Messages in this thread | | | Date | Fri, 9 Mar 2018 12:11:57 +0100 | From | Borislav Petkov <> | Subject | Re: [PATCH V2 2/3] efi: Introduce efi_rts_workqueue and some infrastructure to invoke all efi_runtime_services() |
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On Fri, Mar 09, 2018 at 02:37:59AM +0000, Prakhya, Sai Praneeth wrote: > But, I guess, we have some downsides with this design: > 1. We are doing this to have "no exceptions to use efi_rts_wq", but we will be making > the common case complicated. i.e. When a user requests to write some efi variable,
So if the pstore use case is so important and special, I think we should make the EFI path as fast as possible as getting that data to the pstore is a priority.
> Alternatively, instead of playing around with in_atomic(), we could have wrapper > functions like efi_write_var_non_wq() which will only be used by pstore. This function > will not use efi_rts_wq and directly invoke efi_runtime_service. Just an attempt to > make the code not look messy.
I guess.
If the write-to-pstore case is such a critical one, I guess the exception is justified.
> That's true! AFAIK, we don't have any issues handling NMI while in efi_pgd. > We might have issues only when, we are already in efi_pgd, NMI comes along
Can you trigger this? Or is it something hypothetical?
> and NMI handler tries to touch the regions that are not mapped in efi_pgd
If it is not hypothetical, the NMI handler should learn to look at CR3 first and return if CR3 has the efi pgd.
-- Regards/Gruss, Boris.
Good mailing practices for 400: avoid top-posting and trim the reply.
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