gem5  v20.1.0.0
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VirtIODeviceBase Class Reference

Base class for all VirtIO-based devices. More...

#include <base.hh>

Inheritance diagram for VirtIODeviceBase:
SimObject EventManager Serializable Drainable Stats::Group VirtIO9PBase VirtIOBlock VirtIOConsole VirtIODummyDevice VirtIO9PProxy VirtIO9PDiod VirtIO9PSocket

Public Types

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

 BitUnion8 (DeviceStatus) Bitfield< 7 > failed
 
 EndBitUnion (DeviceStatus) typedef VirtIODeviceBaseParams Params
 
 VirtIODeviceBase (Params *params, DeviceId id, size_t config_size, FeatureBits features)
 
virtual ~VirtIODeviceBase ()
 
SimObject Interfaces
void serialize (CheckpointOut &cp) const override
 Serialize an object. More...
 
void unserialize (CheckpointIn &cp) override
 Unserialize an object. More...
 
Optional VirtIO Interfaces
virtual void readConfig (PacketPtr pkt, Addr cfgOffset)
 Read from the configuration space of a device. 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...
 
- Public Member Functions inherited from SimObject
const Paramsparams () 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...
 
ProbeManagergetProbeManager ()
 Get the probe manager for this object. More...
 
virtual PortgetPort (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
EventQueueeventQueue () 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 InforesolveStat (std::string name) const
 Resolve a stat by its name within this group. More...
 
 Group ()=delete
 
 Group (const Group &)=delete
 
Groupoperator= (const Group &)=delete
 

Public Attributes

Bitfield< 2 > driver_ok
 
Bitfield< 1 > driver
 
Bitfield< 0 > acknowledge
 

Private Member Functions

const VirtQueuegetCurrentQueue () const
 Convenience method to get the currently selected queue. More...
 
VirtQueuegetCurrentQueue ()
 Convenience method to get the currently selected queue. More...
 

Private Attributes

DeviceStatus _deviceStatus
 Status of the device. More...
 
QueueID _queueSelect
 Queue select register (set by guest) More...
 
std::vector< VirtQueue * > _queues
 List of virtual queues supported by this device. More...
 
std::function< void()> transKick
 Callbacks to kick the guest through the transport layer
More...
 

Device Model Interfaces

FeatureBits guestFeatures
 Feature set accepted by the guest. More...
 
void kick ()
 Inform the guest of available buffers. More...
 
void registerQueue (VirtQueue &queue)
 Register a new VirtQueue with the device model. More...
 

Device Model Helpers

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

VirtIO Transport Interfaces

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...
 
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...
 

Additional Inherited Members

- Static Public Member Functions inherited from SimObject
static void serializeAll (CheckpointOut &cp)
 Serialize all SimObjects in the system. More...
 
static SimObjectfind (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)
 
- 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 inherited from SimObject
const SimObjectParams * _params
 Cached copy of the object parameters. More...
 
- Protected Attributes inherited from EventManager
EventQueueeventq
 A pointer to this object's event queue. More...
 

Detailed Description

Base class for all VirtIO-based devices.

This class implements the functionality of the VirtIO 0.9.5 specification. This version of VirtIO is also known as "legacy" in the VirtIO 1.0 specification from OASIS.

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

Definition at line 558 of file base.hh.

Member Typedef Documentation

◆ DeviceId

typedef uint16_t VirtIODeviceBase::DeviceId

Device Type (sometimes known as subsystem ID)

Definition at line 570 of file base.hh.

◆ FeatureBits

Definition at line 562 of file base.hh.

◆ QueueID

typedef uint16_t VirtIODeviceBase::QueueID

Definition at line 561 of file base.hh.

◆ 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.

Definition at line 568 of file base.hh.

Constructor & Destructor Documentation

◆ VirtIODeviceBase()

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

Definition at line 325 of file base.cc.

◆ ~VirtIODeviceBase()

VirtIODeviceBase::~VirtIODeviceBase ( )
virtual

Definition at line 336 of file base.cc.

Member Function Documentation

◆ BitUnion8()

VirtIODeviceBase::BitUnion8 ( DeviceStatus  )

◆ EndBitUnion()

VirtIODeviceBase::EndBitUnion ( DeviceStatus  )

◆ getCurrentQueue() [1/2]

VirtQueue& VirtIODeviceBase::getCurrentQueue ( )
private

Convenience method to get the currently selected queue.

