[PATCH 3/4] ARM: KVM: Bugfix: vgic_bytemap_get_reg per cpu regs

Marc Zyngier
2013-08-29T10:08:34Z

From: Christoffer Dall <christoffer.dall@linaro.org>

For bytemaps each IRQ field is 1 byte wide, so we pack 4 irq fields in
one word and since there are 32 private (per cpu) irqs, we have 8
private u32 fields on the vgic_bytemap struct. We shift the offset from
the base of the register group right by 2, giving us the word index
instead of the field index. But then there are 8 private words, not 4,
which is also why we subtract 8 words from the offset of the shared
words.

Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
virt/kvm/arm/vgic.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/virt/kvm/arm/vgic.c b/virt/kvm/arm/vgic.c
index 902789f..685fc72 100644
--- a/virt/kvm/arm/vgic.c
+++ b/virt/kvm/arm/vgic.c
@@ -149,7 +149,7 @@ static u32 *vgic_bytemap_get_reg(struct vgic_bytemap *x, int cpuid, u32 offset)
{
offset >>= 2;
BUG_ON(offset > (VGIC_NR_IRQS / 4));
- if (offset < 4)
+ if (offset < 8)
return x->percpu[cpuid] + offset;
else
return x->shared + offset - 8;
--
1.8.2.3