Base wrapper around a virtqueue. More...

#include <base.hh>

Inheritance diagram for VirtQueue:

Classes
class	VirtRing
	VirtIO ring buffer wrapper. More...

Public Member Functions
virtual	~VirtQueue ()

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

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

Low-level Device Interface
void	setAddress (Addr address)
	Set the base address of this queue. More...

Addr	getAddress () const
	Get the guest physical address of this queue. More...

uint16_t	getSize () const
	Get the number of descriptors available in this queue. More...

VirtDescriptor *	getDescriptor (VirtDescriptor::Index index)
	Get a pointer to a specific descriptor in the queue. More...

Device Model Interfaces
VirtDescriptor *	consumeDescriptor ()
	Get an incoming descriptor chain from the queue. More...

void	produceDescriptor (VirtDescriptor *desc, uint32_t len)
	Send a descriptor chain to the guest. More...

Device Model Callbacks
virtual void	onNotify ()
	Notify queue of pending events. More...

virtual void	onNotifyDescriptor (VirtDescriptor *desc)
	Notify queue of pending incoming descriptor. More...

Debug interfaces
void	dump () const
	Dump the contents of a queue. More...

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)

Static Public Attributes

static const unsigned	ALIGN_BITS = 12
	Page size used by VirtIO. It's hard-coded to 4096 bytes in the spec for historical reasons. More...

static const unsigned	ALIGN_SIZE = 1 << ALIGN_BITS

Static Public Attributes inherited from Serializable
static int	ckptCount = 0

static int	ckptMaxCount = 0

static int	ckptPrevCount = -1

Protected Member Functions
	VirtQueue (PortProxy &proxy, uint16_t size)
	Instantiate a new virtqueue. More...

Private Member Functions
	VirtQueue ()

Private Attributes
const uint16_t	_size
	Queue size in terms of number of descriptors. More...

Addr	_address
	Base address of the queue. More...

PortProxy &	memProxy
	Guest physical memory proxy. More...

VirtRing< VirtDescriptor::Index >	avail
	Ring of available (incoming) descriptors. More...

VirtRing< struct vring_used_elem >	used
	Ring of used (outgoing) descriptors. More...

uint16_t	_last_avail
	Offset of last consumed descriptor in the VirtQueue::avail ring. More...

std::vector< VirtDescriptor >	descriptors
	Vector of pre-created descriptors indexed by their index into the queue. More...

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

static void	serializeAll (const std::string &cpt_dir)

static void	unserializeGlobals (CheckpointIn &cp)

Detailed Description

Base wrapper around a virtqueue.

VirtIO device models typically need to extend this class to implement their own device queues.

Note: Queues must be registered with VirtIODeviceBase::registerQueue() to be active.

Definition at line 317 of file base.hh.

Constructor & Destructor Documentation

virtual VirtQueue::~VirtQueue ( )

inlinevirtual

Definition at line 319 of file base.hh.

VirtQueue::VirtQueue	(	PortProxy &	proxy,
		uint16_t	size
	)

protected

Instantiate a new virtqueue.

Instantiate a virtqueue with a fixed size. The size is specified in descriptors which are defined as 4096 bytes each.

Parameters

proxy	Proxy to the guest physical memory.
size	Size in descriptors/pages.

Definition at line 227 of file base.cc.

References _size, descriptors, and ArmISA::i.

VirtQueue::VirtQueue ( )

private

Member Function Documentation

VirtDescriptor * VirtQueue::consumeDescriptor ( )

Get an incoming descriptor chain from the queue.

Returns: Pointer to descriptor on success, NULL if no pending descriptors are available.

Definition at line 271 of file base.cc.

References _last_avail, avail, ArmISA::d, descriptors, DPRINTF, VirtQueue::VirtRing< T >::header, MipsISA::index, VirtQueue::VirtRing< T >::read(), VirtQueue::VirtRing< T >::ring, VirtDescriptor::updateChain(), and used.

Referenced by onNotify(), and VirtIOConsole::TermRecvQueue::trySend().

void VirtQueue::dump ( ) const

Dump the contents of a queue.

Definition at line 304 of file base.cc.

References ArmISA::d, descriptors, and DTRACE.

Addr VirtQueue::getAddress ( ) const

inline

Get the guest physical address of this queue.

Returns: Physical address in guest where this queue resides.

Definition at line 341 of file base.hh.

References _address.

Referenced by VirtDescriptor::update().

VirtDescriptor* VirtQueue::getDescriptor ( VirtDescriptor::Index index )

inline

Get a pointer to a specific descriptor in the queue.

Note: This interfaces is normally only used by VirtDescriptor to follow descriptor chains. Device models typically don't need to use it.

Returns: Pointer to a VirtDescriptor.

Definition at line 359 of file base.hh.

References descriptors, and MipsISA::index.

Referenced by VirtDescriptor::next().

uint16_t VirtQueue::getSize ( ) const

inline

Get the number of descriptors available in this queue.

Returns: Size of queue in descriptors.

Definition at line 348 of file base.hh.

References _size.

Referenced by VirtIODeviceBase::getQueueSize().

void VirtQueue::onNotify ( )

virtual

Notify queue of pending events.

This method is called by VirtIODeviceBase::onNotify() to notify the device model of pending data in a virtqueue. The default implementation of this method iterates over the available descriptor chains and calls onNotifyDescriptor() for every new incoming chain.

Device models should normally overload one of onNotify() and onNotifyDescriptor().

Reimplemented in VirtIOConsole::TermRecvQueue.

Definition at line 314 of file base.cc.

References consumeDescriptor(), ArmISA::d, DPRINTF, and onNotifyDescriptor().

virtual void VirtQueue::onNotifyDescriptor ( VirtDescriptor * desc )

inlinevirtual

Notify queue of pending incoming descriptor.

This method is called by the default implementation of onNotify() to notify the device model of pending data in a descriptor chain.

Device models should normally overload one of onNotify() and onNotifyDescriptor().

Reimplemented in VirtIOBlock::RequestQueue, VirtIO9PBase::FSQueue, and VirtIOConsole::TermTransQueue.

Definition at line 421 of file base.hh.

Referenced by onNotify().

void VirtQueue::produceDescriptor	(	VirtDescriptor *	desc,
		uint32_t	len
	)

Send a descriptor chain to the guest.

This method posts a descriptor chain to the guest after a device model has finished processing it. The device model typically needs to call VirtIODeviceBase::kick() to deliver notify tell the guest that the queue has been updated.

Note: The desc parameter must refer to the first descriptor in a chain that has been retrieved using consumeDescriptor().; The len parameter specified the amount of data produced by the device model. It seems to be ignored by Linux and it is not well defined.

Parameters