Simple class for accessing a virtio block device synchronously. More...

#include <virtio-block>

Inheritance diagram for L4virtio::Driver::Block_device:

Collaboration diagram for L4virtio::Driver::Block_device:

Data Structures
class	Handle
	Handle to an ongoing request. More...

Public Member Functions
void	setup_device (L4::Cap< L4virtio::Device > srvcap, l4_size_t usermem, void **userdata, Ptr< void > &user_devaddr, L4::Cap< L4Re::Dataspace > qds=L4::Cap< L4Re::Dataspace >(), l4_uint32_t fmask0=-1U, l4_uint32_t fmask1=-1U)
	Establish a connection to the device and set up shared memory.

l4virtio_block_config_t const &	device_config () const
	Return a reference to the device configuration.

Handle	start_request (l4_uint64_t sector, l4_uint32_t type, Callback callback)
	Start the setup of a new request.

int	add_block (Handle handle, Ptr< void > addr, l4_uint32_t size)
	Add a data block to a request that has already been set up.

int	send_request (Handle handle)
	Process request asynchronously.

int	process_request (Handle handle)
	Process request synchronously.

void	process_used_queue ()
	Process and free all items in the used queue.

Public Member Functions inherited from L4virtio::Driver::Device
void	driver_connect (L4::Cap< L4virtio::Device > srvcap, bool manage_notify=true)
	Contacts the device and starts the initial handshake.

int	bind_notification_irq (unsigned index, L4::Cap< L4::Triggerable > irq) const
	Register a triggerable to receive notifications from the device.

bool	fail_state () const
	Return true if the device is in a fail state.

bool	feature_negotiated (unsigned int feat) const
	Check if a particular feature bit was negotiated with the device.

int	driver_acknowledge ()
	Finalize handshake with the device.

int	register_ds (L4::Cap< L4Re::Dataspace > ds, l4_umword_t offset, l4_umword_t size, l4_uint64_t *devaddr)
	Share a dataspace with the device.

int	config_queue (int num, unsigned size, l4_uint64_t desc_addr, l4_uint64_t avail_addr, l4_uint64_t used_addr)
	Send the virtqueue configuration to the device.

int	max_queue_size (int num) const
	Maximum queue size allowed by the device.

int	send_and_wait (Virtqueue &queue, l4_uint16_t descno)
	Send a request to the device and wait for it to be processed.

int	wait (int index) const
	Wait for a notification from the device.

int	wait_for_next_used (Virtqueue &queue, l4_uint32_t *len=nullptr) const
	Wait for the next item to arrive in the used queue and return it.

void	send (Virtqueue &queue, l4_uint16_t descno)
	Send a request to the device.

Detailed Description

Simple class for accessing a virtio block device synchronously.

Definition at line 36 of file virtio-block.

Member Function Documentation

◆ add_block()

int L4virtio::Driver::Block_device::add_block	(	Handle	handle,
		Ptr< void >	addr,
		l4_uint32_t	size
	)

inline

Add a data block to a request that has already been set up.

Parameters

handle	Handle to request previously set up with start_request().
addr	Address of data block in device address space.
size	Size of data block.

Return values

L4_OK	Block was successfully added.
-L4_EAGAIN	No descriptors available. Try again later.

Definition at line 229 of file virtio-block.

References L4virtio::Virtqueue::Desc::addr, L4virtio::Driver::Virtqueue::alloc_descriptor(), L4virtio::Driver::Virtqueue::desc(), L4virtio::Virtqueue::Desc::flags, L4_EAGAIN, L4_EOK, L4virtio::Virtqueue::Desc::len, L4virtio::Virtqueue::Desc::Flags::next(), L4virtio::Virtqueue::Desc::next, L4virtio::Virtqueue::Desc::Flags::raw, l4virtio_block_header_t::type, and L4virtio::Virtqueue::Desc::Flags::write().

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◆ process_request()

int L4virtio::Driver::Block_device::process_request ( Handle handle )

inline

Process request synchronously.

Parameters

handle Handle to request to process.

Return values

L4_EOK	Request processed successfully.
-L4_EAGAIN	No descriptors available. Try again later.
-L4_EIO	IO error during request processing.
-L4_ENOSYS	Unsupported request.
<0	Another unspecified error occurred.

Sends a request to the driver that was previously set up with start_request() and add_block() and wait for it to be executed.

Definition at line 306 of file virtio-block.

References L4virtio::Virtqueue::Desc::addr, L4virtio::Driver::Virtqueue::alloc_descriptor(), L4virtio::Driver::Virtqueue::desc(), L4virtio::Virtqueue::Desc::flags, L4_EAGAIN, L4_EINVAL, L4_EIO, L4_ENOSYS, L4_EOK, L4VIRTIO_BLOCK_S_IOERR, L4VIRTIO_BLOCK_S_OK, L4VIRTIO_BLOCK_S_UNSUPP, L4virtio::Virtqueue::Desc::len, L4virtio::Virtqueue::Desc::Flags::next(), L4virtio::Virtqueue::Desc::next, L4virtio::Virtqueue::Desc::Flags::raw, L4virtio::Driver::Device::send_and_wait(), and L4virtio::Virtqueue::Desc::Flags::write().

