Base class for virtio block devices. More...

#include <virtio-block>

Inheritance diagram for L4virtio::Svr::Block_dev_base< Ds_data >:

Collaboration diagram for L4virtio::Svr::Block_dev_base< Ds_data >:

Public Member Functions
	Block_dev_base (l4_uint32_t vendor, unsigned queue_size, l4_uint64_t capacity, bool read_only)
	Create a new virtio block device.

virtual bool	process_request (cxx::unique_ptr< Request > &&req)=0
	Implements the actual processing of data in the device.

virtual void	reset_device ()=0
	Reset the actual hardware device.

virtual bool	queue_stopped ()=0
	Return true, if the queues should not be processed further.

void	finalize_request (cxx::unique_ptr< Request > req, unsigned sz, l4_uint8_t status=L4VIRTIO_BLOCK_S_OK)
	Releases resources related to a request and notifies the client.

int	reconfig_queue (unsigned idx) override
	callback for client queue-config request

void	reset () override
	reset callback, called for doing a device reset

Public Member Functions inherited from L4virtio::Svr::Device_t< Ds_data >
virtual bool	check_features ()
	callback for checking the subset of accepted features

virtual L4::Cap< L4::Irq >	device_notify_irq (unsigned idx)
	Callback to gather the device notification IRQ (multi IRQ).

virtual void	register_driver_irq (unsigned idx)
	Callback for registering an notification IRQ (multi IRQ).

virtual unsigned	num_events_supported () const
	Return the highest notification index supported.

	Device_t (Dev_config *dev_config)
	Make a device for the given config.

Mem_list const *	mem_info () const
	Get the memory region list used for this device.

void	reset_queue_config (unsigned idx, unsigned num_max, bool inc_generation=false)
	Trigger reset for the configuration space for queue idx.

void	init_mem_info (unsigned num)
	Initialize the memory region list to the given maximum.

void	device_error ()
	Transition device into DEVICE_NEEDS_RESET state.

bool	setup_queue (Virtqueue *q, unsigned qn, unsigned num_max)
	Enable/disable the specified queue.

bool	handle_mem_cmd_write ()
	Check for a value in the `cmd` register and handle a write.

void	enable_trusted_ds_validation ()
	Enable trusted dataspace validation.

void	add_trusted_dataspaces (std::shared_ptr< Ds_vector const > ds)
	Provide a list of trusted dataspaces that can be used for validation.

Protected Member Functions
void	set_size_max (l4_uint32_t sz)
	Sets the maximum size of any single segment reported to client.

void	set_seg_max (l4_uint32_t sz)
	Sets the maximum number of segments in a request that is reported to client.

void	set_geometry (l4_uint16_t cylinders, l4_uint8_t heads, l4_uint8_t sectors)
	Set disk geometry that is reported to the client.

void	set_blk_size (l4_uint32_t sz)
	Sets block disk size to be reported to the client.

void	set_topology (l4_uint8_t physical_block_exp, l4_uint8_t alignment_offset, l4_uint32_t min_io_size, l4_uint32_t opt_io_size)
	Sets the I/O alignment information reported back to the client.

void	set_flush ()
	Enables the flush command.

void	set_config_wce (l4_uint8_t writeback)
	Sets cache mode and enables the writeback toggle.

l4_uint8_t	get_writeback ()
	Get the writeback field from the configuration space.

void	set_discard (l4_uint32_t max_discard_sectors, l4_uint32_t max_discard_seg, l4_uint32_t discard_sector_alignment)
	Sets constraints for and enables the discard command.

void	set_write_zeroes (l4_uint32_t max_write_zeroes_sectors, l4_uint32_t max_write_zeroes_seg, l4_uint8_t write_zeroes_may_unmap)
	Sets constraints for and enables the write zeroes command.

Additional Inherited Members
Protected Attributes inherited from L4virtio::Svr::Device_t< Ds_data >
Mem_list	_mem_info
	Memory region list.

Detailed Description

template<typename Ds_data>
class L4virtio::Svr::Block_dev_base< Ds_data >

Base class for virtio block devices.

Use this class as a base to implement your own specific block device.

Definition at line 257 of file virtio-block.

Constructor & Destructor Documentation

◆ Block_dev_base()

template<typename Ds_data >

L4virtio::Svr::Block_dev_base< Ds_data >::Block_dev_base	(	l4_uint32_t	vendor,
		unsigned	queue_size,
		l4_uint64_t	capacity,
		bool	read_only
	)

inline

Create a new virtio block device.

Parameters

vendor	Vendor ID
queue_size	Number of entries to provide in avail and used queue.
capacity	Size of the device in 512-byte sectors.
read_only	True, if the device should not be writable.

Definition at line 462 of file virtio-block.

References L4virtio::Svr::Device_t< Ds_data >::reset_queue_config().

