linux-kernel - Re: [PATCH] Map in physical addresses in efi_map_region

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Message-ID: <20160815124258.GF30909@codeblueprint.co.uk>
Date:	Mon, 15 Aug 2016 13:42:58 +0100
From:	Matt Fleming <matt@...eblueprint.co.uk>
To:	Alex Thorlton <athorlton@....com>
Cc:	linux-kernel@...r.kernel.org, Russ Anderson <rja@....com>,
	Dimitri Sivanich <sivanich@....com>,
	Mike Travis <travis@....com>,
	Thomas Gleixner <tglx@...utronix.de>,
	Ingo Molnar <mingo@...hat.com>,
	"H. Peter Anvin" <hpa@...or.com>, x86@...nel.org,
	linux-efi@...r.kernel.org, Dave Young <dyoung@...hat.com>,
	Borislav Petkov <bp@...en8.de>
Subject: Re: [PATCH] Map in physical addresses in efi_map_region_fixed

(Cc'ing Boris and Dave)

On Fri, 05 Aug, at 06:59:35PM, Alex Thorlton wrote:
> This is a simple change to add in the physical mappings as well as the
> virtual mappings in efi_map_region_fixed.  The motivation here is to
> get access to EFI runtime code that is only available via the 1:1
> mappings on a kexec'd kernel.
> 
> The added call is essentially the kexec analog of the first __map_region
> that Boris put in efi_map_region in commit d2f7cbe7b26a ("x86/efi:
> Runtime services virtual mapping").
> 
> Signed-off-by: Alex Thorlton <athorlton@....com>
> Cc: Russ Anderson <rja@....com>
> Cc: Dimitri Sivanich <sivanich@....com>
> Cc: Mike Travis <travis@....com>
> Cc: Matt Fleming <matt@...eblueprint.co.uk>
> Cc: Thomas Gleixner <tglx@...utronix.de>
> Cc: Ingo Molnar <mingo@...hat.com>
> Cc: "H. Peter Anvin" <hpa@...or.com>
> Cc: x86@...nel.org
> Cc: linux-efi@...r.kernel.org
> ---
>  arch/x86/platform/efi/efi_64.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/arch/x86/platform/efi/efi_64.c b/arch/x86/platform/efi/efi_64.c
> index 459bcbb..b206126 100644
> --- a/arch/x86/platform/efi/efi_64.c
> +++ b/arch/x86/platform/efi/efi_64.c
> @@ -363,6 +363,7 @@ void __init efi_map_region(efi_memory_desc_t *md)
>   */
>  void __init efi_map_region_fixed(efi_memory_desc_t *md)
>  {
> +	__map_region(md, md->phys_addr);
>  	__map_region(md, md->virt_addr);
>  }
>  

This looks fine to me. I'm going to run it through my tests and unless
anyone complains, apply it for v4.9.