diff --git a/.cirrus.yml b/.cirrus.yml
index bf76a6b23..c6d238726 100644
--- a/.cirrus.yml
+++ b/.cirrus.yml
@@ -1,7 +1,8 @@
 ---
-# We use Cirrus for Vagrant tests and native CentOS 7 and 8, because macOS
-# instances of GHA are too slow and flaky, and Linux instances of GHA do not
-# support KVM.
+# We use Cirrus for CentOS (native) and Fedora (in Vagrant), because neither
+# CentOS nor Fedora is available on GHA natively, so the only option is VM.
+# In GHA, nested virtualization is only supported on macOS instances, which
+# are slow and flaky.
 
 # NOTE Cirrus execution environments lack a terminal, needed for
 # some integration tests. So we use `ssh -tt` command to fake a terminal.
@@ -24,9 +25,9 @@ task:
     platform: linux
     nested_virtualization: true
     # CPU limit: `16 / NTASK`: see https://cirrus-ci.org/faq/#are-there-any-limits
-    cpu: 8
+    cpu: 4
     # Memory limit: `4GB * NCPU`
-    memory: 32G
+    memory: 16G
 
   host_info_script: |
     uname -a
@@ -47,8 +48,8 @@ task:
     apt-get install -y --no-install-recommends libxslt-dev libxml2-dev libvirt-dev ruby-bundler ruby-dev zlib1g-dev
     vagrant plugin install vagrant-libvirt
   vagrant_cache:
-    fingerprint_script: uname -s ; cat Vagrantfile.$DISTRO
-    folder: /root/.vagrant.d
+    fingerprint_script: cat Vagrantfile.$DISTRO
+    folder: /root/.vagrant.d/boxes
   vagrant_up_script: |
     ln -sf Vagrantfile.$DISTRO Vagrantfile
     # Retry if it fails (download.fedoraproject.org returns 404 sometimes)