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Member Function Documentation

◆ finalize_request()

template<typename Ds_data >

void L4virtio::Svr::Block_dev_base< Ds_data >::finalize_request	(	cxx::unique_ptr< Request >	req,
		unsigned	sz,
		l4_uint8_t	status = `L4VIRTIO_BLOCK_S_OK`
	)

inline

Releases resources related to a request and notifies the client.

Parameters

req	Pointer to request that has finished.
sz	Number of bytes consumed.
status	Status of request (see L4virtio_block_status).

This function must be called when an asynchronous request finishes, either successfully or with an error. The status byte in the request must have been set prior to calling it.

Definition at line 515 of file virtio-block.

References L4virtio::Svr::Device_t< Ds_data >::device_error(), and L4virtio::Virtqueue::ready().

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◆ get_writeback()

template<typename Ds_data >

l4_uint8_t L4virtio::Svr::Block_dev_base< Ds_data >::get_writeback ( )

inlineprotected

Get the writeback field from the configuration space.

Returns: Value of the writeback field.

Definition at line 406 of file virtio-block.

◆ process_request()

template<typename Ds_data >

virtual bool L4virtio::Svr::Block_dev_base< Ds_data >::process_request ( cxx::unique_ptr< Request > && req )

pure virtual

Implements the actual processing of data in the device.

Parameters

req	The request to be processed.

Returns: If false, no further requests will be scheduled.

Synchronous and asynchronous processing of the data is supported. For asynchronous mode, the function should set up the worker and then return false. In synchronous mode, the function should return true, once processing is complete. If there is an error and processing is aborted, the status flag of req needs to be set accordingly and the request immediately finished with finish_request() if the client is to be answered.

◆ set_blk_size()

template<typename Ds_data >

void L4virtio::Svr::Block_dev_base< Ds_data >::set_blk_size ( l4_uint32_t sz )

inlineprotected

Sets block disk size to be reported to the client.

Setting this does not change the logical sector size used for addressing the device.

Definition at line 350 of file virtio-block.

◆ set_config_wce()

template<typename Ds_data >

void L4virtio::Svr::Block_dev_base< Ds_data >::set_config_wce ( l4_uint8_t writeback )

inlineprotected

Sets cache mode and enables the writeback toggle.

Parameters

writeback Mode of the cache (0 for writethrough, 1 for writeback).

Definition at line 393 of file virtio-block.

◆ set_discard()

template<typename Ds_data >

void L4virtio::Svr::Block_dev_base< Ds_data >::set_discard	(	l4_uint32_t	max_discard_sectors,
		l4_uint32_t	max_discard_seg,
		l4_uint32_t	discard_sector_alignment
	)

inlineprotected

Sets constraints for and enables the discard command.

Parameters

max_discard_sectors	Maximum discard sectors size.
max_discard_seg	Maximum discard segment number.
discard_sector_alignment	Can be used by the driver when splitting a request based on alignment.

Definition at line 420 of file virtio-block.

◆ set_size_max()

template<typename Ds_data >

void L4virtio::Svr::Block_dev_base< Ds_data >::set_size_max ( l4_uint32_t sz )

inlineprotected

Sets the maximum size of any single segment reported to client.

The limit is also applied to any incoming requests. Requests with larger segments result in an IO error being reported to the client. That means that process_request() can safely make the assumption that all segments in the received request are smaller.

Definition at line 308 of file virtio-block.

◆ set_topology()

template<typename Ds_data >

void L4virtio::Svr::Block_dev_base< Ds_data >::set_topology	(	l4_uint8_t	physical_block_exp,
		l4_uint8_t	alignment_offset,
		l4_uint32_t	min_io_size,
		l4_uint32_t	opt_io_size
	)

inlineprotected

Sets the I/O alignment information reported back to the client.

Parameters

physical_block_exp	Number of logical blocks per physical block(log2)
alignment_offset	Offset of the first aligned logical block
min_io_size	Suggested minimum I/O size in blocks
opt_io_size	Optimal I/O size in blocks

Definition at line 366 of file virtio-block.

◆ set_write_zeroes()

template<typename Ds_data >

void L4virtio::Svr::Block_dev_base< Ds_data >::set_write_zeroes	(	l4_uint32_t	max_write_zeroes_sectors,
		l4_uint32_t	max_write_zeroes_seg,
		l4_uint8_t	write_zeroes_may_unmap
	)

inlineprotected

Sets constraints for and enables the write zeroes command.

Parameters

max_write_zeroes_sectors	Maximum write zeroes sectors size.
max_write_zeroes_seg	maximum write zeroes segment number.
write_zeroes_may_unmap	Set if a write zeroes request can result in deallocating one or more sectors.

Definition at line 440 of file virtio-block.

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

l4/l4virtio/server/virtio-block

Public Member Functions

Protected Member Functions

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ Block_dev_base()

Member Function Documentation

◆ finalize_request()

◆ get_writeback()

◆ process_request()

◆ set_blk_size()

◆ set_config_wce()

◆ set_discard()

◆ set_size_max()

◆ set_topology()

◆ set_write_zeroes()