xen/spinlock: Disable IRQ spinlock (PV) allocation on PVHVM

See git commit f10cd522c5fbfec9ae3cc01967868c9c2401ed23
(xen: disable PV spinlocks on HVM) for details.

But we did not disable it everywhere - which means that when
we boot as PVHVM we end up allocating per-CPU irq line for
spinlock. This fixes that.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

1 files changed, 21 insertions, 0 deletions

diff --git a/arch/x86/xen/spinlock.c b/arch/x86/xen/spinlock.c
index 47ae032f8d97..8b54603ce816 100644
--- a/arch/x86/xen/spinlock.c
+++ b/arch/x86/xen/spinlock.c
@@ -367,6 +367,13 @@ void __cpuinit xen_init_lock_cpu(int cpu)
         WARN(per_cpu(lock_kicker_irq, cpu) > 0, "spinlock on CPU%d exists on IRQ%d!\n",
              cpu, per_cpu(lock_kicker_irq, cpu));
 
+        /*
+         * See git commit f10cd522c5fbfec9ae3cc01967868c9c2401ed23
+         * (xen: disable PV spinlocks on HVM)
+         */
+        if (xen_hvm_domain())
+                return;
+
         name = kasprintf(GFP_KERNEL, "spinlock%d", cpu);
         irq = bind_ipi_to_irqhandler(XEN_SPIN_UNLOCK_VECTOR,
                                      cpu,
@@ -385,12 +392,26 @@ void __cpuinit xen_init_lock_cpu(int cpu)
 
 void xen_uninit_lock_cpu(int cpu)
 {
+        /*
+         * See git commit f10cd522c5fbfec9ae3cc01967868c9c2401ed23
+         * (xen: disable PV spinlocks on HVM)
+         */
+        if (xen_hvm_domain())
+                return;
+
         unbind_from_irqhandler(per_cpu(lock_kicker_irq, cpu), NULL);
         per_cpu(lock_kicker_irq, cpu) = -1;
 }
 
 void __init xen_init_spinlocks(void)
 {
+        /*
+         * See git commit f10cd522c5fbfec9ae3cc01967868c9c2401ed23
+         * (xen: disable PV spinlocks on HVM)
+         */
+        if (xen_hvm_domain())
+                return;
+
         BUILD_BUG_ON(sizeof(struct xen_spinlock) > sizeof(arch_spinlock_t));
 
         pv_lock_ops.spin_is_locked = xen_spin_is_locked;