[pve-devel] [PATCH qemu-server v4 1/9] remove outdated /dev/random entropy-starvation warnings

[Filip Schauer]

Remove mentions about entropy-starvation, when using /dev/random as the
entropy source, from the descriptions of the rng parameters. This
concern no longer applies since the removal of the blocking entropy pool
in kernel version 5.6. [1] [2]

[1] https://git.kernel.org/torvalds/c/acd77500aa8a337baa6d853568c4b55aca48e20f
[2] https://lwn.net/Articles/808575/

Signed-off-by: Filip Schauer <f.schauer at proxmox.com>
---
 PVE/QemuServer.pm | 13 +++++--------
 1 file changed, 5 insertions(+), 8 deletions(-)

diff --git a/PVE/QemuServer.pm b/PVE/QemuServer.pm
index 808c0e1c..a1237c05 100644
--- a/PVE/QemuServer.pm
+++ b/PVE/QemuServer.pm
@@ -253,18 +253,15 @@ my $rng_fmt = {
 	type => 'string',
 	enum => ['/dev/urandom', '/dev/random', '/dev/hwrng'],
 	default_key => 1,
-	description => "The file on the host to gather entropy from. In most cases '/dev/urandom'"
-	    ." should be preferred over '/dev/random' to avoid entropy-starvation issues on the"
-	    ." host. Using urandom does *not* decrease security in any meaningful way, as it's"
-	    ." still seeded from real entropy, and the bytes provided will most likely be mixed"
-	    ." with real entropy on the guest as well. '/dev/hwrng' can be used to pass through"
-	    ." a hardware RNG from the host.",
+	description => "The file on the host to gather entropy from. Using urandom does *not*"
+	    ." decrease security in any meaningful way, as it's still seeded from real entropy, and"
+	    ." the bytes provided will most likely be mixed with real entropy on the guest as well."
+	    ."'/dev/hwrng' can be used to pass through a hardware RNG from the host.",
     },
     max_bytes => {
 	type => 'integer',
 	description => "Maximum bytes of entropy allowed to get injected into the guest every"
-	    ." 'period' milliseconds. Prefer a lower value when using '/dev/random' as source. Use"
-	    ." `0` to disable limiting (potentially dangerous!).",
+	    ." 'period' milliseconds. Use `0` to disable limiting (potentially dangerous!).",
 	optional => 1,
 
 	# default is 1 KiB/s, provides enough entropy to the guest to avoid boot-starvation issues
-- 
2.39.5