Re: [PATCH] x86/microcode/AMD: Increase microcode PATCH_MAX_SIZE

[Jiri Slaby]

On 20. 07. 23, 22:28, John Allen wrote:
> Future AMD cpus will have microcode patches that exceed the current
> limit of three 4K pages. Increase substantially to avoid future size
> increases.

Hi,

so with my current distro (openSUSE TW):
$ zgrep NODES_SHIFT /proc/config.gz
CONFIG_NODES_SHIFT=10

This:

static u8 amd_ucode_patch[MAX_NUMNODES][PATCH_MAX_SIZE];

is now 32M instead of 12M. That is a complete waste on my _one_ node 
system. Can we make amd_ucode_patch dynamic first, depending on 
num_online_nodes()?

> Signed-off-by: John Allen <john.allen@xxxxxxx>
> Cc: stable@xxxxxxxxxxxxxxx
> ---
>   arch/x86/include/asm/microcode_amd.h | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/x86/include/asm/microcode_amd.h b/arch/x86/include/asm/microcode_amd.h
> index e6662adf3af4..e3d5f5ae2f46 100644
> --- a/arch/x86/include/asm/microcode_amd.h
> +++ b/arch/x86/include/asm/microcode_amd.h
> @@ -41,7 +41,7 @@ struct microcode_amd {
>   	unsigned int			mpb[];
>   };
>   
> -#define PATCH_MAX_SIZE (3 * PAGE_SIZE)
> +#define PATCH_MAX_SIZE (8 * PAGE_SIZE)
>   
>   #ifdef CONFIG_MICROCODE_AMD
>   extern void __init load_ucode_amd_bsp(unsigned int family);

thanks,
--
js
suse labs