◆ getCurrentQueue() [2/2]

VirtQueue & VirtIODeviceBase::getCurrentQueue ( ) const
private

Convenience method to get the currently selected queue.

Definition at line 445 of file base.cc.

References _queues, _queueSelect, and panic.

Referenced by getQueueAddress(), getQueueSize(), and setQueueAddress().

◆ getDeviceStatus()

DeviceStatus VirtIODeviceBase::getDeviceStatus ( ) const
inline

Retrieve the device status.

Returns
Device status.

Definition at line 826 of file base.hh.

References _deviceStatus.

Referenced by PciVirtIO::read(), and MmioVirtIO::read().

◆ getGuestFeatures()

FeatureBits VirtIODeviceBase::getGuestFeatures ( ) const
inline

Get features accepted by the guest driver.

Returns
Currently active features.

Definition at line 841 of file base.hh.

References guestFeatures.

Referenced by PciVirtIO::read(), and MmioVirtIO::read().

◆ getQueueAddress()

uint32_t VirtIODeviceBase::getQueueAddress ( ) const

Get the host physical address of the currently active queue.

Note
The new address is specified in multiples of the page size (fixed to 4096 bytes in the standard). For example, if the address 10 is selected, the actual host physical address will be 40960.
See also
setQueueSelect
getQueueSelect
Returns
Address of the currently active queue (in pages).

Definition at line 469 of file base.cc.

References VirtQueue::ALIGN_BITS, and getCurrentQueue().

Referenced by PciVirtIO::read(), and MmioVirtIO::read().

◆ getQueueSelect()

QueueID VirtIODeviceBase::getQueueSelect ( ) const
inline

Get the currently active queue.

The transport interface works on a queue at a time. The currently active queue is decided by the value of the queue select field in a device.

Returns
The ID of the currently active queue.

Definition at line 771 of file base.hh.

References _queueSelect.

Referenced by PciVirtIO::read(), and MmioVirtIO::read().

◆ getQueueSize()

uint16_t VirtIODeviceBase::getQueueSize ( ) const
inline

Get the size (descriptors) of the currently active queue.

Returns
Size of the currently active queue in number of descriptors.

Definition at line 809 of file base.hh.

References getCurrentQueue(), and VirtQueue::getSize().

Referenced by PciVirtIO::read(), and MmioVirtIO::read().

◆ kick()

void VirtIODeviceBase::kick ( )
inlineprotected

Inform the guest of available buffers.

When a device model has finished processing incoming buffers (after onNotify has been called), it typically needs to inform the guest that there are new pending outgoing buffers. The method used to inform the guest is transport dependent, but is typically through an interrupt. Device models call this method to tell the transport interface to notify the guest.

Definition at line 609 of file base.hh.

References transKick.

Referenced by VirtIOBlock::RequestQueue::onNotifyDescriptor(), VirtIO9PBase::sendRMsg(), and VirtIOConsole::TermRecvQueue::trySend().

◆ onNotify()

void VirtIODeviceBase::onNotify ( QueueID  index)

Driver is requesting service.

This method is called by the underlying hardware interface (e.g., PciVirtIO or MmmioVirtIO) to notify a device of pending incoming descriptors.

Parameters
indexID of the queue with pending actions.

Definition at line 372 of file base.cc.

References _queues, DPRINTF, and panic.

Referenced by PciVirtIO::write(), and MmioVirtIO::write().

◆ readConfig()

void VirtIODeviceBase::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
pktRead request packet.
cfgOffsetOffset into the device's configuration space.

Reimplemented in VirtIO9PBase, VirtIOBlock, and VirtIOConsole.

Definition at line 408 of file base.cc.

References panic.

Referenced by MmioVirtIO::read(), and PciVirtIO::read().

◆ readConfigBlob()

void VirtIODeviceBase::readConfigBlob ( PacketPtr  pkt,
Addr  cfgOffset,
const uint8_t *  cfg 
)
protected

Read configuration data from a device structure.

Parameters
pktRead request packet.
cfgOffsetOffset into the device's configuration space.
cfgDevice configuration

Definition at line 420 of file base.cc.

References configSize, Packet::getSize(), Packet::makeResponse(), panic, and Packet::setData().

