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Re: [PATCH 2/3] x86/smpboot: Allow making an INIT IPI conditional

  • To: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
  • From: Roger Pau Monné <roger.pau@xxxxxxxxxx>
  • Date: Tue, 19 Jan 2021 18:20:56 +0100
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On Tue, Jan 19, 2021 at 03:05:38PM +0000, Andrew Cooper wrote:
> On 19/01/2021 14:58, Roger Pau Monné wrote:
> > On Fri, Jan 15, 2021 at 11:10:45PM +0000, Andrew Cooper wrote:
> >> A subsequent change is going to introduce SKINIT support, wherein the APs 
> >> will
> >> be already be in the wait-for-SIPI state, and an INIT must not be sent.
> >>
> >> Introduce a send_INIT boolean, so we can control sending an INIT IPI
> >> separately from sending SIPIs.
> >>
> >> No functional change.
> >>
> >> Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
> > I'm not opposed to introduce this, but maybe it would be better to
> > move it to a separate helper? send_init(unsigned int apicid); or some
> > such?
> >
> > Would reduce one level of indentation.
> I've got a lot of cleanup planned for 4.16, but splitting this up
> INIT-SIPI-SIPI is specifically not one of them.
> This will get more complicated with Intel TXT Intel, and I also want to
> integrate it more nicely with the virtualised AP boot logic.  I suspect
> we'll end up with a function pointer per platform&configuration, but
> that's too much work at this point in 4.15.

Ack, I'm fine with this, albeit I would also be fine with dropping the
variable and just open-coding the ap_boot_method check (but I guess
there will be further use of this variable in newer patches):

Acked-by: Roger Pau Monné <roger.pau@xxxxxxxxxx>

Thanks, Roger.



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