Virtio MMIO 传输层 More...

#include <mmio.hpp>

Inheritance diagram for virtio::MmioTransport:

Collaboration diagram for virtio::MmioTransport:

Public Types
enum class	MmioReg : size_t { kMagicValue = 0x000 , kVersion = 0x004 , kDeviceId = 0x008 , kVendorId = 0x00C , kDeviceFeatures = 0x010 , kDeviceFeaturesSel = 0x014 , kDriverFeatures = 0x020 , kDriverFeaturesSel = 0x024 , kQueueSel = 0x030 , kQueueNumMax = 0x034 , kQueueNum = 0x038 , kQueueReady = 0x044 , kQueueNotify = 0x050 , kInterruptStatus = 0x060 , kInterruptAck = 0x064 , kStatus = 0x070 , kQueueDescLow = 0x080 , kQueueDescHigh = 0x084 , kQueueDriverLow = 0x090 , kQueueDriverHigh = 0x094 , kQueueDeviceLow = 0x0A0 , kQueueDeviceHigh = 0x0A4 , kShmSel = 0x0AC , kShmLenLow = 0x0B0 , kShmLenHigh = 0x0B4 , kShmBaseLow = 0x0B8 , kShmBaseHigh = 0x0BC , kQueueReset = 0x0C0 , kConfigGeneration = 0x0FC , kConfig = 0x100 }
	MMIO 寄存器偏移量 More...

Public Types inherited from virtio::Transport
enum class	DeviceStatus : uint32_t { kReset = 0 , kAcknowledge = 1 , kDriver = 2 , kDriverOk = 4 , kFeaturesOk = 8 , kDeviceNeedsReset = 64 , kFailed = 128 }
	设备状态位定义 More...

Public Member Functions
	MmioTransport (uint64_t base)
	构造函数

auto	IsValid () const -> bool
	检查设备是否成功初始化

auto	GetDeviceId () const -> uint32_t

auto	GetVendorId () const -> uint32_t

auto	GetStatus () const -> uint32_t

auto	SetStatus (uint32_t status) -> void

auto	GetDeviceFeatures () -> uint64_t
	读取 64 位设备特性

auto	SetDriverFeatures (uint64_t features) -> void
	写入 64 位驱动特性

auto	GetQueueNumMax (uint32_t queue_idx) -> uint32_t
	获取队列最大容量

auto	SetQueueNum (uint32_t queue_idx, uint32_t num) -> void

auto	SetQueueDesc (uint32_t queue_idx, uint64_t addr) -> void
	设置描述符表物理地址

auto	SetQueueAvail (uint32_t queue_idx, uint64_t addr) -> void
	设置 Available Ring 物理地址

auto	SetQueueUsed (uint32_t queue_idx, uint64_t addr) -> void
	设置 Used Ring 物理地址

auto	GetQueueReady (uint32_t queue_idx) -> bool

auto	SetQueueReady (uint32_t queue_idx, bool ready) -> void

auto	NotifyQueue (uint32_t queue_idx) -> void
	通知设备有新的可用缓冲区

auto	GetInterruptStatus () const -> uint32_t

auto	AckInterrupt (uint32_t ack_bits) -> void

auto	ReadConfigU8 (uint32_t offset) const -> uint8_t
	读取配置空间 8 位值

auto	ReadConfigU16 (uint32_t offset) const -> uint16_t
	读取配置空间 16 位值

auto	ReadConfigU32 (uint32_t offset) const -> uint32_t
	读取配置空间 32 位值

auto	ReadConfigU64 (uint32_t offset) const -> uint64_t
	读取配置空间 64 位值

auto	GetConfigGeneration () const -> uint32_t

构造/析构函数
	MmioTransport (MmioTransport &&other) noexcept

auto	operator= (MmioTransport &&) noexcept -> MmioTransport &=delete

	MmioTransport (const MmioTransport &)=delete

auto	operator= (const MmioTransport &) -> MmioTransport &=delete

Public Member Functions inherited from virtio::Transport
auto	Reset (this auto &&self) -> void
	重置设备

