From: DaanDeMeyer <daan.j.demeyer@gmail.com>
Date: Thu, 3 Jul 2025 08:37:25 +0000 (+0200)
Subject: vmspawn: Disable hpet for vmspawn x86 virtual machines
X-Git-Tag: v258-rc1~117
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=8ba6c2b7f51ca7cdb0031e10dca8ab6bd06071a1;p=thirdparty%2Fsystemd.git

vmspawn: Disable hpet for vmspawn x86 virtual machines

hpet is an emulated clocksource that is generally discouraged in favor
of kvm-clock or tsc for virtual machines. While vmspawn's virtual machines
already use kvm-clock, leaving hpet enabled causes qemu on the host to
consume a non-trivial amount of cpu, so let's disable the hpet feature since
we're not making use of it anyway.
---

diff --git a/src/vmspawn/vmspawn-util.h b/src/vmspawn/vmspawn-util.h
index a8a69a9e50f..f851fd48e03 100644
--- a/src/vmspawn/vmspawn-util.h
+++ b/src/vmspawn/vmspawn-util.h
@@ -27,6 +27,12 @@
 #  define ARCHITECTURE_SUPPORTS_SMM 0
 #endif
 
+#if defined(__x86_64__) || defined(__i386__)
+#  define ARCHITECTURE_SUPPORTS_HPET 1
+#else
+#  define ARCHITECTURE_SUPPORTS_HPET 0
+#endif
+
 #if defined(__x86_64__) || defined(__i386__)
 #  define QEMU_MACHINE_TYPE "q35"
 #elif defined(__arm__) || defined(__aarch64__) || defined(__riscv) || defined(__loongarch64)
diff --git a/src/vmspawn/vmspawn.c b/src/vmspawn/vmspawn.c
index a3dd1432b28..2771b263498 100644
--- a/src/vmspawn/vmspawn.c
+++ b/src/vmspawn/vmspawn.c
@@ -1578,10 +1578,11 @@ static int run_virtual_machine(int kvm_device_fd, int vhost_device_fd) {
                             "falling back to OVMF firmware blobs without Secure Boot support.");
 
         shm = arg_directory || arg_runtime_mounts.n_mounts != 0 ? ",memory-backend=mem" : "";
+        const char *hpet = ARCHITECTURE_SUPPORTS_HPET ? ",hpet=off" : "";
         if (ARCHITECTURE_SUPPORTS_SMM)
-                machine = strjoin("type=" QEMU_MACHINE_TYPE ",smm=", on_off(ovmf_config->supports_sb), shm);
+                machine = strjoin("type=" QEMU_MACHINE_TYPE ",smm=", on_off(ovmf_config->supports_sb), shm, hpet);
         else
-                machine = strjoin("type=" QEMU_MACHINE_TYPE, shm);
+                machine = strjoin("type=" QEMU_MACHINE_TYPE, shm, hpet);
         if (!machine)
                 return log_oom();