From 0a5d3c0b5bfee68102de6345a3cd5580fbd5da02 Mon Sep 17 00:00:00 2001
From: Lennart Poettering <lennart@poettering.net>
Date: Tue, 18 Apr 2023 10:48:54 +0200
Subject: [PATCH] kmod-setup: bypass heavy virtio-rng check if we are not
 running in a VM anyway

detect_vm() is cheap, because cached, let's hence do that early before
we get out the big guns and sweep through sysfs.
---
 src/core/kmod-setup.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/core/kmod-setup.c b/src/core/kmod-setup.c
index 949b1a5854a..adf817800f4 100644
--- a/src/core/kmod-setup.c
+++ b/src/core/kmod-setup.c
@@ -67,6 +67,10 @@ static int has_virtio_rng_recurse_dir_cb(
 static bool has_virtio_rng(void) {
         int r;
 
+        /* Directory traversal might be slow, hence let's do a cheap check first if it's even worth it */
+        if (detect_vm() == VIRTUALIZATION_NONE)
+                return false;
+
         r = recurse_dir_at(
                         AT_FDCWD,
                         "/sys/devices/pci0000:00",