KVM: arm64: GICv3: mandate page-aligned GICV region

Just like GICv2 was fixed in 63afbe7a0ac1
(kvm: arm64: vgic: fix hyp panic with 64k pages on juno platform),
mandate the GICV region to be both aligned on a page boundary and
its size to be a multiple of page size.

This prevents a guest from being able to poke at regions where we
have no idea what is sitting there.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

1 files changed, 16 insertions, 0 deletions

diff --git a/virt/kvm/arm/vgic-v3.c b/virt/kvm/arm/vgic-v3.c
index f01d44685720..1c2c8eef0599 100644
--- a/virt/kvm/arm/vgic-v3.c
+++ b/virt/kvm/arm/vgic-v3.c
@@ -215,6 +215,22 @@ int vgic_v3_probe(struct device_node *vgic_node,
                 ret = -ENXIO;
                 goto out;
         }
+
+        if (!PAGE_ALIGNED(vcpu_res.start)) {
+                kvm_err("GICV physical address 0x%llx not page aligned\n",
+                        (unsigned long long)vcpu_res.start);
+                ret = -ENXIO;
+                goto out;
+        }
+
+        if (!PAGE_ALIGNED(resource_size(&vcpu_res))) {
+                kvm_err("GICV size 0x%llx not a multiple of page size 0x%lx\n",
+                        (unsigned long long)resource_size(&vcpu_res),
+                        PAGE_SIZE);
+                ret = -ENXIO;
+                goto out;
+        }
+
         vgic->vcpu_base = vcpu_res.start;
         vgic->vctrl_base = NULL;
         vgic->type = VGIC_V3;