auto	NeedsReset (this auto const &self) -> bool
	检查设备是否需要重置

auto	IsActive (this auto const &self) -> bool
	检查设备是否已激活（DRIVER_OK 已设置）

auto	AcknowledgeInterrupt (this auto &&self) -> void
	确认并清除设备中断

Private Attributes
MmioAccessor	mmio_
	MMIO 寄存器访问器

bool	is_valid_
	设备是否成功初始化

uint32_t	device_id_
	设备 ID（缓存以避免重复读取）

uint32_t	vendor_id_
	供应商 ID（缓存以避免重复读取）

Additional Inherited Members
Protected Member Functions inherited from virtio::Transport
	Transport ()=default

	~Transport ()=default

	Transport (Transport &&) noexcept=default

auto	operator= (Transport &&) noexcept -> Transport &=default

	Transport (const Transport &)=delete

auto	operator= (const Transport &) -> Transport &=delete

Detailed Description

Virtio MMIO 传输层

MMIO virtio 设备通过一组内存映射的控制寄存器和设备特定配置空间进行访问。所有寄存器值采用小端格式组织。

仅支持 Modern VirtIO (v2, virtio 1.0+)。

寄存器布局包括：

魔数（MagicValue）: 0x74726976
版本号（Version）: 0x2（modern）
设备/供应商 ID
特性位配置
队列配置
中断状态与确认
设备状态
共享内存区域（可选，需要相应特性支持）
队列重置（可选，需要 VIRTIO_F_RING_RESET 特性）
设备特定配置空间（从 0x100 开始）

See also: virtio-v1.2#4.2 Virtio Over MMIO

Definition at line 61 of file mmio.hpp.

Member Enumeration Documentation

◆ MmioReg

enum class virtio::MmioTransport::MmioReg : size_t

strong

MMIO 寄存器偏移量

See also: virtio-v1.2#4.2.2 MMIO Device Register Layout

Enumerator
kMagicValue
kVersion
kDeviceId
kVendorId
kDeviceFeatures
kDeviceFeaturesSel
kDriverFeatures
kDriverFeaturesSel
kQueueSel
kQueueNumMax
kQueueNum
kQueueReady
kQueueNotify
kInterruptStatus
kInterruptAck
kStatus
kQueueDescLow
kQueueDescHigh
kQueueDriverLow
kQueueDriverHigh
kQueueDeviceLow
kQueueDeviceHigh
kShmSel
kShmLenLow
kShmLenHigh
kShmBaseLow
kShmBaseHigh
kQueueReset
kConfigGeneration
kConfig

Definition at line 67 of file mmio.hpp.

                     : size_t {
    kMagicValue = 0x000,
    kVersion = 0x004,
    kDeviceId = 0x008,
    kVendorId = 0x00C,
    kDeviceFeatures = 0x010,
    kDeviceFeaturesSel = 0x014,
    // 0x018 ~ 0x01F: reserved
    kDriverFeatures = 0x020,
    kDriverFeaturesSel = 0x024,
    // 0x028 ~ 0x02F: reserved
    kQueueSel = 0x030,
    kQueueNumMax = 0x034,
    kQueueNum = 0x038,
    // 0x03C ~ 0x03F: reserved
    // 0x040 ~ 0x043: reserved
    kQueueReady = 0x044,
    // 0x048 ~ 0x04F: reserved
    kQueueNotify = 0x050,
    // 0x054 ~ 0x05F: reserved
    kInterruptStatus = 0x060,
    kInterruptAck = 0x064,
    // 0x068 ~ 0x06F: reserved
    kStatus = 0x070,
    // 0x074 ~ 0x07F: reserved
    kQueueDescLow = 0x080,
    kQueueDescHigh = 0x084,
    // 0x088 ~ 0x08F: reserved
    kQueueDriverLow = 0x090,
    kQueueDriverHigh = 0x094,
    // 0x098 ~ 0x09F: reserved
    kQueueDeviceLow = 0x0A0,
    kQueueDeviceHigh = 0x0A4,
    // 0x0A8 ~ 0x0AB: reserved
    kShmSel = 0x0AC,
    kShmLenLow = 0x0B0,
    kShmLenHigh = 0x0B4,
    kShmBaseLow = 0x0B8,
    kShmBaseHigh = 0x0BC,
    kQueueReset = 0x0C0,
    // 0x0C4 ~ 0x0FB: reserved
    kConfigGeneration = 0x0FC,
    kConfig = 0x100,
  };

