Re: [PATCH v5 05/10] x86, efi: Add efi_fake_mem support for EFI_MEMORY_SP

From: Ingo Molnar
Date: Tue Sep 10 2019 - 02:48:34 EST



* Dan Williams <dan.j.williams@xxxxxxxxx> wrote:

> Given that EFI_MEMORY_SP is platform BIOS policy descision for marking
> memory ranges as "reserved for a specific purpose" there will inevitably
> be scenarios where the BIOS omits the attribute in situations where it
> is desired. Unlike other attributes if the OS wants to reserve this
> memory from the kernel the reservation needs to happen early in init. So
> early, in fact, that it needs to happen before e820__memblock_setup()
> which is a pre-requisite for efi_fake_memmap() that wants to allocate
> memory for the updated table.
>
> Introduce an x86 specific efi_fake_memmap_early() that can search for
> attempts to set EFI_MEMORY_SP via efi_fake_mem and update the e820 table
> accordingly.
>
> The KASLR code that scans the command line looking for user-directed
> memory reservations also needs to be updated to consider
> "efi_fake_mem=nn@ss:0x40000" requests.
>
> Cc: <x86@xxxxxxxxxx>
> Cc: Borislav Petkov <bp@xxxxxxxxx>
> Cc: Ingo Molnar <mingo@xxxxxxxxxx>
> Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> Cc: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>
> Reviewed-by: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
> Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>

A couple of these patches are touching EFI code, but only the first one
carries a Reviewed-by from Ard.

Ard, are these patches and the whole series fine with you?

Thanks,

Ingo