[PATCH][tip] x86/paravirt: Make the virt_spin_lock_key setup after jump_label_init()

From: Dou Liyang
Date: Fri Oct 27 2017 - 12:02:23 EST


Commit:

9043442b43b1 ("locking/paravirt: Use new static key for controlling
call of virt_spin_lock()")

set the static virt_spin_lock_key to a value before jump_label_init()
has been called, which will result in a WARN().

Move the native_pv_lock_init() into xx_smp_prepare_cpus(). Make the
setup later to avoid the WARN().

Reported-by: Juergen Gross <jgross@xxxxxxxx>
Suggested-by: Juergen Gross <jgross@xxxxxxxx>
Signed-off-by: Dou Liyang <douly.fnst@xxxxxxxxxxxxxx>
---
arch/x86/kernel/smpboot.c | 3 ++-
arch/x86/xen/smp_pv.c | 2 ++
arch/x86/xen/spinlock.c | 6 ++++--
3 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index aed1460..6b1335a 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -1323,6 +1323,8 @@ void __init native_smp_prepare_cpus(unsigned int max_cpus)
pr_info("CPU0: ");
print_cpu_info(&cpu_data(0));

+ native_pv_lock_init();
+
uv_system_init();

set_mtrr_aps_delayed_init();
@@ -1350,7 +1352,6 @@ void __init native_smp_prepare_boot_cpu(void)
/* already set me in cpu_online_mask in boot_cpu_init() */
cpumask_set_cpu(me, cpu_callout_mask);
cpu_set_state_online(me);
- native_pv_lock_init();
}

void __init native_smp_cpus_done(unsigned int max_cpus)
diff --git a/arch/x86/xen/smp_pv.c b/arch/x86/xen/smp_pv.c
index 5147140..570b2bc 100644
--- a/arch/x86/xen/smp_pv.c
+++ b/arch/x86/xen/smp_pv.c
@@ -236,6 +236,8 @@ static void __init xen_pv_smp_prepare_cpus(unsigned int max_cpus)
xen_raw_printk(m);
panic(m);
}
+ native_pv_lock_init();
+
xen_init_lock_cpu(0);

smp_store_boot_cpu_info();
diff --git a/arch/x86/xen/spinlock.c b/arch/x86/xen/spinlock.c
index e8ab80a..1e1462d 100644
--- a/arch/x86/xen/spinlock.c
+++ b/arch/x86/xen/spinlock.c
@@ -81,8 +81,11 @@ void xen_init_lock_cpu(int cpu)
int irq;
char *name;

- if (!xen_pvspin)
+ if (!xen_pvspin) {
+ if (cpu == 0)
+ static_branch_disable(&virt_spin_lock_key);
return;
+ }

WARN(per_cpu(lock_kicker_irq, cpu) >= 0, "spinlock on CPU%d exists on IRQ%d!\n",
cpu, per_cpu(lock_kicker_irq, cpu));
@@ -130,7 +133,6 @@ void __init xen_init_spinlocks(void)

if (!xen_pvspin) {
printk(KERN_DEBUG "xen: PV spinlocks disabled\n");
- static_branch_disable(&virt_spin_lock_key);
return;
}
printk(KERN_DEBUG "xen: PV spinlocks enabled\n");
--
2.5.5