Referenced by VirtIOConsole::readConfig(), VirtIOBlock::readConfig(), and VirtIO9PBase::readConfig().

◆ registerKickCallback()

void VirtIODeviceBase::registerKickCallback ( const std::function< void()> &  callback)
inline

Register a callback to kick the guest through the transport interface.

Parameters
callbackCallback into transport interface.

Definition at line 733 of file base.hh.

References transKick.

Referenced by MmioVirtIO::MmioVirtIO(), and PciVirtIO::PciVirtIO().

◆ registerQueue()

void VirtIODeviceBase::registerQueue ( VirtQueue queue)
protected

Register a new VirtQueue with the device model.

Devices typically register at least one VirtQueue to use for communication with the guest. This must be done from the constructor since the number of queues are assumed to be constant throughout the lifetime of the device.

Warning
This method may only be called from the device model constructor.

Definition at line 477 of file base.cc.

References _queues.

Referenced by VirtIO9PBase::VirtIO9PBase(), VirtIOBlock::VirtIOBlock(), and VirtIOConsole::VirtIOConsole().

◆ reset()

void VirtIODeviceBase::reset ( )
virtual

Driver-request device reset.

The device driver may reset a device by writing zero to the device status register (using setDeviceStatus()), which causes this method to be called. Device models overriding this method must ensure that the reset method of the base class is called when the device is reset.

Note
Always call the reset method of the base class from device-specific reset methods.

Definition at line 361 of file base.cc.

References _deviceStatus, _queues, _queueSelect, guestFeatures, and ArmISA::i.

Referenced by setDeviceStatus().

◆ serialize()

void VirtIODeviceBase::serialize ( CheckpointOut cp) const
overridevirtual

Serialize an object.

Output an object's state into the current checkpoint section.

Parameters
cpCheckpoint state

Implements Serializable.

Reimplemented in VirtIO9PProxy.

Definition at line 341 of file base.cc.

References _deviceStatus, _queues, _queueSelect, csprintf(), guestFeatures, ArmISA::i, SERIALIZE_SCALAR, and Serializable::serializeSection().

Referenced by VirtIO9PProxy::serialize().

◆ setDeviceStatus()

void VirtIODeviceBase::setDeviceStatus ( DeviceStatus  status)

Update device status and optionally reset device.

The special device status of 0 is used to reset the device by calling reset().

Parameters
statusNew device status.

Definition at line 398 of file base.cc.

References _deviceStatus, DPRINTF, reset(), and ArmISA::status.

Referenced by PciVirtIO::write(), and MmioVirtIO::write().

◆ setGuestFeatures()

void VirtIODeviceBase::setGuestFeatures ( FeatureBits  features)

Set feature bits accepted by the guest driver.

This enables a subset of the features offered by the device model through the getGuestFeatures() interface.

Definition at line 384 of file base.cc.

References deviceFeatures, DPRINTF, guestFeatures, and panic.

Referenced by PciVirtIO::write(), and MmioVirtIO::write().

◆ setQueueAddress()

void VirtIODeviceBase::setQueueAddress ( uint32_t  address)

Change the host physical address of the currently active queue.

Note
The new address is specified in multiples of the page size (fixed to 4096 bytes in the standard). For example, if the address 10 is selected, the actual host physical address will be 40960.
See also
setQueueSelect
getQueueSelect
Parameters
addressNew address of the currently active queue (in pages).

Definition at line 463 of file base.cc.

References VirtQueue::ALIGN_SIZE, getCurrentQueue(), and VirtQueue::setAddress().

Referenced by PciVirtIO::write(), and MmioVirtIO::write().

◆ setQueueSelect()

void VirtIODeviceBase::setQueueSelect ( QueueID  idx)
inline

Change currently active queue.

The transport interface works on a queue at a time. The currently active queue is decided by the value of the queue select field in a device.

Parameters
idxID of the queue to select.

Definition at line 761 of file base.hh.

References _queueSelect.

Referenced by PciVirtIO::write(), and MmioVirtIO::write().

◆ unserialize()

void VirtIODeviceBase::unserialize ( CheckpointIn cp)
overridevirtual

Unserialize an object.

Read an object's state from the current checkpoint section.

Parameters
cpCheckpoint state

Implements Serializable.

