KVM: convert ioapic lock to spinlock

kvm_set_irq is used from non sleepable contexes, so convert ioapic from
mutex to spinlock.

KVM-Stable-Tag.
Tested-by: Ralf Bonenkamp <ralf.bonenkamp@swyx.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

2 files changed, 16 insertions, 16 deletions

diff --git a/virt/kvm/ioapic.c b/virt/kvm/ioapic.c
index 03a5eb22da2b..7c79c1d76d0c 100644
--- a/virt/kvm/ioapic.c
+++ b/virt/kvm/ioapic.c
@@ -197,7 +197,7 @@ int kvm_ioapic_set_irq(struct kvm_ioapic *ioapic, int irq, int level)
         union kvm_ioapic_redirect_entry entry;
         int ret = 1;
 
-        mutex_lock(&ioapic->lock);
+        spin_lock(&ioapic->lock);
         if (irq >= 0 && irq < IOAPIC_NUM_PINS) {
                 entry = ioapic->redirtbl[irq];
                 level ^= entry.fields.polarity;
@@ -214,7 +214,7 @@ int kvm_ioapic_set_irq(struct kvm_ioapic *ioapic, int irq, int level)
                 }
                 trace_kvm_ioapic_set_irq(entry.bits, irq, ret == 0);
         }
-        mutex_unlock(&ioapic->lock);
+        spin_unlock(&ioapic->lock);
 
         return ret;
 }
@@ -238,9 +238,9 @@ static void __kvm_ioapic_update_eoi(struct kvm_ioapic *ioapic, int vector,
                  * is dropped it will be put into irr and will be delivered
                  * after ack notifier returns.
                  */
-                mutex_unlock(&ioapic->lock);
+                spin_unlock(&ioapic->lock);
                 kvm_notify_acked_irq(ioapic->kvm, KVM_IRQCHIP_IOAPIC, i);
-                mutex_lock(&ioapic->lock);
+                spin_lock(&ioapic->lock);
 
                 if (trigger_mode != IOAPIC_LEVEL_TRIG)
                         continue;
@@ -259,9 +259,9 @@ void kvm_ioapic_update_eoi(struct kvm *kvm, int vector, int trigger_mode)
         smp_rmb();
         if (!test_bit(vector, ioapic->handled_vectors))
                 return;
-        mutex_lock(&ioapic->lock);
+        spin_lock(&ioapic->lock);
         __kvm_ioapic_update_eoi(ioapic, vector, trigger_mode);
-        mutex_unlock(&ioapic->lock);
+        spin_unlock(&ioapic->lock);
 }
 
 static inline struct kvm_ioapic *to_ioapic(struct kvm_io_device *dev)
@@ -287,7 +287,7 @@ static int ioapic_mmio_read(struct kvm_io_device *this, gpa_t addr, int len,
         ASSERT(!(addr & 0xf));  /* check alignment */
 
         addr &= 0xff;
-        mutex_lock(&ioapic->lock);
+        spin_lock(&ioapic->lock);
         switch (addr) {
         case IOAPIC_REG_SELECT:
                 result = ioapic->ioregsel;
@@ -301,7 +301,7 @@ static int ioapic_mmio_read(struct kvm_io_device *this, gpa_t addr, int len,
                 result = 0;
                 break;
         }
-        mutex_unlock(&ioapic->lock);
+        spin_unlock(&ioapic->lock);
 
         switch (len) {
         case 8:
@@ -338,7 +338,7 @@ static int ioapic_mmio_write(struct kvm_io_device *this, gpa_t addr, int len,
         }
 
         addr &= 0xff;
-        mutex_lock(&ioapic->lock);
+        spin_lock(&ioapic->lock);
         switch (addr) {
         case IOAPIC_REG_SELECT:
                 ioapic->ioregsel = data;
@@ -356,7 +356,7 @@ static int ioapic_mmio_write(struct kvm_io_device *this, gpa_t addr, int len,
         default:
                 break;
         }
-        mutex_unlock(&ioapic->lock);
+        spin_unlock(&ioapic->lock);
         return 0;
 }
 
@@ -386,7 +386,7 @@ int kvm_ioapic_init(struct kvm *kvm)
         ioapic = kzalloc(sizeof(struct kvm_ioapic), GFP_KERNEL);
         if (!ioapic)
                 return -ENOMEM;
-        mutex_init(&ioapic->lock);
+        spin_lock_init(&ioapic->lock);
         kvm->arch.vioapic = ioapic;
         kvm_ioapic_reset(ioapic);
         kvm_iodevice_init(&ioapic->dev, &ioapic_mmio_ops);
@@ -419,9 +419,9 @@ int kvm_get_ioapic(struct kvm *kvm, struct kvm_ioapic_state *state)
         if (!ioapic)
                 return -EINVAL;
 
-        mutex_lock(&ioapic->lock);
+        spin_lock(&ioapic->lock);
         memcpy(state, ioapic, sizeof(struct kvm_ioapic_state));
-        mutex_unlock(&ioapic->lock);
+        spin_unlock(&ioapic->lock);
         return 0;
 }
 
@@ -431,9 +431,9 @@ int kvm_set_ioapic(struct kvm *kvm, struct kvm_ioapic_state *state)
         if (!ioapic)
                 return -EINVAL;
 
-        mutex_lock(&ioapic->lock);
+        spin_lock(&ioapic->lock);
         memcpy(ioapic, state, sizeof(struct kvm_ioapic_state));
         update_handled_vectors(ioapic);
-        mutex_unlock(&ioapic->lock);
+        spin_unlock(&ioapic->lock);
         return 0;
 }
diff --git a/virt/kvm/ioapic.h b/virt/kvm/ioapic.h
index 8a751b78a430..0b190c34ccc3 100644
--- a/virt/kvm/ioapic.h
+++ b/virt/kvm/ioapic.h
@@ -45,7 +45,7 @@ struct kvm_ioapic {
         struct kvm_io_device dev;
         struct kvm *kvm;
         void (*ack_notifier)(void *opaque, int irq);
-        struct mutex lock;
+        spinlock_t lock;
         DECLARE_BITMAP(handled_vectors, 256);
 };