Re: [PATCH v3 1/2] xen/arm: Defer request_irq on secondary CPUs after local_irq_enable

[Julien Grall <julien@xxxxxxx>]

On 15/05/2022 11:58, Julien Grall wrote:
> On 07/05/2022 03:54, Henry Wang wrote:
> > With the enhanced ASSERT_ALLOC_CONTEXT, calling request_irq before
> > local_irq_enable on secondary cores will lead to
> >
> > (XEN) Xen call trace:
> > (XEN) [<000000000021d86c>] alloc_xenheap_pages+0x74/0x194 (PC)
> > (XEN) [<000000000021d864>] alloc_xenheap_pages+0x6c/0x194 (LR)
> > (XEN) [<0000000000229e90>] xmalloc_tlsf.c#xmalloc_pool_get+0x1c/0x28
> > (XEN) [<000000000022a270>] xmem_pool_alloc+0x21c/0x448
> > (XEN) [<000000000022a8dc>] _xmalloc+0x8c/0x290
> > (XEN) [<000000000026b57c>] request_irq+0x40/0xb8
> > (XEN) [<0000000000272780>] init_timer_interrupt+0x74/0xcc
> > (XEN) [<000000000027212c>] start_secondary+0x1b4/0x238
> > (XEN) [<0000000084000200>] 0000000084000200
> > (XEN)
> > (XEN)
> > (XEN) ****************************************
> > (XEN) Panic on CPU 4:
> > (XEN) Assertion '!in_irq() && (local_irq_is_enabled() ||
> > num_online_cpus() <= 1)' failed at common/page_alloc.c:2212
> > (XEN) ****************************************
> >
> > on systems without a big enough pool for xmalloc() to cater the
> > requested size.
> >
> > Moving the call of request_irq() past local_irq_enable() on
> > secondary cores will make sure the assertion condition in
> > alloc_xenheap_pages(), i.e. !in_irq && local_irq_enabled() is
> > satisfied. It is also safe because the timer and GIC maintenance
> > interrupt will not be used until the CPU is fully online.
> >
> > Reported-by: Wei Chen <Wei.Chen@xxxxxxx>
> > Suggested-by: Julien Grall <jgrall@xxxxxxxxxx>
> > Signed-off-by: Henry Wang <Henry.Wang@xxxxxxx>
> Reviewed-by: Julien Grall <jgrall@xxxxxxxxxx>
I have committed this patch. The second patch will go in once 
"page_alloc: assert IRQs are enabled in heap alloc/free" has been 
re-committed.
Cheers,

--
Julien Grall