Re: [PATCH for-4.22 v2 3/4] xen/irq: handle IRQ being disabled while executing its handler

["Roger Pau Monné" <roger.pau@citrix.com>]

On Mon, Jun 29, 2026 at 12:31:56PM +0200, Jan Beulich wrote:
> On 29.06.2026 11:45, Roger Pau Monne wrote:
> > It's possible for IRQ_DISABLED to be set while running the handler
> > execution loop in do_IRQ().  Such disabling can be done by the handler
> > itself, or from a remote CPU.
> 
> I don't think the handler itself can legitimately call any of the functions
> setting IRQ_DISABLED.

Hm, yes, we still have no interrupt handlers that set IRQ_DISABLED,
but we will gain one in the next patch, where ns16550_interrupt() will
call disable_irq() that does set IRQ_DISABLED.

> > Check for IRQ_DISABLED not being set in the loop condition, as to not
> > execute the handler if the IRQ has been disabled.
> > 
> > Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
> 
> Preferably with the description adjusted (or it being pointed out what I may
> be overlooking):
> Reviewed-by: Jan Beulich <jbeulich@suse.com>

I'm happy to clarify the commit message to note that while we have no
instances ATM, but that future changes might introduce some.

Thanks, Roger.