xen/arm: vgic-v2: Correctly set GICD_TYPER.CPUNumber

The number of implemented CPU interfaces is one more than the value of
this field.

Also avoid hardcoding the shift and remove useless mask.

Signed-off-by: Julien Grall <julien.grall@linaro.org>
Acked-by: Ian Campbell <ian.campbell@citrix.com>

diff --git a/xen/arch/arm/vgic-v2.c b/xen/arch/arm/vgic-v2.c
index 3b87f540129cd8ca9446693a9d842e835e7fce05..0cf82efeba71d73a26751f6b3e3b394cf10c12c4 100644 (file)
--- a/xen/arch/arm/vgic-v2.c
+++ b/xen/arch/arm/vgic-v2.c
@@ -55,7 +55,7 @@ static int vgic_v2_distr_mmio_read(struct vcpu *v, mmio_info_t *info)
         if ( dabt.size != DABT_WORD ) goto bad_width;
         /* No secure world support for guests. */
         vgic_lock(v);
-        *r = ( (v->domain->max_vcpus << 5) & GICD_TYPE_CPUS )
+        *r = ( ((v->domain->max_vcpus - 1) << GICD_TYPE_CPUS_SHIFT) )
             |( ((v->domain->arch.vgic.nr_spis / 32)) & GICD_TYPE_LINES );
         vgic_unlock(v);
         return 1;