Re: [PATCH v5 2/3] x86/boot: Introduce the kernel_info.setup_type_max

From: Borislav Petkov <bp@alien8.de>
To: Daniel Kiper <daniel.kiper@oracle.com>
Cc: linux-efi@vger.kernel.org, linux-kernel@vger.kernel.org,
	x86@kernel.org, xen-devel@lists.xenproject.org,
	ard.biesheuvel@linaro.org, boris.ostrovsky@oracle.com,
	corbet@lwn.net, dave.hansen@linux.intel.com, luto@kernel.org,
	peterz@infradead.org, eric.snowberg@oracle.com, hpa@zytor.com,
	jgross@suse.com, kanth.ghatraju@oracle.com,
	konrad.wilk@oracle.com, mingo@redhat.com, rdunlap@infradead.org,
	ross.philipson@oracle.com, tglx@linutronix.de
Subject: Re: [PATCH v5 2/3] x86/boot: Introduce the kernel_info.setup_type_max
Date: Fri, 8 Nov 2019 11:09:30 +0100	[thread overview]
Message-ID: <20191108100930.GA4503@zn.tnic> (raw)
In-Reply-To: <20191104151354.28145-3-daniel.kiper@oracle.com>

On Mon, Nov 04, 2019 at 04:13:53PM +0100, Daniel Kiper wrote:
> This field contains maximal allowed type for setup_data.
> 
> This patch does not bump setup_header version in arch/x86/boot/header.S
> because it will be followed by additional changes coming into the
> Linux/x86 boot protocol.
> 
> Suggested-by: H. Peter Anvin (Intel) <hpa@zytor.com>
> Signed-off-by: Daniel Kiper <daniel.kiper@oracle.com>
> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
> Reviewed-by: Ross Philipson <ross.philipson@oracle.com>
> Reviewed-by: H. Peter Anvin (Intel) <hpa@zytor.com>
> ---
> v5 - suggestions/fixes:
>    - move incorrect references to the setup_indirect to the
>      patch introducing it,
>    - do not bump setup_header version in arch/x86/boot/header.S
>      (suggested by H. Peter Anvin).
> ---
>  Documentation/x86/boot.rst             | 9 ++++++++-
>  arch/x86/boot/compressed/kernel_info.S | 5 +++++
>  arch/x86/include/uapi/asm/bootparam.h  | 3 +++
>  3 files changed, 16 insertions(+), 1 deletion(-)
> 
> diff --git a/Documentation/x86/boot.rst b/Documentation/x86/boot.rst
> index c60fafda9427..1dad6eee8a5c 100644
> --- a/Documentation/x86/boot.rst
> +++ b/Documentation/x86/boot.rst
> @@ -73,7 +73,7 @@ Protocol 2.14:	BURNT BY INCORRECT COMMIT ae7e1238e68f2a472a125673ab506d49158c188
>  		(x86/boot: Add ACPI RSDP address to setup_header)
>  		DO NOT USE!!! ASSUME SAME AS 2.13.
>  
> -Protocol 2.15:	(Kernel 5.5) Added the kernel_info.
> +Protocol 2.15:	(Kernel 5.5) Added the kernel_info and kernel_info.setup_type_max.
>  =============	============================================================
>  
>  .. note::
> @@ -981,6 +981,13 @@ Offset/size:	0x0008/4
>    This field contains the size of the kernel_info including kernel_info.header
>    and kernel_info.kernel_info_var_len_data.
>  
> +============	==============
> +Field name:	setup_type_max
> +Offset/size:	0x0008/4

You already have

Field name:     size_total
Offset/size:    0x0008/4

at that offset.

I guess you mean setup_type_max's offset to be 0x000c and it would be
that member:

.long   0x01234567      /* Some fixed size data for the bootloaders. */

?

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette