diff options
Diffstat (limited to 'arch/s390/kvm/interrupt.c')
| -rw-r--r-- | arch/s390/kvm/interrupt.c | 26 |
1 files changed, 22 insertions, 4 deletions
diff --git a/arch/s390/kvm/interrupt.c b/arch/s390/kvm/interrupt.c index 329b2843fee2..fa557372d600 100644 --- 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 |