Constructor & Destructor Documentation

◆ MmioTransport() [1/3]

virtio::MmioTransport::MmioTransport ( uint64_t base )

inlineexplicit

构造函数

在构造时完成以下初始化：

验证 MMIO 魔数和版本号
检查设备是否存在（Device ID != 0）
执行设备重置
缓存设备 ID 和 Vendor ID

Parameters

base	MMIO 寄存器基地址

Postcondition: 构造完成后应调用 IsValid() 检查初始化是否成功

See also: virtio-v1.2#4.2.2 MMIO Device Register Layout

Definition at line 126 of file mmio.hpp.

      : mmio_(base), is_valid_(false), device_id_(0), vendor_id_(0) {
    if (base == 0) {
      return;
    }
 
    auto magic = mmio_.Read<uint32_t>(std::to_underlying(MmioReg::kMagicValue));
    if (magic != kMmioMagicValue) {
      return;
    }
 
    auto version = mmio_.Read<uint32_t>(std::to_underlying(MmioReg::kVersion));
    if (version != kMmioVersionModern) {
      return;
    }
 
    device_id_ = mmio_.Read<uint32_t>(std::to_underlying(MmioReg::kDeviceId));
    if (device_id_ == 0) {
      return;
    }
 
    vendor_id_ = mmio_.Read<uint32_t>(std::to_underlying(MmioReg::kVendorId));
    this->Reset();
    is_valid_ = true;
  }

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◆ MmioTransport() [2/3]

virtio::MmioTransport::MmioTransport ( MmioTransport && other )

inlinenoexcept

Definition at line 159 of file mmio.hpp.

      : Transport(std::move(other)),
        mmio_(other.mmio_),
        is_valid_(other.is_valid_),
        device_id_(other.device_id_),
        vendor_id_(other.vendor_id_) {
    other.is_valid_ = false;
  }

◆ MmioTransport() [3/3]

virtio::MmioTransport::MmioTransport ( const MmioTransport & )

delete

Member Function Documentation

◆ AckInterrupt()

auto virtio::MmioTransport::AckInterrupt ( uint32_t ack_bits ) -> void

inline

Definition at line 302 of file mmio.hpp.

                                               {
    mmio_.Write<uint32_t>(std::to_underlying(MmioReg::kInterruptAck), ack_bits);
  }

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◆ GetConfigGeneration()

auto virtio::MmioTransport::GetConfigGeneration ( ) const -> uint32_t

inline

Definition at line 370 of file mmio.hpp.

                                                             {
    return mmio_.Read<uint32_t>(std::to_underlying(MmioReg::kConfigGeneration));
  }

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◆ GetDeviceFeatures()

auto virtio::MmioTransport::GetDeviceFeatures ( ) -> uint64_t

inline

读取 64 位设备特性

需要分两次 32 位读取（低 32 位和高 32 位）。涉及硬件寄存器写入，因此不能声明为 const。

Returns: 设备支持的 64 位特性位

See also: virtio-v1.2#4.2.2.1

Definition at line 193 of file mmio.hpp.

                                                     {
    mmio_.Write<uint32_t>(std::to_underlying(MmioReg::kDeviceFeaturesSel), 0);
    uint64_t lo =
        mmio_.Read<uint32_t>(std::to_underlying(MmioReg::kDeviceFeatures));
 
    mmio_.Write<uint32_t>(std::to_underlying(MmioReg::kDeviceFeaturesSel), 1);
    uint64_t hi =
        mmio_.Read<uint32_t>(std::to_underlying(MmioReg::kDeviceFeatures));
 
    return (hi << 32) | lo;
  }

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◆ GetDeviceId()

auto virtio::MmioTransport::GetDeviceId ( ) const -> uint32_t

inline

Definition at line 172 of file mmio.hpp.

