On Wed, 15 Jan 2025 at 15:58, James Bottomley <James.Bottomley@xxxxxxxxxxxxxxxxxxxxx> wrote: > > On Wed, 2025-01-15 at 22:49 +0800, Weizhao Ouyang wrote: > > On Wed, Jan 15, 2025 at 10:34 PM James Bottomley > > <James.Bottomley@xxxxxxxxxxxxxxxxxxxxx> wrote: > > > > > > On Wed, 2025-01-15 at 22:14 +0800, Weizhao Ouyang wrote: > > > > Currently, when setting efi variables through the runtime > > > > service, efivarfs cannot sync variable updates properly. > > > > Introduce efivarfs refresh remount to support efivarfs > > > > information updates from other sources. > > > > > > What other sources could there possibly be? While the Linux kernel > > > has sole possession of the EFI RT interface after ExitBootServices > > > has been called, nothing else should be able to update the > > > variables except efivarfs. This is a guarantee from UEFI so why do > > > you think we can't rely on it? > > > > One route that may exist is: drivers/firmware/efi/test/efi_test.c > > holds some ioctls to call runtime service. > > That's not supposed to be used for anything other than direct testing > using the firmware test suite, which shouldn't impact production use of > efivarfs because it's defined to be N in Kconfig. However, if we > suddenly decided there was a use case for production systems running > the test suite, the way forwards would be a notifier that tells > efivarfs about successful updates to variables as they occur without > having to remount. > I'd argue that running efi_test while efivarfs is mounted renders your test results useless, and so there is no need to make them play nicely together.
