On Mon, May 13, 2019 at 10:42:44AM +0200, Cédric Le Goater wrote:
> Recent commits changed the behavior of ics_set_irq_type() to
> initialize correctly LSIs at the KVM level. ics_set_irq_type() is also
> called by the realize routine of the different devices of the machine
> when initial interrupts are claimed, before the ICSState device is
> reseted.
>
> In the case, the ICSIRQState priority is 0x0 and the call to
> ics_set_irq_type() results in configuring the target of the
> interrupt. On P9, when using the KVM XICS-on-XIVE device, the target
> is configured to be server 0, priority 0 and the event queue 0 is
> created automatically by KVM.
>
> With the dual interrupt mode creating the KVM device at reset, it
> leads to unexpected effects on the guest, mostly blocking IPIs. This
> is wrong, fix it by reseting the ICSIRQState structure when
> ics_set_irq_type() is called.
>
> Fixes: commit 6cead90c5c9c ("xics: Write source state to KVM at claim time")
> Signed-off-by: Greg Kurz <[email protected]>
> Signed-off-by: Cédric Le Goater <[email protected]>Reviewed-by: David Gibson <[email protected]> > --- > hw/intc/xics.c | 10 ++++++++-- > 1 file changed, 8 insertions(+), 2 deletions(-) > > diff --git a/hw/intc/xics.c b/hw/intc/xics.c > index af7dc709abab..79f5a8a91665 100644 > --- a/hw/intc/xics.c > +++ b/hw/intc/xics.c > @@ -610,6 +610,12 @@ static const TypeInfo ics_simple_info = { > .class_size = sizeof(ICSStateClass), > }; > > +static void ics_reset_irq(ICSIRQState *irq) > +{ > + irq->priority = 0xff; > + irq->saved_priority = 0xff; > +} > + > static void ics_base_reset(DeviceState *dev) > { > ICSState *ics = ICS_BASE(dev); > @@ -623,8 +629,7 @@ static void ics_base_reset(DeviceState *dev) > memset(ics->irqs, 0, sizeof(ICSIRQState) * ics->nr_irqs); > > for (i = 0; i < ics->nr_irqs; i++) { > - ics->irqs[i].priority = 0xff; > - ics->irqs[i].saved_priority = 0xff; > + ics_reset_irq(ics->irqs + i); > ics->irqs[i].flags = flags[i]; > } > } > @@ -760,6 +765,7 @@ void ics_set_irq_type(ICSState *ics, int srcno, bool lsi) > lsi ? XICS_FLAGS_IRQ_LSI : XICS_FLAGS_IRQ_MSI; > > if (kvm_irqchip_in_kernel()) { > + ics_reset_irq(ics->irqs + srcno); > ics_set_kvm_state_one(ics, srcno); > } > } -- David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson
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