RE: [PATCH] x86/efi: Restore Firmware IDT in before ExitBootServices()

[David Laight]

From: 'Joerg Roedel'
> Sent: 20 August 2021 09:52
> 
> On Fri, Aug 20, 2021 at 08:43:47AM +0000, David Laight wrote:
> > Hmmm...
> > If Linux needs its own IDT then temporarily substituting the old IDT
> > prior to a UEFI call will cause 'grief' if a 'Linux' interrupt
> > happens during the UEFI call.
> 
> This is neede only during very early boot before Linux called
> ExitBootServices(). Nothing that causes IRQs is set up by Linux yet. Of
> course the Firmware could have set something up, but Linux runs with
> IRQs disabled when on its own IDT at that stage.

So allocate and initialise the Linux IDT - so entries can be added.
But don't execute 'lidt' until later on.

	David

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