Re: [Minios-devel] [UNIKRAFT PATCHv3 5/7] plat/common: Find and register IRQ for arch_timer

["Justin He (Arm Technology China)" <Justin.He@xxxxxxx>]

Hi Julien

> -----Original Message-----
> From: Julien Grall <julien.grall@xxxxxxx>
> Sent: 2019年9月17日 16:39
> To: Justin He (Arm Technology China) <Justin.He@xxxxxxx>; Santiago
> Pagani <Santiago.Pagani@xxxxxxxxx>; minios-devel@xxxxxxxxxxxxxxxxxxxx;
> Simon Kuenzer <simon.kuenzer@xxxxxxxxx>; Sharan Santhanam
> <Sharan.Santhanam@xxxxxxxxx>
> Cc: Kaly Xin (Arm Technology China) <Kaly.Xin@xxxxxxx>; Wei Chen (Arm
> Technology China) <Wei.Chen@xxxxxxx>; Jianyong Wu (Arm Technology
> China) <Jianyong.Wu@xxxxxxx>; nd <nd@xxxxxxx>
> Subject: Re: [UNIKRAFT PATCHv3 5/7] plat/common: Find and register IRQ
> for arch_timer
> 
> On 9/17/19 8:01 AM, Justin He (Arm Technology China) wrote:
> > Hi Julien (welcome back from holiday 😊 )
> 
> Hi,
> 
> Thanks :).
> 
> >> -----Original Message-----
> >> From: Julien Grall <julien.grall@xxxxxxx>
> >> Sent: 2019年9月17日 3:53
> >> To: Justin He (Arm Technology China) <Justin.He@xxxxxxx>; Santiago
> >> Pagani <Santiago.Pagani@xxxxxxxxx>; minios-devel@xxxxxxxxxxxxxxxxxxxx;
> >> Simon Kuenzer <simon.kuenzer@xxxxxxxxx>; Sharan Santhanam
> >> <Sharan.Santhanam@xxxxxxxxx>
> >> Cc: Kaly Xin (Arm Technology China) <Kaly.Xin@xxxxxxx>; Wei Chen
> (Arm
> >> Technology China) <Wei.Chen@xxxxxxx>; Jianyong Wu (Arm
> Technology
> >> China) <Jianyong.Wu@xxxxxxx>
> >> Subject: Re: [UNIKRAFT PATCHv3 5/7] plat/common: Find and register
> IRQ
> >> for arch_timer
> >>
> >> On 9/16/19 8:52 AM, Justin He (Arm Technology China) wrote:
> >>> Hi  Santiago
> >>
> >> Hi all,
> >>
> >> @Santiago, it is quite difficult to follow the thread when you start
> >> your answer with "COMMENT". May I ask you to configure your e-mail
> >> client to quote properly (i.e >)?
> >>
> >> Furthermore, disclaimer footer should be avoided on the mailing list.
> >> You are basically saying this is confidential but you send to everyone
> >> (mailing list are archived)...
> > OK
> 
> It wasn't directed to you ;).
> 
> >>
> >> [...]
> >>
> >>>> COMMENT: There is nothing that we would like to do here? Not even
> >>>> disable the IRQ? As the timer is not stopped, when the counter
> >> overflows
> >>>> we would get a new interrupt otherwise (although the overflow could
> >>>> happen in a very very long time, right?)
> >>>
> >>> In previous version, we added a generic_timer_mask_irq() in
> >>> generic_timer_irq_handler. But as per the suggestion [1] from Julien,
> we
> >>> removed it. Besides, we referred to the minios logic at [2], it only 
> >>> called
> >>> unmask and mask in block_domain (which is equivalent to unikraft's
> >>> generic_timer_cpu_block)
> >>
> >> Looking at my comments again, I am not sure where I suggested to
> remove
> >> generic_timer_mask_irq()... Can you expand it?
> > Okay... sorry for my mistakes. I will add generic_timer_mask_irq() back.
> >>
> >> FWIW, the two main comments on the previous versions were:
> >>      1) isb() should be added after updating the system register to
> >> ensure that the system system is synchronized
> >>      2) This is common code between arm32 and arm64. But the system
> >> register name are arm64... Accesses should be stub in arch-specific
> >> header so the code can work for both arm32 and arm64.
> > I renamed plat/common/arm/time.c to plat/common/arm/time_arm64.c
> > Seems that is not enough for you?  If no, I have no objections to make
> > a stub  for arm32.
> 
> Well, the only bits arm64 specifics in this file are the access to the
> system registers. So renaming to time_arm64.c seems a bit overkill...
> 
> If there are plan to make arm32 a correct port on Unikraft, then
> splitting the code would be the best. If there are no plan to get arm32,
> then maybe you should think of killing it completely.

Arm32 xen plat is initially supported but no one  has touched that for a long
time. Currently let’s focus on arm64 kvm plat only. If the requirements 
changes, 
we can support arm32 additionally. What do you think about it?


--
Cheers,
Justin (Jia He)


> 
> Cheers,
> 
> --
> Julien Grall
_______________________________________________
Minios-devel mailing list
Minios-devel@xxxxxxxxxxxxxxxxxxxx
https://lists.xenproject.org/mailman/listinfo/minios-devel