2022-02-22 09:29:27

by Wanpeng Li

[permalink] [raw]
Subject: [PATCH] x86/kvm: Don't waste memory if kvmclock is disabled

From: Wanpeng Li <[email protected]>

Even if "no-kvmclock" is passed in cmdline parameter, the guest kernel
still allocates hvclock_mem which is scaled by the number of vCPUs,
let's check kvmclock enable in advance to avoid this memory waste.

Signed-off-by: Wanpeng Li <[email protected]>
---
arch/x86/kernel/kvmclock.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/arch/x86/kernel/kvmclock.c b/arch/x86/kernel/kvmclock.c
index a35cbf9107af..44ed677d401f 100644
--- a/arch/x86/kernel/kvmclock.c
+++ b/arch/x86/kernel/kvmclock.c
@@ -239,6 +239,9 @@ static void __init kvmclock_init_mem(void)

static int __init kvm_setup_vsyscall_timeinfo(void)
{
+ if (!kvmclock)
+ return 0;
+
kvmclock_init_mem();

#ifdef CONFIG_X86_64
--
2.25.1