Re: [PATCH v5 1/7] x86/kexec: Consolidate relocate_kernel() function parameters

["Huang, Kai" <kai.huang@intel.com>]

On Tue, 2025-07-29 at 00:28 +1200, Kai Huang wrote:
> During kexec, the kernel jumps to the new kernel in relocate_kernel(),
> which is implemented in assembly and both 32-bit and 64-bit have their
> own version.
> 
> Currently, for both 32-bit and 64-bit, the last two parameters of the
> relocate_kernel() are both 'unsigned int' but actually they only convey
> a boolean, i.e., one bit information.  The 'unsigned int' has enough
> space to carry two bits information therefore there's no need to pass
> the two booleans in two separate 'unsigned int'.
> 
> Consolidate the last two function parameters of relocate_kernel() into a
> single 'unsigned int' and pass flags instead.
> 
> Only consolidate the 64-bit version albeit the similar optimization can
> be done for the 32-bit version too.  Don't bother changing the 32-bit
> version while it is working (since assembly code change is required).
> 
> Signed-off-by: Kai Huang <kai.huang@intel.com>
> ---
> 
>  v4 -> v5:
>   - RELOC_KERNEL_HOST_MEM_ACTIVE -> RELOC_KERNEL_HOST_MEM_ENC_ACTIVE
>     (Tom)
>   - Add a comment to explain only RELOC_KERNEL_PRESERVE_CONTEXT is
>     restored after jumping back from peer kernel for preserved_context
>     kexec (pointed out by Tom).
>   - Use testb instead of testq when comparing the flag with R11 to save
>     3 bytes (Hpa).
> 
> 

Hi Tom,

Wondering do you have more comments?  Thanks.