This patch adds a floating irq controller as a kvm_device.
It will be necesary for migration of floating interrupts as well
as for hardening the reset code by allowing user space to explicitly
remove all pending floating interrupts.
Signed-off-by: Jens Freimann <jfrei@xxxxxxxxxxxxxxxxxx>
---
arch/s390/include/uapi/asm/kvm.h | 5 +
arch/s390/kvm/interrupt.c | 192 +++++++++++++++++++++++++++++++--------
arch/s390/kvm/kvm-s390.c | 1 +
include/linux/kvm_host.h | 1 +
include/uapi/linux/kvm.h | 1 +
virt/kvm/kvm_main.c | 3 +
6 files changed, 163 insertions(+), 40 deletions(-)
diff --git a/arch/s390/include/uapi/asm/kvm.h b/arch/s390/include/uapi/asm/kvm.h
index d25da59..33d52b8 100644
--- a/arch/s390/include/uapi/asm/kvm.h
+++ b/arch/s390/include/uapi/asm/kvm.h
@@ -16,6 +16,11 @@
#define __KVM_S390
+/* Device control API: s390-specific devices */
+#define KVM_DEV_FLIC_DEQUEUE 1
+#define KVM_DEV_FLIC_ENQUEUE 2
+#define KVM_DEV_FLIC_CLEAR_IRQS 3
+
/* for KVM_GET_REGS and KVM_SET_REGS */
struct kvm_regs {
/* general purpose regs for s390 */
diff --git a/arch/s390/kvm/interrupt.c b/arch/s390/kvm/interrupt.c
index 25cf71d..065a402 100644
--- a/arch/s390/kvm/interrupt.c
+++ b/arch/s390/kvm/interrupt.c
@@ -656,15 +656,57 @@ struct kvm_s390_interrupt_info *kvm_s390_get_io_int(struct kvm *kvm,
return inti;
}
-int kvm_s390_inject_vm(struct kvm *kvm,
- struct kvm_s390_interrupt *s390int)
+static void __inject_vm(struct kvm *kvm, struct kvm_s390_interrupt_info *inti)
{
struct kvm_s390_local_interrupt *li;
struct kvm_s390_float_interrupt *fi;
- struct kvm_s390_interrupt_info *inti, *iter;
- struct kvm_s390_irq *irq;
+ struct kvm_s390_interrupt_info *iter;
int sigcpu;
+ mutex_lock(&kvm->lock);
+ fi = &kvm->arch.float_int;
+ spin_lock(&fi->lock);
+ if (!is_ioint(inti->irq.type))
+ list_add_tail(&inti->list, &fi->list);
+ else {
+ u64 isc_bits = int_word_to_isc_bits(inti->irq.io.io_int_word);
+
+ /* Keep I/O interrupts sorted in isc order. */
+ list_for_each_entry(iter, &fi->list, list) {
+ if (!is_ioint(iter->irq.type))
+ continue;
+ if (int_word_to_isc_bits(iter->irq.io.io_int_word)
+ <= isc_bits)
+ continue;
+ break;
+ }
+ list_add_tail(&inti->list, &iter->list);
+ }
+ atomic_set(&fi->active, 1);
+ sigcpu = find_first_bit(fi->idle_mask, KVM_MAX_VCPUS);
+ if (sigcpu == KVM_MAX_VCPUS) {
+ do {
+ sigcpu = fi->next_rr_cpu++;
+ if (sigcpu == KVM_MAX_VCPUS)
+ sigcpu = fi->next_rr_cpu = 0;
+ } while (fi->local_int[sigcpu] == NULL);
+ }
+ li = fi->local_int[sigcpu];
+ spin_lock_bh(&li->lock);
+ atomic_set_mask(CPUSTAT_EXT_INT, li->cpuflags);
+ if (waitqueue_active(li->wq))
+ wake_up_interruptible(li->wq);
+ spin_unlock_bh(&li->lock);
+ spin_unlock(&fi->lock);
+ mutex_unlock(&kvm->lock);
+}
+
+int kvm_s390_inject_vm(struct kvm *kvm,
+ struct kvm_s390_interrupt *s390int)
+{
+ struct kvm_s390_interrupt_info *inti;
+ struct kvm_s390_irq *irq;
+
inti = kzalloc(sizeof(*inti), GFP_KERNEL);
if (!inti)
return -ENOMEM;
@@ -712,42 +754,7 @@ int kvm_s390_inject_vm(struct kvm *kvm,
}
trace_kvm_s390_inject_vm(s390int->type, s390int->parm, s390int->parm64, 2);
- mutex_lock(&kvm->lock);
- fi = &kvm->arch.float_int;
