virtq

package

v0.0.0-...-9c233c6 Latest Latest Go to latest Published: Feb 19, 2024 License: MIT Imports: 2 Imported by: 0

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Valid go.mod file
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Repository

github.com/c35s/hype

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Documentation ¶

Overview ¶

Package virtq partially implements packed virtqueues as described by the Virtual I/O Device (VIRTIO) Version 1.2 spec. Split virtqueues are not supported.

Index ¶

Constants
type Chain
- func (c *Chain) Buf(i int) ([]byte, error)
- func (c *Chain) Release(bytesWritten int) error
type Config
type Desc
type EventSuppress
- func (e EventSuppress) ShouldNotify(index uint16, wrap bool) bool
type Queue
- func New(ring []Desc, drvE, devE *EventSuppress, cfg Config) *Queue
- func (q *Queue) Next() (avail *Chain, err error)

Constants ¶

View Source

const (
	DescFNext     = 1 // buffer continues in the next descriptor
	DescFWrite    = 2 // buffer is device wo (otherwise ro)
	DescFIndirect = 4 // buffer contains a descriptor table
	DescFAvail    = 1 << 7
	DescFUsed     = 1 << 15
)

Variables ¶

This section is empty.

Functions ¶

This section is empty.

Types ¶

type Chain ¶

type Chain struct {
	Desc []Desc
	// contains filtered or unexported fields
}

Chain is a descriptor chain in a packed virtqueue.

func (*Chain) Buf ¶

func (c *Chain) Buf(i int) ([]byte, error)

Buf returns a slice aliasing the buffer described by the descriptor at the given index. It panics if the index is out of range. If the queue's MemAt callback fails, Buf returns the error.

func (*Chain) Release ¶

func (c *Chain) Release(bytesWritten int) error

Release marks the chain as used, recording the number of bytes written to the chain. It returns an error if the queue's Notify callback fails.

type Config ¶

type Config struct {
	MemAt  func(addr uint64, len int) ([]byte, error)
	Notify func() error
}

func (Desc) Continues ¶

func (d Desc) Continues() bool

Continues returns true if the descriptor's buffer continues in the next descriptor.

func (Desc) IsIndirect ¶

func (d Desc) IsIndirect() bool

IsIndirect returns true if the descriptor's buffer contains more descriptors.

func (Desc) IsRO ¶

func (d Desc) IsRO() bool

IsRO returns true if the descriptor's buffer is device read-only.

func (Desc) IsWO ¶

func (d Desc) IsWO() bool

IsWO returns true if the descriptor's buffer is device write-only.

type EventSuppress ¶

type EventSuppress struct {
	Desc  uint16
	Flags uint16
}

EventSuppress is the driver or device event suppression area for a packed virtqueue.

func (EventSuppress) ShouldNotify ¶

func (e EventSuppress) ShouldNotify(index uint16, wrap bool) bool

ShouldNotify returns true if a notification should be sent for the given descriptor index and wrap counter, or false if the event is suppressed.

func New ¶

func New(ring []Desc, drvE, devE *EventSuppress, cfg Config) *Queue

New returns a new virtqueue backed by the given ring and event suppression areas.

func (*Queue) Next ¶

func (q *Queue) Next() (avail *Chain, err error)

Next returns the next available descriptor chain, or nil if no descriptors are available. It returns an error if the queue's MemAt callback fails while resolving an indirect descriptor, or if an indirect descriptor has a malformed buffer.

Source Files ¶

View all Source files

virtq.go

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