172{ return device_id_; }

◆ GetInterruptStatus()

auto virtio::MmioTransport::GetInterruptStatus ( ) const -> uint32_t

inline

Definition at line 298 of file mmio.hpp.

                                                            {
    return mmio_.Read<uint32_t>(std::to_underlying(MmioReg::kInterruptStatus));
  }

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◆ GetQueueNumMax()

auto virtio::MmioTransport::GetQueueNumMax ( uint32_t queue_idx ) -> uint32_t

inline

获取队列最大容量

涉及硬件寄存器写入，因此不能声明为 const。

Parameters

queue_idx 队列索引

Returns: 队列最大大小

See also: virtio-v1.2#4.2.3.2

Definition at line 230 of file mmio.hpp.

                                                                    {
    mmio_.Write<uint32_t>(std::to_underlying(MmioReg::kQueueSel), queue_idx);
    return mmio_.Read<uint32_t>(std::to_underlying(MmioReg::kQueueNumMax));
  }

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◆ GetQueueReady()

auto virtio::MmioTransport::GetQueueReady ( uint32_t queue_idx ) -> bool

inline

Definition at line 282 of file mmio.hpp.

                                                               {
    mmio_.Write<uint32_t>(std::to_underlying(MmioReg::kQueueSel), queue_idx);
    return mmio_.Read<uint32_t>(std::to_underlying(MmioReg::kQueueReady)) != 0;
  }

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◆ GetStatus()

auto virtio::MmioTransport::GetStatus ( ) const -> uint32_t

inline

Definition at line 176 of file mmio.hpp.

                                                   {
    return mmio_.Read<uint32_t>(std::to_underlying(MmioReg::kStatus));
  }

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◆ GetVendorId()

auto virtio::MmioTransport::GetVendorId ( ) const -> uint32_t

inline

Definition at line 174 of file mmio.hpp.

174{ return vendor_id_; }

◆ IsValid()

auto virtio::MmioTransport::IsValid ( ) const -> bool

inline

检查设备是否成功初始化

Definition at line 155 of file mmio.hpp.

155{ return is_valid_; }

◆ NotifyQueue()

auto virtio::MmioTransport::NotifyQueue ( uint32_t queue_idx ) -> void

inline

通知设备有新的可用缓冲区

Definition at line 294 of file mmio.hpp.

                                               {
    mmio_.Write<uint32_t>(std::to_underlying(MmioReg::kQueueNotify), queue_idx);
  }

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◆ operator=() [1/2]

auto virtio::MmioTransport::operator= ( const MmioTransport & ) -> MmioTransport &=delete

delete

◆ operator=() [2/2]

auto virtio::MmioTransport::operator= ( MmioTransport && ) -> MmioTransport &=delete

deletenoexcept

◆ ReadConfigU16()

auto virtio::MmioTransport::ReadConfigU16 ( uint32_t offset ) const -> uint16_t

inline

读取配置空间 16 位值

Parameters

offset 相对于配置空间起始的偏移量

Definition at line 321 of file mmio.hpp.

                                                                      {
    return mmio_.Read<uint16_t>(std::to_underlying(MmioReg::kConfig) + offset);
  }

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◆ ReadConfigU32()

auto virtio::MmioTransport::ReadConfigU32 ( uint32_t offset ) const -> uint32_t

inline

读取配置空间 32 位值

Parameters

offset 相对于配置空间起始的偏移量

Definition at line 330 of file mmio.hpp.