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◆ process_used_queue()

void L4virtio::Driver::Block_device::process_used_queue ( )

inline

Process and free all items in the used queue.

If the request has a callback registered it is called after the item has been removed from the queue.

Definition at line 357 of file virtio-block.

References L4Re::chksys(), L4virtio::Driver::Virtqueue::find_next_used(), L4_ENOSYS, and L4virtio::Virtqueue::num().

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◆ send_request()

int L4virtio::Driver::Block_device::send_request ( Handle handle )

inline

Process request asynchronously.

Parameters

handle Handle to request to send to the device

Return values

L4_OK	Request was successfully scheduled.
-L4_EAGAIN	No descriptors available. Try again later.

Sends a request to the driver that was previously set up with start_request() and add_block() and wait for it to be executed.

Definition at line 265 of file virtio-block.

References L4virtio::Virtqueue::Desc::addr, L4virtio::Driver::Virtqueue::alloc_descriptor(), L4virtio::Driver::Virtqueue::desc(), L4virtio::Virtqueue::Desc::flags, L4_EAGAIN, L4_EOK, L4virtio::Virtqueue::Desc::len, L4virtio::Virtqueue::Desc::Flags::next(), L4virtio::Virtqueue::Desc::next, L4virtio::Virtqueue::Desc::Flags::raw, L4virtio::Driver::Device::send(), and L4virtio::Virtqueue::Desc::Flags::write().

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◆ setup_device()

void L4virtio::Driver::Block_device::setup_device	(	L4::Cap< L4virtio::Device >	srvcap,
		l4_size_t	usermem,
		void **	userdata,
		Ptr< void > &	user_devaddr,
		L4::Cap< L4Re::Dataspace >	qds = `L4::Cap<L4Re::Dataspace>()`,
		l4_uint32_t	fmask0 = `-1U`,
		l4_uint32_t	fmask1 = `-1U`
	)

inline

Establish a connection to the device and set up shared memory.

Parameters

	srvcap	IPC capability of the channel to the server.
	usermem	Size of additional memory to share with device.
[out]	userdata	Pointer to the region of user-usable memory.
[out]	user_devaddr	Address of user-usable memory in device address space.
	qds	External queue dataspace. If this capability is invalid, the function will attempt to allocate a dataspace on its own. Note that the external queue dataspace must be large enough.
	fmask0	Feature bits 0..31 that the driver supports.
	fmask1	Feature bits 32..63 that the driver supports.

This function starts a handshake with the device and sets up the virtqueues for communication and the additional data structures for the block device. It will also allocate and share additional memory that the caller then can use freely, i.e. normally this memory would be used as a reception buffer. The caller may also decide to not make use of this convenience function and request 0 bytes in usermem. Then it has to allocate the block buffers for sending/receiving payload manually and share them using register_ds().

Definition at line 92 of file virtio-block.

References L4virtio::Virtqueue::avail_offset(), L4Re::chkcap(), L4Re::chksys(), L4virtio::Driver::Device::config_queue(), L4Re::Mem_alloc::Continuous, L4virtio::Driver::Device::driver_acknowledge(), L4virtio::Driver::Device::driver_connect(), L4Re::Env::env(), L4Re::Rm::Unique_region< T >::get(), L4virtio::Driver::Virtqueue::init_queue(), L4_EINVAL, L4_ENODEV, L4_PAGESHIFT, l4_round_page(), l4_round_size(), L4VIRTIO_ID_BLOCK, L4::Ipc::make_cap_rw(), L4virtio::Driver::Device::max_queue_size(), L4Re::Mem_alloc::Pinned, L4virtio::Driver::Device::register_ds(), L4Re::Rm::F::RW, L4Re::Rm::F::Search_addr, L4virtio::Virtqueue::total_size(), and L4virtio::Virtqueue::used_offset().

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◆ start_request()

Handle L4virtio::Driver::Block_device::start_request	(	l4_uint64_t	sector,
		l4_uint32_t	type,
		Callback	callback
	)

inline

Start the setup of a new request.

Parameters

sector	First sector to write to/read from.
type	Request type.
callback	Function to call, when the request is finished. May be 0 for synchronous requests.

Definition at line 191 of file virtio-block.

References L4virtio::Virtqueue::Desc::addr, L4virtio::Driver::Virtqueue::alloc_descriptor(), L4virtio::Driver::Virtqueue::desc(), L4virtio::Virtqueue::Desc::flags, l4virtio_block_header_t::ioprio, L4virtio::Virtqueue::Desc::len, L4virtio::Virtqueue::Desc::Flags::raw, l4virtio_block_header_t::sector, and l4virtio_block_header_t::type.

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

l4/l4virtio/client/virtio-block

Data Structures

Public Member Functions

Detailed Description

Member Function Documentation

◆ add_block()

◆ process_request()

◆ process_used_queue()

◆ send_request()

◆ setup_device()

◆ start_request()