KVM: introduce irq_lock, use it to protect ioapic

Introduce irq_lock, and use to protect ioapic data structures.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

2 files changed, 6 insertions, 0 deletions

diff --git a/virt/kvm/ioapic.c b/virt/kvm/ioapic.c
index 469b9faae665..2a5667173995 100644
--- a/virt/kvm/ioapic.c
+++ b/virt/kvm/ioapic.c
@@ -243,6 +243,7 @@ static void ioapic_mmio_read(struct kvm_io_device *this, gpa_t addr, int len,
         ioapic_debug("addr %lx\n", (unsigned long)addr);
         ASSERT(!(addr & 0xf));  /* check alignment */
 
+        mutex_lock(&ioapic->kvm->irq_lock);
         addr &= 0xff;
         switch (addr) {
         case IOAPIC_REG_SELECT:
@@ -269,6 +270,7 @@ static void ioapic_mmio_read(struct kvm_io_device *this, gpa_t addr, int len,
         default:
                 printk(KERN_WARNING "ioapic: wrong length %d\n", len);
         }
+        mutex_unlock(&ioapic->kvm->irq_lock);
 }
 
 static void ioapic_mmio_write(struct kvm_io_device *this, gpa_t addr, int len,
@@ -280,6 +282,8 @@ static void ioapic_mmio_write(struct kvm_io_device *this, gpa_t addr, int len,
         ioapic_debug("ioapic_mmio_write addr=%p len=%d val=%p\n",
                      (void*)addr, len, val);
         ASSERT(!(addr & 0xf));  /* check alignment */
+
+        mutex_lock(&ioapic->kvm->irq_lock);
         if (len == 4 || len == 8)
                 data = *(u32 *) val;
         else {
@@ -305,6 +309,7 @@ static void ioapic_mmio_write(struct kvm_io_device *this, gpa_t addr, int len,
         default:
                 break;
         }
+        mutex_unlock(&ioapic->kvm->irq_lock);
 }
 
 void kvm_ioapic_reset(struct kvm_ioapic *ioapic)
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index d1f9c87daa87..d47e660fb709 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -982,6 +982,7 @@ static struct kvm *kvm_create_vm(void)
         kvm_io_bus_init(&kvm->pio_bus);
         kvm_irqfd_init(kvm);
         mutex_init(&kvm->lock);
+        mutex_init(&kvm->irq_lock);
         kvm_io_bus_init(&kvm->mmio_bus);
         init_rwsem(&kvm->slots_lock);
         atomic_set(&kvm->users_count, 1);