VirtIO block device. More...

#include <block.hh>

Inheritance diagram for VirtIOBlock:

Classes
struct	BlkRequest
	VirtIO block device request as sent by guest. More...

struct	Config
	Block device configuration structure. More...

class	RequestQueue
	Virtqueue for disk requests. More...

Public Types
typedef VirtIOBlockParams	Params

Public Types inherited from VirtIODeviceBase
typedef uint16_t	QueueID

typedef uint32_t	FeatureBits

typedef uint16_t	VirtAddress
	This is a VirtQueue address as exposed through the low-level interface. The address needs to be multiplied by the page size (seems to be hardcoded to 4096 in the spec) to get the real physical address. More...

typedef uint16_t	DeviceId
	Device Type (sometimes known as subsystem ID) More...

Public Types inherited from SimObject
typedef SimObjectParams	Params

Public Member Functions
	VirtIOBlock (Params *params)

virtual	~VirtIOBlock ()

void	readConfig (PacketPtr pkt, Addr cfgOffset)
	Read from the configuration space of a device. More...

Public Member Functions inherited from VirtIODeviceBase
	BitUnion8 (DeviceStatus) Bitfield< 7 > failed

	EndBitUnion (DeviceStatus) typedef VirtIODeviceBaseParams Params

	VirtIODeviceBase (Params *params, DeviceId id, size_t config_size, FeatureBits features)

virtual	~VirtIODeviceBase ()

void	serialize (CheckpointOut &cp) const override
	Serialize an object. More...

void	unserialize (CheckpointIn &cp) override
	Unserialize an object. More...

virtual void	writeConfig (PacketPtr pkt, Addr cfgOffset)
	Write to the configuration space of a device. More...

virtual void	reset ()
	Driver-request device reset. More...

void	registerKickCallback (const std::function< void()> &callback)
	Register a callback to kick the guest through the transport interface. More...

void	onNotify (QueueID index)
	Driver is requesting service. More...

void	setQueueSelect (QueueID idx)
	Change currently active queue. More...

QueueID	getQueueSelect () const
	Get the currently active queue. More...

void	setQueueAddress (uint32_t address)
	Change the host physical address of the currently active queue. More...

uint32_t	getQueueAddress () const
	Get the host physical address of the currently active queue. More...

uint16_t	getQueueSize () const
	Get the size (descriptors) of the currently active queue. More...

void	setDeviceStatus (DeviceStatus status)
	Update device status and optionally reset device. More...

DeviceStatus	getDeviceStatus () const
	Retrieve the device status. More...

void	setGuestFeatures (FeatureBits features)
	Set feature bits accepted by the guest driver. More...

FeatureBits	getGuestFeatures () const
	Get features accepted by the guest driver. More...

Public Member Functions inherited from SimObject
const Params *	params () const

	SimObject (const Params *_params)

virtual	~SimObject ()

virtual const std::string	name () const

virtual void	init ()
	init() is called after all C++ SimObjects have been created and all ports are connected. More...

virtual void	loadState (CheckpointIn &cp)
	loadState() is called on each SimObject when restoring from a checkpoint. More...

virtual void	initState ()
	initState() is called on each SimObject when not restoring from a checkpoint. More...

virtual void	regProbePoints ()
	Register probe points for this object. More...

virtual void	regProbeListeners ()
	Register probe listeners for this object. More...

ProbeManager *	getProbeManager ()
	Get the probe manager for this object. More...

virtual Port &	getPort (const std::string &if_name, PortID idx=InvalidPortID)
	Get a port with a given name and index. More...

virtual void	startup ()
	startup() is the final initialization call before simulation. More...

DrainState	drain () override
	Provide a default implementation of the drain interface for objects that don't need draining. More...

virtual void	memWriteback ()
	Write back dirty buffers to memory using functional writes. More...

virtual void	memInvalidate ()
	Invalidate the contents of memory buffers. More...

void	serialize (CheckpointOut &cp) const override
	Serialize an object. More...

void	unserialize (CheckpointIn &cp) override
	Unserialize an object. More...

Public Member Functions inherited from EventManager
EventQueue *	eventQueue () const

void	schedule (Event &event, Tick when)

void	deschedule (Event &event)

void	reschedule (Event &event, Tick when, bool always=false)

void	schedule (Event *event, Tick when)

void	deschedule (Event *event)

void	reschedule (Event *event, Tick when, bool always=false)

void	wakeupEventQueue (Tick when=(Tick) -1)
	This function is not needed by the usual gem5 event loop but may be necessary in derived EventQueues which host gem5 on other schedulers. More...

void	setCurTick (Tick newVal)

	EventManager (EventManager &em)
	Event manger manages events in the event queue. More...

