, u64, UserOrKernelBuffer&, size_t) override;
virtual bool can_write(const FileDescription&, size_t) const override;
virtual KResultOr<size_t> write(FileDescription&, u64, const UserOrKernelBuffer&, size_t) override;
enum class Status : u16 {
Success = 1,
Failure = 0
};
virtual mode_t required_mode() const override { return 0666; }
enum class PortStatus : u16 {
Open = 1,
Close = 0
};
};
constexpr static u16 CONTROL_RECEIVEQ = 2;
constexpr static u16 CONTROL_TRANSMITQ = 3;
constexpr static size_t CONTROL_MESSAGE_SIZE = sizeof(ControlMessage);
constexpr static size_t CONTROL_BUFFER_SIZE = CONTROL_MESSAGE_SIZE * 32;
virtual bool handle_device_config_change() override;
virtual String device_name() const override { return String::formatted("hvc{}", minor()); }
virtual void handle_queue_update(u16 queue_index) override;
void init_receive_buffer();
OwnPtr<RingBuffer> m_receive_buffer;
OwnPtr<RingBuffer> m_transmit_buffer;
Vector<RefPtr<VirtIOConsolePort>> m_ports;
void setup_multiport();
void process_control_message(ControlMessage message);
void write_control_message(ControlMessage message);
void send_open_control_message(unsigned port_number, bool open);
unsigned m_device_id;
OwnPtr<RingBuffer> m_control_transmit_buffer;
OwnPtr<RingBuffer> m_control_receive_buffer;
WaitQueue m_control_wait_queue;
static unsigned next_device_id;
};
}

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@ -0,0 +1,167 @@
/*
* Copyright (c) 2021, the SerenityOS developers.
* Copyright (c) 2021, Kyle Pereira <hey@xylepereira.me>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <Kernel/VirtIO/VirtIOConsole.h>
#include <Kernel/VirtIO/VirtIOConsolePort.h>
namespace Kernel {
unsigned VirtIOConsolePort::next_device_id = 0;
VirtIOConsolePort::VirtIOConsolePort(unsigned port, VirtIOConsole& console)
: CharacterDevice(229, next_device_id++)
, m_console(console)
, m_port(port)
{
m_receive_buffer = make<RingBuffer>("VirtIOConsolePort Receive", RINGBUFFER_SIZE);
m_transmit_buffer = make<RingBuffer>("VirtIOConsolePort Transmit", RINGBUFFER_SIZE);
m_receive_queue = m_port == 0 ? 0 : m_port * 2 + 2;
m_transmit_queue = m_port == 0 ? 1 : m_port * 2 + 3;
init_receive_buffer();
}
void VirtIOConsolePort::init_receive_buffer()
{
auto& queue = m_console.get_queue(m_receive_queue);
ScopedSpinLock queue_lock(queue.lock());
VirtIOQueueChain chain(queue);
auto buffer_start = m_receive_buffer->start_of_region();
auto did_add_buffer = chain.add_buffer_to_chain(buffer_start, RINGBUFFER_SIZE, BufferType::DeviceWritable);
VERIFY(did_add_buffer);
m_console.supply_chain_and_notify(m_receive_queue, chain);
}
void VirtIOConsolePort::handle_queue_update(Badge<VirtIOConsole>, u16 queue_index)
{
dbgln_if(VIRTIO_DEBUG, "VirtIOConsolePort: Handle queue update for port {}", m_port);
VERIFY(queue_index == m_transmit_queue || queue_index == m_receive_queue);
if (queue_index == m_receive_queue) {
auto& queue = m_console.get_queue(m_receive_queue);
ScopedSpinLock queue_lock(queue.lock());
size_t used;
VirtIOQueueChain popped_chain = queue.pop_used_buffer_chain(used);
ScopedSpinLock ringbuffer_lock(m_receive_buffer->lock());
auto used_space = m_receive_buffer->reserve_space(used).value();
auto remaining_space = m_receive_buffer->bytes_till_end();
// Our algorithm always has only one buffer in the queue.
