From ef935c25fd648a17c27af5d1738b1884f78c5b75 Mon Sep 17 00:00:00 2001 From: Erwan Velu Date: Thu, 27 Feb 2020 19:00:46 +0100 Subject: [PATCH] kvm: x86: Limit the number of "kvm: disabled by bios" messages In older version of systemd(219), at boot time, udevadm is called with : /usr/bin/udevadm trigger --type=devices --action=add" This program generates an echo "add" in /sys/devices/system/cpu/cpu/uevent, leading to the "kvm: disabled by bios" message in case of your Bios disabled the virtualization extensions. On a modern system running up to 256 CPU threads, this pollutes the Kernel logs. This patch offers to ratelimit this message to avoid any userspace program triggering this uevent printing this message too often. This patch is only a workaround but greatly reduce the pollution without breaking the current behavior of printing a message if some try to instantiate KVM on a system that doesn't support it. Note that recent versions of systemd (>239) do not have trigger this behavior. This patch will be useful at least for some using older systemd with recent Kernels. Signed-off-by: Erwan Velu Signed-off-by: Paolo Bonzini --- arch/x86/kvm/x86.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index bcb6b67..5de2006 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -7308,12 +7308,12 @@ int kvm_arch_init(void *opaque) } if (!ops->cpu_has_kvm_support()) { - printk(KERN_ERR "kvm: no hardware support\n"); + pr_err_ratelimited("kvm: no hardware support\n"); r = -EOPNOTSUPP; goto out; } if (ops->disabled_by_bios()) { - printk(KERN_ERR "kvm: disabled by bios\n"); + pr_err_ratelimited("kvm: disabled by bios\n"); r = -EOPNOTSUPP; goto out; } -- 2.7.4