Struct Cap

#[repr(C)]
pub struct Cap {
    pub cap_vndr: u8,
    pub cap_next: u8,
    pub cap_len: u8,
    pub cfg_type: u8,
    pub bar: u8,
    pub id: u8,
    pub padding: [u8; 2],
    pub offset: le32,
    pub length: le32,
}

PCI Capability

See CapData for reading additional fields.

Fields

cap_vndr: u8

Generic PCI field: PCI_CAP_ID_VNDR

0x09; Identifies a vendor-specific capability.

cap_next: u8

Generic PCI field: next ptr.

Link to next capability in the capability list in the PCI configuration space.

cap_len: u8

Generic PCI field: capability length

Length of this capability structure, including the whole of struct virtio_pci_cap, and extra data if any. This length MAY include padding, or fields unused by the driver.

cfg_type: u8

Identifies the structure.

Each structure is detailed individually below.

The device MAY offer more than one structure of any type - this makes it possible for the device to expose multiple interfaces to drivers. The order of the capabilities in the capability list specifies the order of preference suggested by the device. A device may specify that this ordering mechanism be overridden by the use of the id field.

For example, on some hypervisors, notifications using IO accesses are faster than memory accesses. In this case, the device would expose two capabilities with cfg_type set to VIRTIO_PCI_CAP_NOTIFY_CFG: the first one addressing an I/O BAR, the second one addressing a memory BAR. In this example, the driver would use the I/O BAR if I/O resources are available, and fall back on memory BAR when I/O resources are unavailable.

bar: u8

Where to find it.

values 0x0 to 0x5 specify a Base Address register (BAR) belonging to the function located beginning at 10h in PCI Configuration Space and used to map the structure into Memory or I/O Space. The BAR is permitted to be either 32-bit or 64-bit, it can map Memory Space or I/O Space.

Any other value is reserved for future use.

id: u8

Multiple capabilities of the same type

Used by some device types to uniquely identify multiple capabilities of a certain type. If the device type does not specify the meaning of this field, its contents are undefined.

padding: [u8; 2]

Pad to full dword.

offset: le32

Offset within bar.

indicates where the structure begins relative to the base address associated with the BAR. The alignment requirements of offset are indicated in each structure-specific section below.

length: le32

Length of the structure, in bytes.

indicates the length of the structure.

length MAY include padding, or fields unused by the driver, or future extensions.

For example, a future device might present a large structure size of several MBytes. As current devices never utilize structures larger than 4KBytes in size, driver MAY limit the mapped structure size to e.g. 4KBytes (thus ignoring parts of structure after the first 4KBytes) to allow forward compatibility with such devices without loss of functionality and without wasting resources.

Implementations

impl Cap

pub fn read( addr: PciCapabilityAddress, access: impl ConfigRegionAccess, ) -> Option<Self>

Trait Implementations

impl Clone for Cap

fn clone(&self) -> Cap

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Cap

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl FromBytes for Cap

where u8: FromBytes, [u8; 2]: FromBytes, le32: FromBytes,

fn ref_from_bytes( source: &[u8], ) -> Result<&Self, ConvertError<AlignmentError<&[u8], Self>, SizeError<&[u8], Self>, Infallible>>

where Self: KnownLayout + Immutable,

Interprets the given source as a &Self.

fn ref_from_prefix( source: &[u8], ) -> Result<(&Self, &[u8]), ConvertError<AlignmentError<&[u8], Self>, SizeError<&[u8], Self>, Infallible>>

where Self: KnownLayout + Immutable,

Interprets the prefix of the given source as a &Self without copying.

fn ref_from_suffix( source: &[u8], ) -> Result<(&[u8], &Self), ConvertError<AlignmentError<&[u8], Self>, SizeError<&[u8], Self>, Infallible>>

where Self: Immutable + KnownLayout,

Interprets the suffix of the given bytes as a &Self.

fn ref_from_bytes_with_elems( source: &[u8], count: usize, ) -> Result<&Self, ConvertError<AlignmentError<&[u8], Self>, SizeError<&[u8], Self>, Infallible>>

where Self: KnownLayout<PointerMetadata = usize> + Immutable,

Interprets the given source as a &Self with a DST length equal to count.

fn ref_from_prefix_with_elems( source: &[u8], count: usize, ) -> Result<(&Self, &[u8]), ConvertError<AlignmentError<&[u8], Self>, SizeError<&[u8], Self>, Infallible>>

where Self: KnownLayout<PointerMetadata = usize> + Immutable,

Interprets the prefix of the given source as a DST &Self with length equal to count.

