> Adopt Access Control Services (ACS) controls on all incoming preserved > devices (endpoints and upstream bridges) during a Live Update. > > Inheriting ACS flags avoids changing routing rules while memory > transactions are in flight from preserved devices. This is also strictly > necessary to ensure that IOMMU group assignments do not change during or > after Live Update. > > The adopted controls are recorded by the pci_save_state() call in > pci_bus_add_device(), which runs before drivers bind, so they are > automatically reapplied by pci_restore_state() if the device is reset. > If that save buffer could not be allocated there is nowhere to record > the adopted controls, and they would be silently lost by the first > reset. Program ACS from scratch in that case, which is a better outcome > than leaving ACS disabled. > > To simplify ACS inheritance, reject preserving any devices that require > quirks to enable ACS as those quirks would also have to take Live Update > into account. > > Signed-off-by: David Matlack <[email protected]>
Sashiko has reviewed this patch and found no issues. It looks great! -- Sashiko AI review ยท https://sashiko.dev/#/patchset/[email protected]?part=9
