diff --git a/metropolis/test/ktest/ktest.bzl b/metropolis/test/ktest/ktest.bzl
index 62cbd3a..f0f0eba 100644
--- a/metropolis/test/ktest/ktest.bzl
+++ b/metropolis/test/ktest/ktest.bzl
@@ -26,12 +26,12 @@
     z.update(y)
     return z
 
-def ktest(tester, cmdline = "", files = {}, files_cc = {}):
+def ktest(tester, cmdline = "", files = {}, fsspecs = [], files_cc = {}):
     node_initramfs(
         name = "test_initramfs",
         fsspecs = [
             "//metropolis/node/build:earlydev.fsspec",
-        ],
+        ] + fsspecs,
         files = _dict_union({
             "//metropolis/test/ktest/init": "/init",
             tester: "/tester",
diff --git a/metropolis/test/launch/launch.go b/metropolis/test/launch/launch.go
index 9760f54..cd51549 100644
--- a/metropolis/test/launch/launch.go
+++ b/metropolis/test/launch/launch.go
@@ -181,7 +181,7 @@
 	// Generate options for all the file descriptors we'll be passing as virtio "serial
 	// ports"
 	var extraArgs []string
-	for idx, _ := range opts.ExtraChardevs {
+	for idx := range opts.ExtraChardevs {
 		idxStr := strconv.Itoa(idx)
 		id := "extra" + idxStr
 		// That this works is pretty much a hack, but upstream QEMU doesn't have a
@@ -206,7 +206,7 @@
 			"-chardev", chardevConf.ToOption("pipe"), "-device", deviceConf.ToOption("virtserialport"))
 	}
 
-	for idx, _ := range opts.ExtraNetworkInterfaces {
+	for idx := range opts.ExtraNetworkInterfaces {
 		id := fmt.Sprintf("net%v", idx)
 		netdevConf := QemuValue{
 			"id": {id},
@@ -226,8 +226,10 @@
 	// kernel, initramfs and command line are mapped into VM memory at boot time and
 	// not loaded from any sort of disk. Booting and shutting off one of these VMs
 	// takes <100ms.
-	baseArgs := []string{"-nodefaults", "-no-user-config", "-nographic", "-no-reboot",
+	baseArgs := []string{
+		"-nodefaults", "-no-user-config", "-nographic", "-no-reboot",
 		"-accel", "kvm", "-cpu", "host",
+		"-m", "1G",
 		// Needed until QEMU updates their bundled qboot version (needs
 		// https://github.com/bonzini/qboot/pull/28)
 		"-bios", "external/com_github_bonzini_qboot/bios.bin",