Merge tag 'kvm-4.15-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm

[linux-2.6-block.git] / arch / s390 / kvm / interrupt.c

diff --git a/arch/s390/kvm/interrupt.c b/arch/s390/kvm/interrupt.c
index 329b2843fee2161093f13ef55db77977f6c5449a..fa557372d600a0283663635ff198895cfad91709 100644 (file)
--- a/arch/s390/kvm/interrupt.c
+++ b/arch/s390/kvm/interrupt.c
@@ -213,6 +213,16 @@ static inline unsigned long pending_irqs(struct kvm_vcpu *vcpu)
               vcpu->arch.local_int.pending_irqs;
 }
 
+static inline int isc_to_irq_type(unsigned long isc)
+{
+       return IRQ_PEND_IO_ISC_0 + isc;
+}
+
+static inline int irq_type_to_isc(unsigned long irq_type)
+{
+       return irq_type - IRQ_PEND_IO_ISC_0;
+}
+
 static unsigned long disable_iscs(struct kvm_vcpu *vcpu,
                                   unsigned long active_mask)
 {
@@ -220,7 +230,7 @@ static unsigned long disable_iscs(struct kvm_vcpu *vcpu,
 
        for (i = 0; i <= MAX_ISC; i++)
                if (!(vcpu->arch.sie_block->gcr[6] & isc_to_isc_bits(i)))
-                       active_mask &= ~(1UL << (IRQ_PEND_IO_ISC_0 + i));
+                       active_mask &= ~(1UL << (isc_to_irq_type(i)));
 
        return active_mask;
 }
@@ -901,7 +911,7 @@ static int __must_check __deliver_io(struct kvm_vcpu *vcpu,
        fi = &vcpu->kvm->arch.float_int;
 
        spin_lock(&fi->lock);
-       isc_list = &fi->lists[irq_type - IRQ_PEND_IO_ISC_0];
+       isc_list = &fi->lists[irq_type_to_isc(irq_type)];
        inti = list_first_entry_or_null(isc_list,
                                        struct kvm_s390_interrupt_info,
                                        list);
@@ -1074,6 +1084,12 @@ void kvm_s390_vcpu_wakeup(struct kvm_vcpu *vcpu)
         * in kvm_vcpu_block without having the waitqueue set (polling)
         */
        vcpu->valid_wakeup = true;
+       /*
+        * This is mostly to document, that the read in swait_active could
+        * be moved before other stores, leading to subtle races.
+        * All current users do not store or use an atomic like update
+        */
+       smp_mb__after_atomic();
        if (swait_active(&vcpu->wq)) {
                /*
                 * The vcpu gave up the cpu voluntarily, mark it as a good
@@ -1395,7 +1411,7 @@ static struct kvm_s390_interrupt_info *get_io_int(struct kvm *kvm,
                list_del_init(&iter->list);
                fi->counters[FIRQ_CNTR_IO] -= 1;
                if (list_empty(isc_list))
-                       clear_bit(IRQ_PEND_IO_ISC_0 + isc, &fi->pending_irqs);
+                       clear_bit(isc_to_irq_type(isc), &fi->pending_irqs);
                spin_unlock(&fi->lock);
                return iter;
        }
@@ -1522,7 +1538,7 @@ static int __inject_io(struct kvm *kvm, struct kvm_s390_interrupt_info *inti)
        isc = int_word_to_isc(inti->io.io_int_word);
        list = &fi->lists[FIRQ_LIST_IO_ISC_0 + isc];
        list_add_tail(&inti->list, list);
-       set_bit(IRQ_PEND_IO_ISC_0 + isc, &fi->pending_irqs);
+       set_bit(isc_to_irq_type(isc), &fi->pending_irqs);
        spin_unlock(&fi->lock);
        return 0;
 }
@@ -2175,6 +2191,8 @@ static int clear_io_irq(struct kvm *kvm, struct kvm_device_attr *attr)
                return -EINVAL;
        if (copy_from_user(&schid, (void __user *) attr->addr, sizeof(schid)))
                return -EFAULT;
+       if (!schid)
+               return -EINVAL;
        kfree(kvm_s390_get_io_int(kvm, isc_mask, schid));
        /*
         * If userspace is conforming to the architecture, we can have at most