Re: [PATCH 1/3] x86: slightly re-arrange 32-bit handling in dom0_construct_pv()

[Jan Beulich <jbeulich@xxxxxxxx>]

On 06.08.2020 16:04, Andrew Cooper wrote:
> On 06/08/2020 10:28, Jan Beulich wrote:
>> Add #ifdef-s (the 2nd one will be needed in particular, to guard the
>> uses of m2p_compat_vstart and HYPERVISOR_COMPAT_VIRT_START()) and fold
>> duplicate uses of elf_32bit().
>>
>> Also adjust what gets logged: Avoid "compat32" when support isn't built
>> in, and don't assume ELF class <> ELFCLASS64 means ELFCLASS32.
>>
>> Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
> 
> Acked-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx> although with some
> further suggestions.

Thanks.

>> @@ -357,27 +356,36 @@ int __init dom0_construct_pv(struct doma
>>          goto out;
>>  
>>      /* compatibility check */
>> +    printk(" Xen  kernel: 64-bit, lsb%s\n",
>> +           IS_ENABLED(CONFIG_PV32) ? ", compat32" : "");
> 
> Here, and below, we print out lsb/msb for the ELF file.  However, we
> don't use or check that it is actually lsb, and blindly assume that it is.
> 
> Why bother printing it then?

To be honest, I'd rather add a check than drop the printing.
However unlikely it may be to encounter an MSB ELF binary ...
This particular one I'd like to do in a separate, follow-on
patch though.

I've addressed the other comments in what I intend to commit.

Jan