Files
punktfunk/packaging/windows/drivers/pf-vdisplay/src/entry.rs
T
enricobuehlerandClaude Fable 5 ab58fd2f0e feat(vdisplay/driver): DDC/CI against the virtual monitor fails fast
In exclusive topology the virtual display is the ONLY monitor on the desktop,
so monitor-control software (the Twinkle Tray / PowerToys PowerDisplay /
Monitorian class) aims its entire DDC traffic — brightness polls,
capabilities-string requests — at OUR monitor. There is no bus and no sink;
the only wrong answer is a slow one (a timeout-shaped failure occupies
win32k's physical-monitor path, serialized per monitor, for its full
duration). Register EvtIddCxMonitorI2CTransmit/Receive and answer every probe
with an immediate STATUS_NOT_SUPPORTED, making the virtual monitor the
cheapest thing on the "bus" to poll. (The receive DDI has no out-arg at the
callback — refusing synchronously refuses the whole transaction.) EDID needs
no equivalent: the OS serves descriptor queries from the blob supplied at
monitor creation without calling the driver.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
2026-07-27 15:37:06 +02:00

155 lines
7.9 KiB
Rust

//! DriverEntry + driver_add — the IddCx device bring-up (STEP 2/3). wdk-build links the UMDF
//! `WdfDriverStubUm` whose `FxDriverEntryUm` forwards to the exported `DriverEntry`. Adapter creation is
//! deferred to the first `EvtDeviceD0Entry` (STEP 3); monitors are created on demand by the control
//! plane (STEP 4). Instrumented with `dbglog!` for on-glass bring-up.
use wdk_iddcx::nt_success;
use wdk_sys::{
GUID, NTSTATUS, PCUNICODE_STRING, PDRIVER_OBJECT, PWDFDEVICE_INIT, ULONG, WDF_DRIVER_CONFIG,
WDF_NO_HANDLE, WDF_NO_OBJECT_ATTRIBUTES, WDF_PNPPOWER_EVENT_CALLBACKS, WDFDEVICE, WDFDRIVER,
call_unsafe_wdf_function_binding, iddcx,
};
use crate::callbacks;
/// A WDF device context, attached to the WDFDEVICE at WdfDeviceCreate. The working virtual-display-rs +
/// oracle both create the device with a context-typed `DeviceContext` (we previously passed
/// WDF_NO_OBJECT_ATTRIBUTES). `WDF_OBJECT_CONTEXT_TYPE_INFO` holds raw pointers (Sync wrapper for the
/// `static`); `UniqueType` self-references per `WDF_DECLARE_CONTEXT_TYPE`.
#[repr(C)]
struct DeviceContext {
_device: WDFDEVICE,
}
#[repr(transparent)]
struct DevCtxInfo(wdk_sys::WDF_OBJECT_CONTEXT_TYPE_INFO);
// SAFETY: immutable 'static type metadata; the inner raw pointers are 'static and never written.
unsafe impl Sync for DevCtxInfo {}
static DEVICE_CTX: DevCtxInfo = DevCtxInfo(wdk_sys::WDF_OBJECT_CONTEXT_TYPE_INFO {
Size: core::mem::size_of::<wdk_sys::WDF_OBJECT_CONTEXT_TYPE_INFO>() as u32,
ContextName: c"PfVdDeviceCtx".as_ptr().cast(),
ContextSize: core::mem::size_of::<DeviceContext>(),
UniqueType: &DEVICE_CTX.0,
EvtDriverGetUniqueContextType: None,
});
#[unsafe(export_name = "DriverEntry")]
pub unsafe extern "system" fn driver_entry(
driver: PDRIVER_OBJECT,
registry_path: PCUNICODE_STRING,
) -> NTSTATUS {
dbglog!("[pf-vd] DriverEntry");
let mut config = pod_init!(WDF_DRIVER_CONFIG);
config.Size = core::mem::size_of::<WDF_DRIVER_CONFIG>() as ULONG;
config.EvtDriverDeviceAdd = Some(driver_add);
// SAFETY: driver + registry_path are loader-provided; config is valid for the call.
let st = unsafe {
call_unsafe_wdf_function_binding!(
WdfDriverCreate,
driver,
registry_path,
WDF_NO_OBJECT_ATTRIBUTES,
&mut config,
WDF_NO_HANDLE.cast::<WDFDRIVER>()
)
};
dbglog!("[pf-vd] WdfDriverCreate -> {st:#x}");
st
}
extern "C" fn driver_add(_driver: WDFDRIVER, mut init: PWDFDEVICE_INIT) -> NTSTATUS {
dbglog!("[pf-vd] driver_add");
// Defer adapter creation to the first D0 entry.
let mut pnp = pod_init!(WDF_PNPPOWER_EVENT_CALLBACKS);
pnp.Size = core::mem::size_of::<WDF_PNPPOWER_EVENT_CALLBACKS>() as ULONG;
pnp.EvtDeviceD0Entry = Some(callbacks::device_d0_entry);
// SAFETY: init is the framework-provided device-init; pnp is valid for the call.
unsafe {
call_unsafe_wdf_function_binding!(WdfDeviceInitSetPnpPowerEventCallbacks, init, &mut pnp);
}
// Build the IddCx client config and wire the SDR callbacks. `.Size` = size_of (1.10 structs, 1.10 fw).
