Benchmark nested virtualization memory performance

tests/integration_tests/performance/README_sysbench_pause_resume.md

@@ -0,0 +1,35 @@
+# Snapshot/Restore Memory Benchmark
+
+dd 1 GiB to `/dev/shm` after full snapshot/restore. 2 vCPUs, 2048 MiB RAM.
+
+Scenarios: `normal_no_uffd`, `normal_no_uffd_dirty_tracking`, `normal_uffd`, `hugepages_uffd`.
+
+## Prerequisites
+
+- Linux with `/dev/kvm` (bare-metal or nested virt)
+- Docker
+- AWS CLI v2
+
+```bash
+# Docker
+sudo apt-get update && sudo apt-get install -y docker.io
+sudo systemctl enable --now docker
+
+# AWS CLI v2
+curl -sL https://awscli.amazonaws.com/awscli-exe-linux-x86_64.zip -o /tmp/awscliv2.zip
+cd /tmp && unzip -qo awscliv2.zip && sudo ./aws/install
+rm -rf /tmp/aws /tmp/awscliv2.zip
+
+# Hugepages (needed for hugepages_uffd scenario, 1024 pages + buffer)
+echo 1200 | sudo tee /sys/kernel/mm/hugepages/hugepages-2048kB/nr_hugepages
+```
+
+## Run
+
+```bash
+sudo ./tools/devtool -y test --performance -- \
+    -m nonci -s \
+    integration_tests/performance/test_sysbench_pause_resume.py
+```
+
+`sudo` required for the userfaultfd handler. `-m nonci` selects the benchmark. `-s` shows output.