	EventManager (EventManager *em)

	EventManager (EventQueue *eq)

Public Member Functions inherited from Serializable
	Serializable ()

virtual	~Serializable ()

void	serializeSection (CheckpointOut &cp, const char *name) const
	Serialize an object into a new section. More...

void	serializeSection (CheckpointOut &cp, const std::string &name) const

void	unserializeSection (CheckpointIn &cp, const char *name)
	Unserialize an a child object. More...

void	unserializeSection (CheckpointIn &cp, const std::string &name)

Public Member Functions inherited from Drainable
DrainState	drainState () const
	Return the current drain state of an object. More...

virtual void	notifyFork ()
	Notify a child process of a fork. More...

Public Member Functions inherited from Stats::Group
	Group (Group parent, const char name=nullptr)
	Construct a new statistics group. More...

virtual	~Group ()

virtual void	regStats ()
	Callback to set stat parameters. More...

virtual void	resetStats ()
	Callback to reset stats. More...

virtual void	preDumpStats ()
	Callback before stats are dumped. More...

void	addStat (Stats::Info *info)
	Register a stat with this group. More...

const std::map< std::string, Group * > &	getStatGroups () const
	Get all child groups associated with this object. More...

const std::vector< Info * > &	getStats () const
	Get all stats associated with this object. More...

void	addStatGroup (const char name, Group block)
	Add a stat block as a child of this block. More...

const Info *	resolveStat (std::string name) const
	Resolve a stat by its name within this group. More...

	Group ()=delete

	Group (const Group &)=delete

Group &	operator= (const Group &)=delete

Protected Member Functions
Status	read (const BlkRequest &req, VirtDescriptor *desc_chain, size_t off_data, size_t size)
	Device read request. More...

Status	write (const BlkRequest &req, VirtDescriptor *desc_chain, size_t off_data, size_t size)
	Device write request. More...

Protected Member Functions inherited from VirtIODeviceBase
void	kick ()
	Inform the guest of available buffers. More...

void	registerQueue (VirtQueue &queue)
	Register a new VirtQueue with the device model. More...

void	readConfigBlob (PacketPtr pkt, Addr cfgOffset, const uint8_t *cfg)
	Read configuration data from a device structure. More...

void	writeConfigBlob (PacketPtr pkt, Addr cfgOffset, uint8_t *cfg)
	Write configuration data to a device structure. More...

Protected Member Functions inherited from Drainable
	Drainable ()

virtual	~Drainable ()

virtual void	drainResume ()
	Resume execution after a successful drain. More...

void	signalDrainDone () const
	Signal that an object is drained. More...

Protected Attributes
struct VirtIOBlock::Config	M5_ATTR_PACKED

Config	config

struct VirtIOBlock::BlkRequest	M5_ATTR_PACKED

RequestQueue	qRequests
	Device I/O request queue. More...

DiskImage &	image
	Image backing this device. More...

Protected Attributes inherited from VirtIODeviceBase
FeatureBits	guestFeatures
	Feature set accepted by the guest. More...

ByteOrder	byteOrder
	The byte order of the queues, descriptors, etc. More...

Protected Attributes inherited from SimObject
const SimObjectParams *	_params
	Cached copy of the object parameters. More...

Protected Attributes inherited from EventManager
EventQueue *	eventq
	A pointer to this object's event queue. More...

Static Protected Attributes
static const DeviceId	ID_BLOCK = 0x02

Feature bits
static const FeatureBits	F_SIZE_MAX = (1 << 1)

static const FeatureBits	F_SEG_MAX = (1 << 2)

static const FeatureBits	F_GEOMETRY = (1 << 4)

static const FeatureBits	F_RO = (1 << 5)

static const FeatureBits	F_BLK_SIZE = (1 << 6)

static const FeatureBits	F_TOPOLOGY = (1 << 10)

VirtIO block requests
typedef uint32_t	RequestType

static const RequestType	T_IN = 0
	Read request. More...

static const RequestType	T_OUT = 1
	Write request. More...

static const RequestType	T_FLUSH = 4
	Flush device buffers. More...

VirtIO block request status
typedef uint8_t	Status

static const Status	S_OK = 0
	Request succeeded. More...

static const Status	S_IOERR = 1
	Request failed due to a device error. More...

static const Status	S_UNSUPP = 2
	Request not supported. More...