VERIFY(popped_chain.length() == 1);
VERIFY(!queue.new_data_available());
popped_chain.release_buffer_slots_to_queue();
VirtIOQueueChain new_chain(queue);
if (remaining_space != 0) {
new_chain.add_buffer_to_chain(used_space.offset(used), remaining_space, BufferType::DeviceWritable);
m_console.supply_chain_and_notify(m_receive_queue, new_chain);
} else {
m_receive_buffer_exhausted = true;
}
evaluate_block_conditions();
} else {
ScopedSpinLock ringbuffer_lock(m_transmit_buffer->lock());
auto& queue = m_console.get_queue(m_transmit_queue);
ScopedSpinLock queue_lock(queue.lock());
size_t used;
VirtIOQueueChain popped_chain = queue.pop_used_buffer_chain(used);
do {
popped_chain.for_each([this](PhysicalAddress address, size_t length) {
m_transmit_buffer->reclaim_space(address, length);
});
popped_chain.release_buffer_slots_to_queue();
popped_chain = queue.pop_used_buffer_chain(used);
} while (!popped_chain.is_empty());
// Unblock any IO tasks that were blocked because can_write() returned false
evaluate_block_conditions();
}
}
bool VirtIOConsolePort::can_read(const FileDescription&, size_t) const
{
return m_receive_buffer->used_bytes() > 0;
}
KResultOr<size_t> VirtIOConsolePort::read(FileDescription& desc, u64, UserOrKernelBuffer& buffer, size_t size)
{
if (!size)
return 0;
ScopedSpinLock ringbuffer_lock(m_receive_buffer->lock());
if (!can_read(desc, size))
return EAGAIN;
auto bytes_copied = m_receive_buffer->copy_data_out(size, buffer).value();
m_receive_buffer->reclaim_space(m_receive_buffer->start_of_used(), bytes_copied);
if (m_receive_buffer_exhausted && m_receive_buffer->used_bytes() == 0) {
auto& queue = m_console.get_queue(m_receive_queue);
ScopedSpinLock queue_lock(queue.lock());
VirtIOQueueChain new_chain(queue);
new_chain.add_buffer_to_chain(m_receive_buffer->start_of_region(), RINGBUFFER_SIZE, BufferType::DeviceWritable);
m_console.supply_chain_and_notify(m_receive_queue, new_chain);
m_receive_buffer_exhausted = false;
}
return bytes_copied;
}
bool VirtIOConsolePort::can_write(const FileDescription&, size_t) const
{
return m_console.get_queue(m_transmit_queue).has_free_slots() && m_transmit_buffer->has_space();
}
KResultOr<size_t> VirtIOConsolePort::write(FileDescription& desc, u64, const UserOrKernelBuffer& data, size_t size)
{
if (!size)
return 0;
ScopedSpinLock ringbuffer_lock(m_transmit_buffer->lock());
auto& queue = m_console.get_queue(m_transmit_queue);
ScopedSpinLock queue_lock(queue.lock());
if (!can_write(desc, size))
return EAGAIN;
VirtIOQueueChain chain(queue);
size_t total_bytes_copied = 0;
do {
PhysicalAddress start_of_chunk;
size_t length_of_chunk;
if (!m_transmit_buffer->copy_data_in(data, total_bytes_copied, size - total_bytes_copied, start_of_chunk, length_of_chunk)) {
chain.release_buffer_slots_to_queue();
return EINVAL;
}
bool did_add_buffer = chain.add_buffer_to_chain(start_of_chunk, length_of_chunk, BufferType::DeviceReadable);
VERIFY(did_add_buffer);
total_bytes_copied += length_of_chunk;
} while (total_bytes_copied < size && can_write(desc, size));
m_console.supply_chain_and_notify(m_transmit_queue, chain);
return total_bytes_copied;
}
String VirtIOConsolePort::device_name() const
{
return String::formatted("hvc{}p{}", m_console.device_id(), m_port);
}
KResultOr<NonnullRefPtr<FileDescription>> VirtIOConsolePort::open(int options)
{
if (m_open)
m_console.send_open_control_message(m_port, true);
return File::open(options);
}
}

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@ -0,0 +1,63 @@
/*
* Copyright (c) 2021, the SerenityOS developers.
* Copyright (c) 2021, Kyle Pereira <hey@xylepereira.me>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <Kernel/Devices/CharacterDevice.h>
#include <Kernel/FileSystem/FileDescription.h>
#include <Kernel/VM/RingBuffer.h>
#include <Kernel/VirtIO/VirtIO.h>
namespace Kernel {
class VirtIOConsole;
#define VIRTIO_CONSOLE_F_SIZE (1 << 0)
#define VIRTIO_CONSOLE_F_MULTIPORT (1 << 1)
#define VIRTIO_CONSOLE_F_EMERG_WRITE (1 << 2)
class VirtIOConsolePort
: public CharacterDevice {
public:
explicit VirtIOConsolePort(unsigned port, VirtIOConsole&);
void handle_queue_update(Badge<VirtIOConsole>, u16 queue_index);
void set_open(Badge<VirtIOConsole>, bool state) { m_open = state; }
bool is_open() const { return m_open; }
private:
constexpr static size_t RINGBUFFER_SIZE = 2 * PAGE_SIZE;
virtual const char* class_name() const override { return "VirtIOConsolePort"; }
virtual bool can_read(const FileDescription&, size_t) const override;
virtual KResultOr<size_t> read(FileDescription&, u64, UserOrKernelBuffer&, size_t) override;
virtual bool can_write(const FileDescription&, size_t) const override;
virtual KResultOr<size_t> write(FileDescription&, u64, const UserOrKernelBuffer&, size_t) override;
virtual KResultOr<NonnullRefPtr<FileDescription>> open(int options) override;
mode_t required_mode() const override { return 0666; }
String device_name() const override;
void init_receive_buffer();
static unsigned next_device_id;
u16 m_receive_queue {};
u16 m_transmit_queue {};
OwnPtr<RingBuffer> m_receive_buffer;
OwnPtr<RingBuffer> m_transmit_buffer;
VirtIOConsole& m_console;
unsigned m_port;
bool m_open { false };
Atomic<bool> m_receive_buffer_exhausted;
};
}