                                                                      {
    return mmio_.Read<uint32_t>(std::to_underlying(MmioReg::kConfig) + offset);
  }

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◆ ReadConfigU64()

auto virtio::MmioTransport::ReadConfigU64 ( uint32_t offset ) const -> uint64_t

inline

读取配置空间 64 位值

使用 generation counter 机制保证读取的 64 位配置数据一致性：

读取 ConfigGeneration
读取配置数据
再次读取 ConfigGeneration
如果两次 generation 不同，说明配置在读取过程中被修改，需要重试

Parameters

offset 相对于配置空间起始的偏移量

Returns: 64 位配置值（保证一致性）

See also: virtio-v1.2#2.5.1 Driver Requirements: Device Configuration Space; virtio-v1.2#4.2.2 MMIO Device Register Layout (ConfigGeneration)

Definition at line 348 of file mmio.hpp.

                                                                      {
    uint32_t gen1;
    uint32_t gen2;
    uint64_t value;
 
    static constexpr uint32_t kMaxConfigRetries = 1000;
    uint32_t retries = 0;
    do {
      gen1 = GetConfigGeneration();
 
      auto* ptr = reinterpret_cast<volatile uint32_t*>(
          mmio_.base + std::to_underlying(MmioReg::kConfig) + offset);
      uint64_t lo = ptr[0];
      uint64_t hi = ptr[1];
      value = (hi << 32) | lo;
 
      gen2 = GetConfigGeneration();
    } while (gen1 != gen2 && ++retries < kMaxConfigRetries);
 
    return value;
  }

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◆ ReadConfigU8()

auto virtio::MmioTransport::ReadConfigU8 ( uint32_t offset ) const -> uint8_t

inline

读取配置空间 8 位值

Parameters

offset 相对于配置空间起始的偏移量

See also: virtio-v1.2#4.2.2.2

Definition at line 312 of file mmio.hpp.

                                                                    {
    return mmio_.Read<uint8_t>(std::to_underlying(MmioReg::kConfig) + offset);
  }

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◆ SetDriverFeatures()

auto virtio::MmioTransport::SetDriverFeatures ( uint64_t features ) -> void

inline

写入 64 位驱动特性

Parameters

features 驱动程序接受的特性位

See also: virtio-v1.2#4.2.2.1

Definition at line 211 of file mmio.hpp.

                                                    {
    mmio_.Write<uint32_t>(std::to_underlying(MmioReg::kDriverFeaturesSel), 0);
    mmio_.Write<uint32_t>(std::to_underlying(MmioReg::kDriverFeatures),
                          static_cast<uint32_t>(features));
 
    mmio_.Write<uint32_t>(std::to_underlying(MmioReg::kDriverFeaturesSel), 1);
    mmio_.Write<uint32_t>(std::to_underlying(MmioReg::kDriverFeatures),
                          static_cast<uint32_t>(features >> 32));
  }

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◆ SetQueueAvail()

auto virtio::MmioTransport::SetQueueAvail	(	uint32_t	queue_idx,
		uint64_t	addr
	)		-> void

inline

设置 Available Ring 物理地址

Parameters

queue_idx	队列索引
addr	Available Ring 的 64 位物理地址

Definition at line 260 of file mmio.hpp.

                                                                {
    mmio_.Write<uint32_t>(std::to_underlying(MmioReg::kQueueSel), queue_idx);
    mmio_.Write<uint32_t>(std::to_underlying(MmioReg::kQueueDriverLow),
                          static_cast<uint32_t>(addr));
    mmio_.Write<uint32_t>(std::to_underlying(MmioReg::kQueueDriverHigh),
                          static_cast<uint32_t>(addr >> 32));
  }

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◆ SetQueueDesc()

auto virtio::MmioTransport::SetQueueDesc	(	uint32_t	queue_idx,
		uint64_t	addr
	)		-> void

inline

设置描述符表物理地址

Parameters

queue_idx	队列索引
addr	描述符表的 64 位物理地址

Definition at line 246 of file mmio.hpp.

                                                               {
    mmio_.Write<uint32_t>(std::to_underlying(MmioReg::kQueueSel), queue_idx);
    mmio_.Write<uint32_t>(std::to_underlying(MmioReg::kQueueDescLow),
                          static_cast<uint32_t>(addr));
    mmio_.Write<uint32_t>(std::to_underlying(MmioReg::kQueueDescHigh),
                          static_cast<uint32_t>(addr >> 32));
  }

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◆ SetQueueNum()

auto virtio::MmioTransport::SetQueueNum	(	uint32_t	queue_idx,
		uint32_t	num
	)		-> void

inline

Definition at line 235 of file mmio.hpp.