Additional Inherited Members
Static Public Member Functions inherited from SimObject
static void	serializeAll (CheckpointOut &cp)
	Serialize all SimObjects in the system. More...

static SimObject *	find (const char *name)
	Find the SimObject with the given name and return a pointer to it. More...

Static Public Member Functions inherited from Serializable
static const std::string &	currentSection ()
	Gets the fully-qualified name of the active section. More...

static void	serializeAll (const std::string &cpt_dir)
	Serializes all the SimObjects. More...

static void	unserializeGlobals (CheckpointIn &cp)

Public Attributes inherited from VirtIODeviceBase
Bitfield< 2 >	driver_ok

Bitfield< 1 >	driver

Bitfield< 0 >	acknowledge

const DeviceId	deviceId
	Device ID (sometimes known as subsystem ID) More...

const size_t	configSize
	Size of the device's configuration space. More...

const FeatureBits	deviceFeatures
	Feature set offered by the device. More...

Detailed Description

VirtIO block device.

The block device uses the following queues:

Requests

A guest issues a request by creating a descriptor chain that starts with a BlkRequest. Immediately after the BlkRequest follows the data for the request. The data buffer(s) are either input or output descriptors depending on the request type. The last byte in the descriptor chain should always be writable by the host and contains the request status code (OK/Error).

The protocol supports asynchronous request completion by returning descriptor chains when they have been populated by the backing store. However, there is little point in doing so here.

See also: https://github.com/rustyrussell/virtio-spec; http://docs.oasis-open.org/virtio/virtio/v1.0/virtio-v1.0.html

Definition at line 66 of file block.hh.

Member Typedef Documentation

◆ Params

typedef VirtIOBlockParams VirtIOBlock::Params

Definition at line 69 of file block.hh.

◆ RequestType

typedef uint32_t VirtIOBlock::RequestType

protected

Definition at line 103 of file block.hh.

◆ Status

typedef uint8_t VirtIOBlock::Status

protected

Definition at line 115 of file block.hh.

Constructor & Destructor Documentation

◆ VirtIOBlock()

VirtIOBlock::VirtIOBlock ( Params * params )

Definition at line 44 of file block.cc.

References VirtIOBlock::Config::capacity, config, image, qRequests, VirtIODeviceBase::registerQueue(), and DiskImage::size().

◆ ~VirtIOBlock()

VirtIOBlock::~VirtIOBlock ( )

virtual

Definition at line 56 of file block.cc.

Member Function Documentation

◆ read()

VirtIOBlock::Status VirtIOBlock::read	(	const BlkRequest &	req,
		VirtDescriptor *	desc_chain,
		size_t	off_data,
		size_t	size
	)

protected

Device read request.

Parameters

req	Disk request from guest.
desc_chain	Request descriptor chain (from start of request)
off_data	Offset into the descriptor chain where data should be written.
size	Request data size.

Definition at line 70 of file block.cc.

References VirtDescriptor::chainWrite(), data, DPRINTF, image, ArmISA::offset, panic, DiskImage::read(), S_IOERR, S_OK, VirtIOBlock::BlkRequest::sector, SectorSize, and warn.

Referenced by VirtIOBlock::RequestQueue::onNotifyDescriptor().

◆ readConfig()

void VirtIOBlock::readConfig	(	PacketPtr	pkt,
		Addr	cfgOffset
	)

virtual

Read from the configuration space of a device.

This method is called by the transport interface to read data from a device model's configuration space. The device model should use the cfgOffset parameter as the offset into its configuration space.

Warning: The address in the packet should not be used to determine the offset into a device's configuration space.

Parameters

pkt	Read request packet.
cfgOffset	Offset into the device's configuration space.

Reimplemented from VirtIODeviceBase.

Definition at line 61 of file block.cc.

References VirtIODeviceBase::byteOrder, VirtIOBlock::Config::capacity, config, htog(), and VirtIODeviceBase::readConfigBlob().

◆ write()

VirtIOBlock::Status VirtIOBlock::write	(	const BlkRequest &	req,
		VirtDescriptor *	desc_chain,
		size_t	off_data,
		size_t	size
	)

protected

Device write request.

Parameters

req	Disk request from guest.
desc_chain	Request descriptor chain (from start of request)
off_data	Offset into the descriptor chain where data should be read.
size	Request data size.

Definition at line 96 of file block.cc.

References VirtDescriptor::chainRead(), data, DPRINTF, image, ArmISA::offset, panic, S_IOERR, S_OK, VirtIOBlock::BlkRequest::sector, SectorSize, warn, and DiskImage::write().

