On 1/15/2016 12:34 PM, Yuanhan Liu wrote:

Modern (v1.0) virtio pci device defines several pci capabilities.
Each cap has a configure structure corresponding to it, and the
cap.bar and cap.offset fields tell us where to find it.

[snip]

 
+static void *
+get_cfg_addr(struct rte_pci_device *dev, struct virtio_pci_cap *cap)
+{
+	uint8_t  bar    = cap->bar;
+	uint32_t length = cap->length;
+	uint32_t offset = cap->offset;
+	uint8_t *base;
+
+	if (bar > 5) {
+		PMD_INIT_LOG(ERR, "invalid bar: %u", bar);
+		return NULL;
+	}
+
+	if (offset + length > dev->mem_resource[bar].len) {

offset + length could overflow 32bit limit

+		PMD_INIT_LOG(ERR,
+			"invalid cap: overflows bar space: %u > %"PRIu64,
+			offset + length, dev->mem_resource[bar].len);
+		return NULL;
+	}
+
+	

[snip]