Abstraction for L4-Virtio device config memory. More...

#include <l4virtio>

Inherited by L4virtio::Svr::Dev_config_t< l4virtio_block_config_t >, and L4virtio::Svr::Dev_config_t< PRIV_CONFIG >.

Collaboration diagram for L4virtio::Svr::Dev_config:

Public Member Functions
	Dev_config (l4_uint32_t vendor, l4_uint32_t device, unsigned cfg_size, l4_uint32_t num_queues=0)
	Create a L4-Virtio config data space.

	Dev_config (Cfg_cap const &cfg, l4_addr_t cfg_offset, l4_uint32_t vendor, l4_uint32_t device, unsigned cfg_size, l4_uint32_t num_queues=0)
	Setup an L4-Virtio config space in an existing data space.

l4_uint32_t	guest_features (unsigned idx) const
	Return a specific set of guest features.

l4_uint32_t	negotiated_features (unsigned idx) const
	Compute a specific set of negotiated features.

Status	status () const
	Get current device status (trusted).

l4_uint32_t	get_cmd () const
	Get the value from the `cmd` register.

void	reset_cmd ()
	Reset the `cmd` register after execution of a command.

void	set_status (Status status)
	Set device status register.

void	set_device_needs_reset ()
	Set DEVICE_NEEDS_RESET bit in device status register.

bool	change_queue_config (l4_uint32_t num_queues)
	Setup new queue configuration.

l4virtio_config_queue_t volatile const *	qconfig (unsigned index) const
	Get queue read-only config data for queue with the given index.

void	reset_hdr (bool inc_generation=false) const
	Reset the config header to the initial contents.

bool	reset_queue (unsigned index, unsigned num_max, bool inc_generation=false) const
	Reset queue config for the given queue.

l4virtio_config_hdr_t const volatile *	hdr () const
	Get a read-only pointer to the config header.

L4::Cap< L4Re::Dataspace >	ds () const
	Get data-space capability for the shared config data space.

l4_addr_t	ds_offset () const
	Return the offset into the config dataspace where the device configuration starts.

Detailed Description

Abstraction for L4-Virtio device config memory.

Virtio defines a device configuration mechanism, L4-Virtio implements this mechanism based on shared memory a set_status() and a config_queue() call. This class provides an abstraction for L4-Virtio host implementations to establish such a shared memory data space and providing the necessary contents and access functions.

Definition at line 52 of file l4virtio.

Constructor & Destructor Documentation

◆ Dev_config() [1/2]

L4virtio::Svr::Dev_config::Dev_config	(	l4_uint32_t	vendor,
		l4_uint32_t	device,
		unsigned	cfg_size,
		l4_uint32_t	num_queues = `0`
	)

inline

Create a L4-Virtio config data space.

Parameters

vendor	The vendor ID to store in config header.
device	The device ID to store in config header.
cfg_size	The size of the device-specific config data in bytes.
num_queues	The number of queues provided by the device.

This constructor allocates a data space used for L4-virtio config attaches the data space to the local address space and writes the initial contents to the config header.

Definition at line 112 of file l4virtio.

References L4Re::chkcap(), L4Re::chksys(), L4Re::Env::env(), and L4_PAGESIZE.

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◆ Dev_config() [2/2]

L4virtio::Svr::Dev_config::Dev_config	(	Cfg_cap const &	cfg,
		l4_addr_t	cfg_offset,
		l4_uint32_t	vendor,
		l4_uint32_t	device,
		unsigned	cfg_size,
		l4_uint32_t	num_queues = `0`
	)

inline

Setup an L4-Virtio config space in an existing data space.

Parameters

cfg	Dataspace that should hold the L4-Virtio configuration.
cfg_offset	Offset into the dataspace where the configuration starts.
vendor	The vendor ID to store in config header.
device	The device ID to store in config header.
cfg_size	The size of the device-specific config data in bytes.
num_queues	The number of queues provided by the device.

Definition at line 146 of file l4virtio.

References L4_PAGESIZE.

Member Function Documentation

◆ change_queue_config()

bool L4virtio::Svr::Dev_config::change_queue_config ( l4_uint32_t num_queues )

inline

Setup new queue configuration.

Parameters

num_queues The number of queues provided by the device.

Definition at line 269 of file l4virtio.

References L4_PAGESIZE, and reset_hdr().

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◆ ds()

L4::Cap< L4Re::Dataspace > L4virtio::Svr::Dev_config::ds ( ) const

inline

Get data-space capability for the shared config data space.

Returns: Capability for the shared config data space.

Definition at line 358 of file l4virtio.

◆ get_cmd()

l4_uint32_t L4virtio::Svr::Dev_config::get_cmd ( ) const

inline

Get the value from the cmd register.

Note, the most significant eight bits are the command (0 is nothing to do). The upper eight bit are reset to zero after the command was handled.

Definition at line 224 of file l4virtio.

References l4virtio_config_hdr_t::cmd, and hdr().

