tests: Use hugepages for test_vfio

Using hugepages with VFIO and virtiofs can improve the performance of
the test_vfio test.

Signed-off-by: Rob Bradford <robert.bradford@intel.com>
(cherry picked from commit 5c9828a34c)

scripts/run_integration_tests.sh

@@ -173,6 +173,10 @@ sudo bash -c "echo 1 > /sys/kernel/mm/ksm/run"
 time cargo test --no-run --features "integration_tests" -- --nocapture
 ls target/debug/deps/cloud_hypervisor-* | xargs -n 1 sudo setcap cap_net_admin+ep
 
+# test_vfio relies on hugepages
+echo 4096 | sudo tee /proc/sys/vm/nr_hugepages
+sudo chmod a+rwX /dev/hugepages
+
 sudo adduser $USER kvm
 newgrp kvm << EOF
 export RUST_BACKTRACE=1