Referenced by VirtIOBlock::RequestQueue::onNotifyDescriptor().

Member Data Documentation

◆ config

Config VirtIOBlock::config

protected

Definition at line 87 of file block.hh.

Referenced by readConfig(), and VirtIOBlock().

◆ F_BLK_SIZE

const FeatureBits VirtIOBlock::F_BLK_SIZE = (1 << 6)

staticprotected

Definition at line 96 of file block.hh.

◆ F_GEOMETRY

const FeatureBits VirtIOBlock::F_GEOMETRY = (1 << 4)

staticprotected

Definition at line 94 of file block.hh.

◆ F_RO

const FeatureBits VirtIOBlock::F_RO = (1 << 5)

staticprotected

Definition at line 95 of file block.hh.

◆ F_SEG_MAX

const FeatureBits VirtIOBlock::F_SEG_MAX = (1 << 2)

staticprotected

Definition at line 93 of file block.hh.

◆ F_SIZE_MAX

const FeatureBits VirtIOBlock::F_SIZE_MAX = (1 << 1)

staticprotected

Definition at line 92 of file block.hh.

◆ F_TOPOLOGY

const FeatureBits VirtIOBlock::F_TOPOLOGY = (1 << 10)

staticprotected

Definition at line 97 of file block.hh.

◆ ID_BLOCK

const DeviceId VirtIOBlock::ID_BLOCK = 0x02

staticprotected

Definition at line 76 of file block.hh.

◆ image

DiskImage& VirtIOBlock::image

protected

Image backing this device.

Definition at line 181 of file block.hh.

Referenced by read(), VirtIOBlock(), and write().

◆ M5_ATTR_PACKED [1/2]

struct VirtIOBlock::Config VirtIOBlock::M5_ATTR_PACKED

protected

◆ M5_ATTR_PACKED [2/2]

struct VirtIOBlock::BlkRequest VirtIOBlock::M5_ATTR_PACKED

protected

◆ qRequests

RequestQueue VirtIOBlock::qRequests

protected

Device I/O request queue.

Definition at line 178 of file block.hh.

Referenced by VirtIOBlock().

◆ S_IOERR

const Status VirtIOBlock::S_IOERR = 1

staticprotected

Request failed due to a device error.

Definition at line 119 of file block.hh.

Referenced by read(), and write().

◆ S_OK

const Status VirtIOBlock::S_OK = 0

staticprotected

Request succeeded.

Definition at line 117 of file block.hh.

Referenced by VirtIOBlock::RequestQueue::onNotifyDescriptor(), read(), and write().

◆ S_UNSUPP

const Status VirtIOBlock::S_UNSUPP = 2

staticprotected

Request not supported.

Definition at line 121 of file block.hh.

Referenced by VirtIOBlock::RequestQueue::onNotifyDescriptor().

◆ T_FLUSH

const RequestType VirtIOBlock::T_FLUSH = 4

staticprotected

Flush device buffers.

Definition at line 109 of file block.hh.

Referenced by VirtIOBlock::RequestQueue::onNotifyDescriptor().

◆ T_IN

const RequestType VirtIOBlock::T_IN = 0

staticprotected

Read request.

Definition at line 105 of file block.hh.

Referenced by VirtIOBlock::RequestQueue::onNotifyDescriptor().

◆ T_OUT

const RequestType VirtIOBlock::T_OUT = 1

staticprotected

Write request.

Definition at line 107 of file block.hh.

Referenced by VirtIOBlock::RequestQueue::onNotifyDescriptor().

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

dev/virtio/block.hh
dev/virtio/block.cc

Classes

Public Types

Public Member Functions

Protected Member Functions

Protected Attributes

Static Protected Attributes

VirtIO block requests

VirtIO block request status

Additional Inherited Members

Detailed Description

Member Typedef Documentation

◆ Params

◆ RequestType

◆ Status

Constructor & Destructor Documentation

◆ VirtIOBlock()

◆ ~VirtIOBlock()

Member Function Documentation

◆ read()

◆ readConfig()

◆ write()

Member Data Documentation

◆ config

◆ F_BLK_SIZE

◆ F_GEOMETRY

◆ F_RO

◆ F_SEG_MAX

◆ F_SIZE_MAX

◆ F_TOPOLOGY

◆ ID_BLOCK

◆ image

◆ M5_ATTR_PACKED [1/2]

◆ M5_ATTR_PACKED [2/2]

◆ qRequests

◆ S_IOERR

◆ S_OK

◆ S_UNSUPP

◆ T_FLUSH

◆ T_IN

◆ T_OUT