let mut cfg = pod_init!(iddcx::IDD_CX_CLIENT_CONFIG);
cfg.Size = core::mem::size_of::<iddcx::IDD_CX_CLIENT_CONFIG>() as u32;
cfg.EvtIddCxAdapterInitFinished = Some(callbacks::adapter_init_finished);
cfg.EvtIddCxParseMonitorDescription = Some(callbacks::parse_monitor_description);
cfg.EvtIddCxMonitorGetDefaultDescriptionModes = Some(callbacks::monitor_get_default_modes);
cfg.EvtIddCxMonitorQueryTargetModes = Some(callbacks::monitor_query_modes);
cfg.EvtIddCxAdapterCommitModes = Some(callbacks::adapter_commit_modes);
// STEP 7 (HDR): the *2 mode DDIs + the gamma/HDR-metadata/query-target-info callbacks. The adapter
// caps now set CAN_PROCESS_FP16 (adapter.rs), which OBLIGATES this whole set — without them the OS
// rejects the adapter at init ("Failed to get adapter"). The proven oracle (entry.rs) registers the *2
// variants ALONGSIDE the v1 callbacks above (NOT instead of them) — the OS prefers the *2 on IddCx
// 1.10 and falls back to v1 down-level — so we replicate exactly: keep both. The framework no longer
// rejects the *2 set because the FP16 cap is now present (the only reason STEP 3 had to drop them).
cfg.EvtIddCxParseMonitorDescription2 = Some(callbacks::parse_monitor_description2);
cfg.EvtIddCxMonitorQueryTargetModes2 = Some(callbacks::monitor_query_modes2);
cfg.EvtIddCxAdapterCommitModes2 = Some(callbacks::adapter_commit_modes2);
cfg.EvtIddCxAdapterQueryTargetInfo = Some(callbacks::query_target_info);
cfg.EvtIddCxMonitorSetDefaultHdrMetaData = Some(callbacks::set_default_hdr_metadata);
cfg.EvtIddCxMonitorSetGammaRamp = Some(callbacks::set_gamma_ramp);
cfg.EvtIddCxMonitorAssignSwapChain = Some(callbacks::assign_swap_chain);
cfg.EvtIddCxMonitorUnassignSwapChain = Some(callbacks::unassign_swap_chain);
// DDC fail-fast (stall-immunity): monitor-control software polls the virtual monitor's DDC —
// in exclusive topology it is the ONLY monitor. These answer every probe with an immediate
// STATUS_NOT_SUPPORTED instead of whatever slow path an unregistered interface takes.
cfg.EvtIddCxMonitorI2CTransmit = Some(callbacks::monitor_i2c_transmit);
cfg.EvtIddCxMonitorI2CReceive = Some(callbacks::monitor_i2c_receive);
cfg.EvtIddCxDeviceIoControl = Some(callbacks::device_io_control);
// SAFETY: init is the framework device-init; cfg is fully populated + sized. (Links IddCxStub.)
let status = unsafe { wdk_iddcx::IddCxDeviceInitConfig(init, &cfg) };
dbglog!("[pf-vd] IddCxDeviceInitConfig -> {status:#x}");
if !nt_success(status) {
return status;
}
let mut device: WDFDEVICE = core::ptr::null_mut();
// Attach a device context type (like the working virtual-display-rs/oracle), not WDF_NO_OBJECT_ATTRIBUTES.
let mut dev_attr = pod_init!(wdk_sys::WDF_OBJECT_ATTRIBUTES);
dev_attr.Size = core::mem::size_of::<wdk_sys::WDF_OBJECT_ATTRIBUTES>() as u32;
dev_attr.ExecutionLevel = wdk_sys::_WDF_EXECUTION_LEVEL::WdfExecutionLevelInheritFromParent;
dev_attr.SynchronizationScope =
wdk_sys::_WDF_SYNCHRONIZATION_SCOPE::WdfSynchronizationScopeInheritFromParent;
dev_attr.ContextTypeInfo = &DEVICE_CTX.0;
// Drop every monitor's swap-chain worker when the device is removed (PnP / unload), so the worker
// threads don't linger into teardown (E1 device cleanup). IddCx-free; see callbacks::device_cleanup.
dev_attr.EvtCleanupCallback = Some(callbacks::device_cleanup);
// SAFETY: init configured above; dev_attr is a valid context-typed attributes block.
let status = unsafe {
call_unsafe_wdf_function_binding!(WdfDeviceCreate, &mut init, &mut dev_attr, &mut device)
};
dbglog!("[pf-vd] WdfDeviceCreate -> {status:#x}");
if !nt_success(status) {
return status;
}
// SAFETY: device is the just-created WDFDEVICE.
let status = unsafe { wdk_iddcx::IddCxDeviceInitialize(device) };
dbglog!("[pf-vd] IddCxDeviceInitialize -> {status:#x}");
if !nt_success(status) {
return status;
}
// Expose the owned pf-vdisplay control interface: the host opens this GUID and drives the proto control
// plane (IOCTL_ADD/REMOVE/PING/…) which arrives at EvtIddCxDeviceIoControl. NOT SudoVDA's GUID. (The
// upstream uses a socket instead, so it has no interface; ours is IOCTL-based.)
let (d1, d2, d3, d4) = pf_driver_proto::interface_guid_fields();
let guid = GUID {
Data1: d1,
Data2: d2,
Data3: d3,
Data4: d4,
};
// SAFETY: device is the just-created WDFDEVICE; guid lives for the call; no reference string.
let status = unsafe {
call_unsafe_wdf_function_binding!(
WdfDeviceCreateDeviceInterface,
device,
&guid,
core::ptr::null()
)
};
dbglog!("[pf-vd] WdfDeviceCreateDeviceInterface -> {status:#x}");
status
}