Re: Keystone Issue

[Julien Grall <julien@xxxxxxx>]

(+ Marc)

On 09/06/2020 18:03, Bertrand Marquis wrote:
> Hi
>
> > On 9 Jun 2020, at 16:47, Julien Grall <julien@xxxxxxx> wrote:
> >
> >
> >
> > On 09/06/2020 16:28, Bertrand Marquis wrote:
> > > Hi,
> > > > On 9 Jun 2020, at 15:33, CodeWiz2280 <codewiz2280@xxxxxxxxx> wrote:
> > > >
> > > > There does appear to be a secondary (CIC) controller that can forward
> > > > events to the GIC-400 and EDMA controllers for the keystone 2 family.
> > > > Admittedly, i'm not sure how it is being used with regards to the
> > > > peripherals.  I only see mention of the GIC-400 parent for the devices
> > > > in the device tree.  Maybe Bertrand has a better idea on whether any
> > > > peripherals go through the CIC first?  I see that gic_interrupt ()
> > > > fires once in Xen, which calls doIRQ to push out the virtual interrupt
> > > > to the dom0 kernel.  The dom0 kernel then handles the interrupt and
> > > > returns, but gic_interrupt() never fires again in Xen.
> > > I do not remember of any CIC but the behaviour definitely look like an 
> > > interrupt acknowledge problem.
> > > Could you try the following:
> > > --- a/xen/arch/arm/gic-v2.c
> > > +++ b/xen/arch/arm/gic-v2.c
> > > @@ -667,6 +667,9 @@ static void gicv2_guest_irq_end(struct irq_desc *desc)
> > >       /* Lower the priority of the IRQ */
> > >       gicv2_eoi_irq(desc);
> > >       /* Deactivation happens in maintenance interrupt / via GICV */
> > > +
> > > +    /* Test for Keystone2 */
> > > +    gicv2_dir_irq(desc);
> > >   }
> > > I think the problem I had was related to the vgic not deactivating properly the 
> > > interrupt.
> > Are you suggesting the guest EOI is not properly forwarded to the hardware when 
> > LR.HW is set? If so, this could possibly be workaround in Xen by raising a 
> > maintenance interrupt every time a guest EOI an interrupt.
> Agree the maintenance interrupt would definitely be the right solution
I would like to make sure we aren't missing anything in Xen first. From 
what you said, you have encountered this issue in the past with a 
different hypervisor. So it doesn't look like to be Xen related.
Was there any official statement from TI? If not, can we try to get some 
input from them first?
        
@Marc, I know you dropped 32-bit support in KVM recently :). Although, I 
was wondering if you heard about any potential issue with guest EOI not 
forwarded to the host. This is on TI Keystone (Cortex A-15).
Cheers,

--
Julien Grall