[PATCH 1/9] KVM: arm64: vgic-v3: Fix some error codes when setting RDIST base

[Eric Auger]

KVM_DEV_ARM_VGIC_GRP_ADDR group doc says we should return
-EEXIST in case the base address of the redist is already set.
We currently return -EINVAL.

However we need to return -EINVAL in case a legacy REDIST address
is attempted to be set while REDIST_REGIONS were set. This case
is discriminated by looking at the count field.

Signed-off-by: Eric Auger <eric.auger@xxxxxxxxxx>
---
 arch/arm64/kvm/vgic/vgic-mmio-v3.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/kvm/vgic/vgic-mmio-v3.c b/arch/arm64/kvm/vgic/vgic-mmio-v3.c
index 15a6c98ee92f..8e8a862def76 100644
--- a/arch/arm64/kvm/vgic/vgic-mmio-v3.c
+++ b/arch/arm64/kvm/vgic/vgic-mmio-v3.c
@@ -792,8 +792,13 @@ static int vgic_v3_insert_redist_region(struct kvm *kvm, uint32_t index,
 	int ret;
 
 	/* single rdist region already set ?*/
-	if (!count && !list_empty(rd_regions))
-		return -EINVAL;
+	if (!count && !list_empty(rd_regions)) {
+		rdreg = list_last_entry(rd_regions,
+				       struct vgic_redist_region, list);
+		if (rdreg->count)
+			return -EINVAL; /* Mixing REDIST and REDIST_REGION API */
+		return -EEXIST;
+	}
 
 	/* cross the end of memory ? */
 	if (base + size < base)
-- 
2.21.3