                                                             {
    mmio_.Write<uint32_t>(std::to_underlying(MmioReg::kQueueSel), queue_idx);
    mmio_.Write<uint32_t>(std::to_underlying(MmioReg::kQueueNum), num);
  }

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◆ SetQueueReady()

auto virtio::MmioTransport::SetQueueReady	(	uint32_t	queue_idx,
		bool	ready
	)		-> void

inline

Definition at line 287 of file mmio.hpp.

                                                             {
    mmio_.Write<uint32_t>(std::to_underlying(MmioReg::kQueueSel), queue_idx);
    mmio_.Write<uint32_t>(std::to_underlying(MmioReg::kQueueReady),
                          ready ? 1 : 0);
  }

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◆ SetQueueUsed()

auto virtio::MmioTransport::SetQueueUsed	(	uint32_t	queue_idx,
		uint64_t	addr
	)		-> void

inline

设置 Used Ring 物理地址

Parameters

queue_idx	队列索引
addr	Used Ring 的 64 位物理地址

Definition at line 274 of file mmio.hpp.

                                                               {
    mmio_.Write<uint32_t>(std::to_underlying(MmioReg::kQueueSel), queue_idx);
    mmio_.Write<uint32_t>(std::to_underlying(MmioReg::kQueueDeviceLow),
                          static_cast<uint32_t>(addr));
    mmio_.Write<uint32_t>(std::to_underlying(MmioReg::kQueueDeviceHigh),
                          static_cast<uint32_t>(addr >> 32));
  }

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◆ SetStatus()

auto virtio::MmioTransport::SetStatus ( uint32_t status ) -> void

inline

Definition at line 180 of file mmio.hpp.

                                          {
    mmio_.Write<uint32_t>(std::to_underlying(MmioReg::kStatus), status);
  }

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Member Data Documentation

◆ device_id_

uint32_t virtio::MmioTransport::device_id_

private

设备 ID（缓存以避免重复读取）

Definition at line 382 of file mmio.hpp.

◆ is_valid_

bool virtio::MmioTransport::is_valid_

private

设备是否成功初始化

Definition at line 379 of file mmio.hpp.

◆ mmio_

MmioAccessor virtio::MmioTransport::mmio_

private

MMIO 寄存器访问器

Definition at line 376 of file mmio.hpp.

◆ vendor_id_

uint32_t virtio::MmioTransport::vendor_id_

private

供应商 ID（缓存以避免重复读取）

Definition at line 385 of file mmio.hpp.

The documentation for this class was generated from the following file:

/workspaces/SimpleKernel/src/device/virtio/transport/mmio.hpp

Public Types

Public Member Functions

Private Attributes

Additional Inherited Members

Detailed Description

Member Enumeration Documentation

◆ MmioReg

Constructor & Destructor Documentation

◆ MmioTransport() [1/3]

◆ MmioTransport() [2/3]

◆ MmioTransport() [3/3]

Member Function Documentation

◆ AckInterrupt()

◆ GetConfigGeneration()

◆ GetDeviceFeatures()

◆ GetDeviceId()

◆ GetInterruptStatus()

◆ GetQueueNumMax()

◆ GetQueueReady()

◆ GetStatus()

◆ GetVendorId()

◆ IsValid()

◆ NotifyQueue()

◆ operator=() [1/2]

◆ operator=() [2/2]

◆ ReadConfigU16()

◆ ReadConfigU32()

◆ ReadConfigU64()

◆ ReadConfigU8()

◆ SetDriverFeatures()

◆ SetQueueAvail()

◆ SetQueueDesc()

◆ SetQueueNum()

◆ SetQueueReady()

◆ SetQueueUsed()

◆ SetStatus()

Member Data Documentation

◆ device_id_

◆ is_valid_

◆ mmio_

◆ vendor_id_