Referenced by L4virtio::Svr::Device_t< DATA >::handle_mem_cmd_write().

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◆ guest_features()

l4_uint32_t L4virtio::Svr::Dev_config::guest_features ( unsigned idx ) const

inline

Return a specific set of guest features.

Parameters

idx	Index into the guest features array.

Return values

The	selected set of guest features.

This function returns a specific 32bit set of features enabled by the guest/driver. idx is the index in the guest features array, resp. the 32 bit set to return.

Definition at line 192 of file l4virtio.

◆ hdr()

l4virtio_config_hdr_t const volatile * L4virtio::Svr::Dev_config::hdr ( ) const

inline

Get a read-only pointer to the config header.

Returns: Read-only pointer to the shared config header.

Definition at line 351 of file l4virtio.

References L4Re::Rm::Unique_region< T >::get().

Referenced by get_cmd(), reset_cmd(), set_device_needs_reset(), and set_status().

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◆ negotiated_features()

l4_uint32_t L4virtio::Svr::Dev_config::negotiated_features ( unsigned idx ) const

inline

Compute a specific set of negotiated features.

Parameters

idx	Index into the guest/host features array.

Return values

The	selected set of negotiated features.

This function returns a specific 32-bit set of features negotiated by the guest/driver and host/device. idx is the index in the guest/host features array, resp. the 32-bit set to return.

Definition at line 206 of file l4virtio.

◆ qconfig()

l4virtio_config_queue_t volatile const * L4virtio::Svr::Dev_config::qconfig ( unsigned index ) const

inline

Get queue read-only config data for queue with the given index.

Parameters

index The index of the queue.

Returns: Read-only pointer to the config of the queue with the given index, or NULL if index is out of range.

Definition at line 286 of file l4virtio.

References L4Re::Rm::Unique_region< T >::get(), and L4_UNLIKELY.

Referenced by reset_queue(), and L4virtio::Svr::Device_t< DATA >::setup_queue().

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◆ reset_cmd()

void L4virtio::Svr::Dev_config::reset_cmd ( )

inline

Reset the cmd register after execution of a command.

This function resets the cmd register in order for the client to detect that the command was executed by the device.

Definition at line 235 of file l4virtio.

References l4virtio_config_hdr_t::cmd, and hdr().

Referenced by L4virtio::Svr::Device_t< DATA >::handle_mem_cmd_write().

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◆ reset_queue()

bool L4virtio::Svr::Dev_config::reset_queue	(	unsigned	index,
		unsigned	num_max,
		bool	inc_generation = `false`
	)		const

inline

Reset queue config for the given queue.

Parameters

index	The index of the queue to reset.
num_max	The maximum number of descriptors supported by this queue.
inc_generation	The config generation will be incremented when this is true.

Returns: true on success, or false when index is out of range.

Definition at line 328 of file l4virtio.

References L4_UNLIKELY, l4virtio_config_queue_t::num, l4virtio_config_queue_t::num_max, qconfig(), and l4virtio_config_queue_t::ready.

Referenced by L4virtio::Svr::Device_t< DATA >::reset_queue_config().

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◆ set_device_needs_reset()

void L4virtio::Svr::Dev_config::set_device_needs_reset ( )

inline

Set DEVICE_NEEDS_RESET bit in device status register.

This function sets the internal status register and also the status register in the shared memory to DEVICE_NEEDS_RESET.

Definition at line 259 of file l4virtio.

References L4virtio::Svr::Dev_status::device_needs_reset(), hdr(), L4virtio::Svr::Dev_status::raw, and l4virtio_config_hdr_t::status.

Referenced by L4virtio::Svr::Device_t< DATA >::device_error().

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◆ set_status()

void L4virtio::Svr::Dev_config::set_status ( Status status )

inline

Set device status register.

Parameters

status The new value for the device status register.

This function sets the internal status register and also the status register in the shared memory to status.

Definition at line 247 of file l4virtio.

References hdr(), L4virtio::Svr::Dev_status::raw, status(), and l4virtio_config_hdr_t::status.

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◆ status()

Status L4virtio::Svr::Dev_config::status ( ) const

inline

Get current device status (trusted).

Returns: Current device status register (trusted).

The status returned by this function is value stored internally and cannot be written by the guest (i.e., the value can be taken as trusted.)

Definition at line 216 of file l4virtio.

Referenced by L4virtio::Svr::Device_t< DATA >::device_error(), and set_status().

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

l4/l4virtio/server/l4virtio

Public Member Functions

Detailed Description

Constructor & Destructor Documentation

◆ Dev_config() [1/2]

◆ Dev_config() [2/2]

Member Function Documentation

◆ change_queue_config()

◆ ds()

◆ get_cmd()

◆ guest_features()

◆ hdr()

◆ negotiated_features()

◆ qconfig()

◆ reset_cmd()

◆ reset_queue()

◆ set_device_needs_reset()

◆ set_status()

◆ status()