fn ref_from_suffix_with_elems( source: &[u8], count: usize, ) -> Result<(&[u8], &Self), ConvertError<AlignmentError<&[u8], Self>, SizeError<&[u8], Self>, Infallible>>

where Self: KnownLayout<PointerMetadata = usize> + Immutable,

Interprets the suffix of the given source as a DST &Self with length equal to count.

fn read_from_bytes(source: &[u8]) -> Result<Self, SizeError<&[u8], Self>>

where Self: Sized,

Reads a copy of Self from the given source.

fn read_from_prefix( source: &[u8], ) -> Result<(Self, &[u8]), SizeError<&[u8], Self>>

where Self: Sized,

Reads a copy of Self from the prefix of the given source.

fn read_from_suffix( source: &[u8], ) -> Result<(&[u8], Self), SizeError<&[u8], Self>>

where Self: Sized,

Reads a copy of Self from the suffix of the given source.

impl FromZeros for Cap

where u8: FromZeros, [u8; 2]: FromZeros, le32: FromZeros,

fn zero(&mut self)

Overwrites self with zeros.

fn new_zeroed() -> Self

where Self: Sized,

Creates an instance of Self from zeroed bytes.

impl KnownLayout for Cap

where le32: KnownLayout,

type PointerMetadata = <Le<u32> as KnownLayout>::PointerMetadata

The type of metadata stored in a pointer to Self.

impl TryFromBytes for Cap

where u8: TryFromBytes, [u8; 2]: TryFromBytes, le32: TryFromBytes,

fn try_ref_from_bytes( source: &[u8], ) -> Result<&Self, ConvertError<AlignmentError<&[u8], Self>, SizeError<&[u8], Self>, ValidityError<&[u8], Self>>>

where Self: KnownLayout + Immutable,

Attempts to interpret the given source as a &Self.

fn try_ref_from_prefix( source: &[u8], ) -> Result<(&Self, &[u8]), ConvertError<AlignmentError<&[u8], Self>, SizeError<&[u8], Self>, ValidityError<&[u8], Self>>>

where Self: KnownLayout + Immutable,

Attempts to interpret the prefix of the given source as a &Self.

fn try_ref_from_suffix( source: &[u8], ) -> Result<(&[u8], &Self), ConvertError<AlignmentError<&[u8], Self>, SizeError<&[u8], Self>, ValidityError<&[u8], Self>>>

where Self: KnownLayout + Immutable,

Attempts to interpret the suffix of the given source as a &Self.

fn try_ref_from_bytes_with_elems( source: &[u8], count: usize, ) -> Result<&Self, ConvertError<AlignmentError<&[u8], Self>, SizeError<&[u8], Self>, ValidityError<&[u8], Self>>>

where Self: KnownLayout<PointerMetadata = usize> + Immutable,

Attempts to interpret the given source as a &Self with a DST length equal to count.

fn try_ref_from_prefix_with_elems( source: &[u8], count: usize, ) -> Result<(&Self, &[u8]), ConvertError<AlignmentError<&[u8], Self>, SizeError<&[u8], Self>, ValidityError<&[u8], Self>>>

where Self: KnownLayout<PointerMetadata = usize> + Immutable,

Attempts to interpret the prefix of the given source as a &Self with a DST length equal to count.

fn try_ref_from_suffix_with_elems( source: &[u8], count: usize, ) -> Result<(&[u8], &Self), ConvertError<AlignmentError<&[u8], Self>, SizeError<&[u8], Self>, ValidityError<&[u8], Self>>>

where Self: KnownLayout<PointerMetadata = usize> + Immutable,

Attempts to interpret the suffix of the given source as a &Self with a DST length equal to count.

fn try_read_from_bytes( source: &[u8], ) -> Result<Self, ConvertError<Infallible, SizeError<&[u8], Self>, ValidityError<&[u8], Self>>>

where Self: Sized,

Attempts to read the given source as a Self.

fn try_read_from_prefix( source: &[u8], ) -> Result<(Self, &[u8]), ConvertError<Infallible, SizeError<&[u8], Self>, ValidityError<&[u8], Self>>>

where Self: Sized,

Attempts to read a Self from the prefix of the given source.

fn try_read_from_suffix( source: &[u8], ) -> Result<(&[u8], Self), ConvertError<Infallible, SizeError<&[u8], Self>, ValidityError<&[u8], Self>>>

where Self: Sized,

Attempts to read a Self from the suffix of the given source.

impl Copy for Cap

impl Immutable for Cap

where u8: Immutable, [u8; 2]: Immutable, le32: Immutable,