Struct MsixEmulator 

pub struct MsixEmulator { /* private fields */ }

Emulator for the hardware-level interface required to configure and trigger MSI-X interrupts on a PCI device.

Implementations

impl MsixEmulator

pub fn new( bar: u8, count: u16, msi_target: &MsiTarget, ) -> (Self, impl PciCapability + use<>)

Create a new MsixEmulator instance, along with with its associated PciCapability structure.

This implementation of MSI-X expects a dedicated BAR to store the vector and pending tables.

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DEVNOTE: This current implementation of MSI-X isn’t particularly “flexible” with respect to the various ways the PCI spec allows MSI-X to be implemented. e.g: it uses a shared BAR for the table and BPA, with fixed offsets into the BAR for both of those tables. It would be nice to re-visit this code and make it more flexible.

pub fn bar_len(&self) -> u64

Return the total length of the MSI-X BAR (Actually, the notion that there is an “MSI-X BAR” is an issue to fix sometime. MSI-X tables are often in the same bar as other things.)

pub fn read_u32(&self, offset: u64) -> u32

Read a u32 from the MSI-X BAR at the given offset.

pub fn write_u32(&mut self, offset: u64, val: u32)

Write a u32 to the MSI-X BAR at the given offset.

pub fn interrupt(&self, index: u16) -> Option<Interrupt>

Return an [Interrupt] associated with the particular MSI-X vector, or None if the index is out of bounds.

pub fn set_pending_bit(&self, index: u16)

Sets the pending bit for the given vector index.

Used by device passthrough (e.g., VFIO with irqfd) to record that an interrupt arrived while the vector was masked, so PBA reads return the correct pending state.

pub fn enable_irqfd( &self, irqfd: &dyn IrqFd, register: impl FnOnce(&[&Event]) -> Result<()>, ) -> Result<()>

Enable kernel-mediated interrupt delivery for all vectors.

Creates one irqfd route per vector using the provided [IrqFd] interface. The register callback receives references to the events for all vectors. The caller uses this to pass events to the interrupt source (e.g., VFIO map_msix or vhost-user SET_VRING_CALL). After the callback returns, the routes are installed in the emulator. When the guest programs MSI-X table entries, the emulator automatically updates the kernel’s MSI routing.

Call disable_irqfd to tear down the routes.

pub fn disable_irqfd(&self)

Tear down kernel-mediated interrupt delivery.

Drops all irqfd routes, unregistering them from the hypervisor and freeing GSI allocations.

Trait Implementations

impl Clone for MsixEmulator

fn clone(&self) -> MsixEmulator

Returns a duplicate of the value.

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

Performs copy-assignment from source.