On Wed, Oct 13 2021 at 15:28, Sathyanarayanan Kuppuswamy wrote:
On 10/13/21 2:37 PM, Borislav Petkov wrote:How is that similar?
On Wed, Oct 13, 2021 at 11:25:35PM +0200, Thomas Gleixner wrote:Since in tdx_early_init() all we are going to do is to initialize
So this ends up in doing:Oh, I heartily agree.
use();
init();
Can you spot what's wrong with that?
That's a clear violation of common sense and is simply not going to
happen. Why? If you think about deep defensive programming then use()
will look like this:
use()
{
assert(initialized);
}
which is not something made up. It's a fundamental principle of
programming and some languages enforce that for very good reasons.
Just because it can be done in C is no justification.
What's wrong with:I like simple more than anyone, so sure, I'd prefer that a lot more.
x86_64_start_kernel()
tdx_early_init();
copy_bootdata();
tdx_late_init();
Absolutely nothing. It's clear, simple and well defined.
And so the options parsing would need to happen early using, say,
cmdline_find_option() or so, like sme_enable() does.
"tdx_guest_detected" using cpuid call, shall we name it
tdx_guest_cpuid_init()? (similar to sme_enable call in AMD)
Just chose a name which makes sense in the overall scheme. I surely care
about naming convetions, but what I care more about is correctness.
Whether it ends up being named
tdx_enable() - to match the SME muck
or
tdx_detect()
or whatever makes sense does not really matter. As long as it makes
sense. That's bikeshed painting realm.
Coming back to your suggestion 'tdx_guest_cpuid_init()'. Just sit back
and think about what that name says:
tdx_guest_cpuid_init()
For the uniformed reader this says:
If tdx guest then initialize CPUID
which is obviously not what you want to express, right?
So, naming matters but you are free to chose something which makes
sense.
Thanks,
tglx