[Xen-devel] [PATCH] xen/arm: vgic: Make sure the number of SPIs is a multiple of 32

[Julien Grall <julien.grall@xxxxxxx>]

The vGIC relies on having a pending_irq available for every IRQs
described in the ranks. As each rank describes 32 interrupts, we need to
make sure the number of SPIs is a multiple of 32.

Reported-by: Jarvis Roach <Jarvis.Roach@xxxxxxxxxxxxxxx>
Signed-off-by: Julien Grall <julien.grall@xxxxxxx>

---
    Jarvis, I don't have Jeff's e-mail address so I put you as the
    report. Let me know if you want to change that.

    This should be backported up to Xen 4.8.
---
 xen/arch/arm/vgic.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/xen/arch/arm/vgic.c b/xen/arch/arm/vgic.c
index 9921769b15..34269bcf27 100644
--- a/xen/arch/arm/vgic.c
+++ b/xen/arch/arm/vgic.c
@@ -123,6 +123,13 @@ int domain_vgic_init(struct domain *d, unsigned int 
nr_spis)
 
     d->arch.vgic.ctlr = 0;
 
+    /*
+     * The vGIC relies on having a pending_irq available for every IRQ
+     * described in the ranks. As each rank describes 32 interrupts, we
+     * need to make sure the number of SPIs is a multiple of 32.
+     */
+    nr_spis = ROUNDUP(nr_spis, 32);
+
     /* Limit the number of virtual SPIs supported to (1020 - 32) = 988  */
     if ( nr_spis > (1020 - NR_LOCAL_IRQS) )
         return -EINVAL;
-- 
2.11.0


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