Re: [PATCH 5/7] xen/events: drop xen_allocate_irqs_dynamic()

From: Oleksandr Tyshchenko
Date: Tue Nov 14 2023 - 03:20:28 EST




On 16.10.23 09:28, Juergen Gross wrote:


Hello Juergen

> Instead of having a common function for allocating a single IRQ or a
> consecutive number of IRQs, split up the functionality into the callers
> of xen_allocate_irqs_dynamic().
>
> This allows to handle any allocation error in xen_irq_init() gracefully
> instead of panicing the system. Let xen_irq_init() return the irq_info
> pointer or NULL in case of an allocation error.
>
> Additionally set the IRQ into irq_info already at allocation time, as
> otherwise the IRQ would be '0' (which is a valid IRQ number) until
> being set.
>
> Signed-off-by: Juergen Gross <jgross@xxxxxxxx>
> ---
> drivers/xen/events/events_base.c | 74 +++++++++++++++++++-------------
> 1 file changed, 44 insertions(+), 30 deletions(-)
>

[snip]

> @@ -1725,6 +1738,7 @@ void rebind_evtchn_irq(evtchn_port_t evtchn, int irq)
> so there should be a proper type */
> BUG_ON(info->type == IRQT_UNBOUND);
>
> + info->irq = irq;


I failed to understand why this is added here. Doesn't irq remain the
same, and info->irq remains valid? Could you please clarify.

Other changes lgtm.


> (void)xen_irq_info_evtchn_setup(irq, evtchn, NULL);
>
> mutex_unlock(&irq_mapping_update_lock);