VFIO PCI variant drivers will use reset_prepare() and reset_done() to forward PCI reset notifications to their VFIO registration.
Adding these callbacks to pci::Driver lets VFIO variants reuse the PCI adapter's reset callback dispatch. A following patch removes the duplicate vfio::pci::Adapter. Because there is no gurantee that drvdata must be valid when reset is issued, using callback_data_with which contains the helper to null-check drv_data, this could occur during probe if reset is called before set_drvdata Suggested-by: Zhi Wang <[email protected]> Signed-off-by: Simon Song <[email protected]> --- rust/kernel/pci.rs | 70 +++++++++++++++++++++++++++++++++++++++++ rust/kernel/vfio/pci.rs | 12 +++++++ 2 files changed, 82 insertions(+) diff --git a/rust/kernel/pci.rs b/rust/kernel/pci.rs index a156927e23d..adc7e92d44e 100644 --- a/rust/kernel/pci.rs +++ b/rust/kernel/pci.rs @@ -109,6 +109,9 @@ unsafe fn register( (*pdrv.get()).remove = Some(Self::remove_callback); (*pdrv.get()).id_table = T::ID_TABLE.as_ptr(); (*pdrv.get()).driver_managed_dma = T::DRIVER_MANAGED_DMA; + if T::HAS_RESET_PREPARE || T::HAS_RESET_DONE { + (*pdrv.get()).err_handler = &Self::ERROR_HANDLERS; + } #[cfg(CONFIG_PCI_IOV)] if T::HAS_SRIOV_ENABLE { (*pdrv.get()).sriov_configure = Some(Self::sriov_configure_callback); @@ -175,6 +178,61 @@ extern "C" fn remove_callback(pdev: *mut bindings::pci_dev) { // Drop private data before returning to PCI core, while its removal context is valid. drop(data); } + + /// # Safety + /// + /// `dev` must belong to `T`. Any installed driver data must remain installed until this + /// call returns. The data lifetime is independent of the callback borrow. + unsafe fn callback_data_with<R>( + dev: *mut bindings::device, + f: impl for<'borrow, 'data> FnOnce(Pin<&'borrow T::Data<'data>>) -> R, + ) -> Option<R> { + // SAFETY: The callback supplies a device bound to `T`. + let data = unsafe { bindings::dev_get_drvdata(dev) }; + if data.is_null() { + return None; + } + // SAFETY: PCI installed pinned `T::Data`; the caller excludes its removal. + Some(f(unsafe { + Pin::new_unchecked(&*data.cast::<T::Data<'_>>()) + })) + } + + extern "C" fn reset_prepare_callback(pdev: *mut bindings::pci_dev) { + // SAFETY: PCI holds the device lock throughout reset. + let dev = unsafe { &*pdev.cast::<Device<device::CoreInternal<'_>>>() }; + // SAFETY: The device lock prevents removal of installed driver data. + let _ = unsafe { + Self::callback_data_with(&raw mut (*pdev).dev, |data| T::reset_prepare(dev, data)) + }; + } + + extern "C" fn reset_done_callback(pdev: *mut bindings::pci_dev) { + // SAFETY: PCI holds the device lock throughout reset. + let dev = unsafe { &*pdev.cast::<Device<device::CoreInternal<'_>>>() }; + // SAFETY: The device lock prevents removal of installed driver data. + let _ = unsafe { + Self::callback_data_with(&raw mut (*pdev).dev, |data| T::reset_done(dev, data)) + }; + } + + const ERROR_HANDLERS: bindings::pci_error_handlers = bindings::pci_error_handlers { + error_detected: None, + mmio_enabled: None, + slot_reset: None, + reset_prepare: if T::HAS_RESET_PREPARE { + Some(Self::reset_prepare_callback) + } else { + None + }, + reset_done: if T::HAS_RESET_DONE { + Some(Self::reset_done_callback) + } else { + None + }, + resume: None, + cor_error_detected: None, + }; } /// Declares a kernel module that exposes a single PCI driver. @@ -375,6 +433,18 @@ fn unbind<'bound>(dev: &'bound Device<device::Core<'_>>, this: Pin<&Self::Data<' let _ = (dev, this); } + /// Called before a PCI function reset, with the device lock held. + fn reset_prepare<'bound>(dev: &Device<device::Core<'_>>, this: Pin<&Self::Data<'bound>>) { + let _ = (dev, this); + build_error!(crate::error::VTABLE_DEFAULT_ERROR) + } + + /// Called after a PCI function reset, with the device lock held. + fn reset_done<'bound>(dev: &Device<device::Core<'_>>, this: Pin<&Self::Data<'bound>>) { + let _ = (dev, this); + build_error!(crate::error::VTABLE_DEFAULT_ERROR) + } + /// Enables Single Root I/O Virtualization (SR-IOV) for a PF. /// /// Called when userspace writes a nonzero VF count to `sriov_numvfs`. The token carries the diff --git a/rust/kernel/vfio/pci.rs b/rust/kernel/vfio/pci.rs index 43c14b4e3a1..db30dbce6a8 100644 --- a/rust/kernel/vfio/pci.rs +++ b/rust/kernel/vfio/pci.rs @@ -1084,6 +1084,18 @@ unsafe fn unregister(&self) { // VGA and runtime PM callbacks. No field of the enclosing data is being destroyed. unsafe { bindings::vfio_pci_core_unregister_device(self.dev.core_device()) }; } + + /// Prepare the variant driver's state for a PCI reset. + pub fn reset_prepare(&self) { + // SAFETY: This owner keeps the pinned registration data alive. + unsafe { self.dev.registration_data_with(T::reset_prepare) }; + } + + /// Complete the variant driver's state update after a PCI reset. + pub fn reset_done(&self) -> Result { + // SAFETY: This owner keeps the pinned registration data alive. + unsafe { self.dev.registration_data_with(T::reset_done) } + } } impl<T: Operations> Drop for Registration<'_, T> { -- 2.43.7
