Struct devices::PciVirtualConfigMmio

pub struct PciVirtualConfigMmio {
    pci_root: Arc<Mutex<PciRoot>>,
    register_bit_num: usize,
}

Inspired by PCI configuration space, CrosVM provides 2048 dword virtual registers (8KiB in total) for each PCI device. The guest can use these registers to exchange device-specific information with crosvm. The first 4kB is trapped by crosvm and crosvm supplies these register’s emulation. The second 4KB is mapped into guest directly as shared memory, so when guest access this 4KB, vm exit doesn’t happen. All these virtual registers from all PCI devices locate in a contiguous memory region. The base address of this memory region is provided by an IntObj named VCFG in the ACPI DSDT. Bit 12 is used to select the first trapped page or the second directly mapped page The offset of each register is calculated in the same way as PCIe ECAM; i.e. offset = (bus << 21) | (device << 16) | (function << 13) | (page_select << 12) | (register_index << 2)

Fields

pci_root: Arc<Mutex<PciRoot>>

PCI root bridge.

register_bit_num: usize

Register bit number in config address.

Implementations

impl PciVirtualConfigMmio

pub fn new(pci_root: Arc<Mutex<PciRoot>>, register_bit_num: usize) -> Self

Trait Implementations

impl BusDevice for PciVirtualConfigMmio

fn debug_label(&self) -> String

Returns a label suitable for debug output.

fn device_id(&self) -> DeviceId

Returns a unique id per device type suitable for metrics gathering.

fn read(&mut self, info: BusAccessInfo, data: &mut [u8])

Reads at offset from this device

fn write(&mut self, info: BusAccessInfo, data: &[u8])

Writes at offset into this device

fn config_register_write( &mut self, reg_idx: usize, offset: u64, data: &[u8] ) -> ConfigWriteResult

Sets a register in the configuration space. Only used by PCI.

fn config_register_read(&self, reg_idx: usize) -> u32

Gets a register from the configuration space. Only used by PCI.

fn init_pci_config_mapping( &mut self, shmem: &SharedMemory, base: usize, len: usize ) -> bool

Provides a memory region to back MMIO access to the configuration space. If the device can keep the memory region up to date, then it should return true, after which no more calls to config_register_read will be made. Otherwise the device should return false.

fn virtual_config_register_write(&mut self, reg_idx: usize, value: u32)

Sets a register in the virtual config space. Only used by PCI.

fn virtual_config_register_read(&self, reg_idx: usize) -> u32

Gets a register from the virtual config space. Only used by PCI.

fn on_sandboxed(&mut self)

Invoked when the device is sandboxed.

fn get_ranges(&self) -> Vec<(BusRange, BusType)>

Gets a list of all ranges registered by this BusDevice.

fn destroy_device(&mut self)

Invoked when the device is destroyed

fn is_bridge(&self) -> Option<u8>

Returns the secondary bus number if this bus device is pci bridge

impl Suspendable for PciVirtualConfigMmio

fn sleep(&mut self) -> Result<()>

Stop all threads related to the device. Sleep should be idempotent.

fn wake(&mut self) -> Result<()>

Create/Resume all threads related to the device. Wake should be idempotent.

fn snapshot(&mut self) -> Result<Value>

Save the device state in an image that can be restored.

fn restore(&mut self, data: Value) -> Result<()>

Load a saved snapshot of an image.