Reimplemented in VirtIO9PProxy.

Definition at line 351 of file base.cc.

References _deviceStatus, _queues, _queueSelect, csprintf(), guestFeatures, ArmISA::i, UNSERIALIZE_SCALAR, and Serializable::unserializeSection().

Referenced by VirtIO9PProxy::unserialize().

◆ writeConfig()

void VirtIODeviceBase::writeConfig ( PacketPtr  pkt,
Addr  cfgOffset 
)
virtual

Write to the configuration space of a device.

This method is called by the transport interface to write data into 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
pktWrite request packet.
cfgOffsetOffset into the device's configuration space.

Definition at line 414 of file base.cc.

References panic.

Referenced by MmioVirtIO::write(), and PciVirtIO::write().

◆ writeConfigBlob()

void VirtIODeviceBase::writeConfigBlob ( PacketPtr  pkt,
Addr  cfgOffset,
uint8_t *  cfg 
)
protected

Write configuration data to a device structure.

Parameters
pktWrite request packet.
cfgOffsetOffset into the device's configuration space.
cfgDevice configuration

Definition at line 432 of file base.cc.

References configSize, Packet::getSize(), Packet::makeResponse(), panic, and Packet::writeData().

Member Data Documentation

◆ _deviceStatus

DeviceStatus VirtIODeviceBase::_deviceStatus
private

Status of the device.

See also
getDeviceStatus
setDeviceStatus

Definition at line 865 of file base.hh.

Referenced by getDeviceStatus(), reset(), serialize(), setDeviceStatus(), and unserialize().

◆ _queues

std::vector<VirtQueue *> VirtIODeviceBase::_queues
private

List of virtual queues supported by this device.

Definition at line 871 of file base.hh.

Referenced by getCurrentQueue(), onNotify(), registerQueue(), reset(), serialize(), and unserialize().

◆ _queueSelect

QueueID VirtIODeviceBase::_queueSelect
private

Queue select register (set by guest)

Definition at line 868 of file base.hh.

Referenced by getCurrentQueue(), getQueueSelect(), reset(), serialize(), setQueueSelect(), and unserialize().

◆ acknowledge

Bitfield<0> VirtIODeviceBase::acknowledge

Definition at line 576 of file base.hh.

◆ byteOrder

ByteOrder VirtIODeviceBase::byteOrder
protected

The byte order of the queues, descriptors, etc.

Definition at line 718 of file base.hh.

Referenced by VirtIOConsole::readConfig(), VirtIOBlock::readConfig(), and VirtIO9PBase::VirtIO9PBase().

◆ configSize

const size_t VirtIODeviceBase::configSize

Size of the device's configuration space.

Definition at line 847 of file base.hh.

Referenced by PciVirtIO::PciVirtIO(), readConfigBlob(), VirtIO9PBase::VirtIO9PBase(), and writeConfigBlob().

◆ deviceFeatures

const FeatureBits VirtIODeviceBase::deviceFeatures

Feature set offered by the device.

Definition at line 850 of file base.hh.

Referenced by PciVirtIO::read(), MmioVirtIO::read(), and setGuestFeatures().

◆ deviceId

const DeviceId VirtIODeviceBase::deviceId

Device ID (sometimes known as subsystem ID)

Definition at line 844 of file base.hh.

Referenced by PciVirtIO::PciVirtIO(), and MmioVirtIO::read().

◆ driver

Bitfield<1> VirtIODeviceBase::driver

Definition at line 575 of file base.hh.

◆ driver_ok

Bitfield<2> VirtIODeviceBase::driver_ok

Definition at line 574 of file base.hh.

◆ guestFeatures

FeatureBits VirtIODeviceBase::guestFeatures
protected

Feature set accepted by the guest.

When the guest starts the driver for the device, it starts by negotiating features. The device first offers a set of features (see deviceFeatures), the driver then notifies the device of which features it accepted. The base class will automatically accept any feature set that is a subset of the features offered by the device.

Definition at line 639 of file base.hh.

Referenced by getGuestFeatures(), reset(), serialize(), setGuestFeatures(), and unserialize().

◆ transKick

std::function<void()> VirtIODeviceBase::transKick
private

Callbacks to kick the guest through the transport layer

Definition at line 874 of file base.hh.

Referenced by kick(), and registerKickCallback().


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

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