- spin_lock(&fi->lock);
- if (!is_ioint(inti->irq.type))
- list_add_tail(&inti->list, &fi->list);
- else {
- u64 isc_bits = int_word_to_isc_bits(inti->irq.io.io_int_word);
-
- /* Keep I/O interrupts sorted in isc order. */
- list_for_each_entry(iter, &fi->list, list) {
- if (!is_ioint(iter->irq.type))
- continue;
- if (int_word_to_isc_bits(iter->irq.io.io_int_word)
- <= isc_bits)
- continue;
- break;
- }
- list_add_tail(&inti->list, &iter->list);
- }
- atomic_set(&fi->active, 1);
- sigcpu = find_first_bit(fi->idle_mask, KVM_MAX_VCPUS);
- if (sigcpu == KVM_MAX_VCPUS) {
- do {
- sigcpu = fi->next_rr_cpu++;
- if (sigcpu == KVM_MAX_VCPUS)
- sigcpu = fi->next_rr_cpu = 0;
- } while (fi->local_int[sigcpu] == NULL);
- }
- li = fi->local_int[sigcpu];
- spin_lock_bh(&li->lock);
- atomic_set_mask(CPUSTAT_EXT_INT, li->cpuflags);
- if (waitqueue_active(li->wq))
- wake_up_interruptible(li->wq);
- spin_unlock_bh(&li->lock);
- spin_unlock(&fi->lock);
- mutex_unlock(&kvm->lock);
+ __inject_vm(kvm, inti);
return 0;
}
@@ -835,3 +842,108 @@ int kvm_s390_inject_vcpu(struct kvm_vcpu *vcpu,
mutex_unlock(&vcpu->kvm->lock);
return 0;
}
+
+static void clear_floating_interrupts(struct kvm *kvm)
+{
+ struct kvm_s390_float_interrupt *fi = &kvm->arch.float_int;
+ struct kvm_s390_interrupt_info *n, *inti = NULL;
+
+ if (atomic_read(&fi->active)) {
+ spin_lock_bh(&fi->lock);
+ list_for_each_entry_safe(inti, n, &fi->list, list) {
+ list_del(&inti->list);
+ kfree(inti);
+ }
+ atomic_set(&fi->active, 0);
+ spin_unlock_bh(&fi->lock);
+ }
+}
+
+
+static int dequeue_floating_irq(struct kvm *kvm, __u64 addr)
+{
+ struct kvm_s390_interrupt_info *inti;
+ struct kvm_s390_float_interrupt *fi;
+ int r = 0;
+
+ fi = &kvm->arch.float_int;
+ mutex_lock(&kvm->lock);
+ spin_lock(&fi->lock);
+
+ if (!list_empty(&fi->list)) {
+ inti = list_first_entry(&fi->list,
+ struct kvm_s390_interrupt_info, list);
+ list_del(&inti->list);
+ if (copy_to_user((void *) addr, &inti->irq, sizeof(inti->irq)))
+ r = -EFAULT;
+ } else
+ r = -ENODATA;
+
+ spin_unlock(&fi->lock);
+ mutex_unlock(&kvm->lock);
+
+ return r;
+}
+
+static int flic_get_attr(struct kvm_device *dev, struct kvm_device_attr *attr)
+{
+ int r = 0;
+
+ switch (attr->group) {
+ case KVM_DEV_FLIC_DEQUEUE:
+ r = dequeue_floating_irq(dev->kvm, attr->addr);
+ break;
+ default:
+ r = -EINVAL;
+ }
+
+ return r;
+}
+
+static int flic_set_attr(struct kvm_device *dev, struct kvm_device_attr *attr)
+{
+ int r;
+
+ switch (attr->group) {
+ case KVM_DEV_FLIC_ENQUEUE: {
+ struct kvm_s390_irq *s390irq;
+ struct kvm_s390_interrupt_info *inti;
+ inti = kzalloc(sizeof(*inti), GFP_KERNEL);
+ if (!inti)
+ return -ENOMEM;
+ s390irq = kzalloc(sizeof(*s390irq), GFP_KERNEL);
+ if (!s390irq)
+ return -ENOMEM;
+ if (copy_from_user(s390irq, (u64 __user *)attr->addr,
+ sizeof(s390irq)))
+ return -EFAULT;
+ inti->irq = *s390irq;
+ __inject_vm(dev->kvm, inti);
+ }
+ break;
+ case KVM_DEV_FLIC_CLEAR_IRQS:
+ clear_floating_interrupts(dev->kvm);
+ default:
+ r = -EINVAL;
+ }
+
+ return r;
+}
+
+static int flic_create(struct kvm_device *dev, u32 type)
+{
+ return 0;
+}
+
+static void flic_destroy(struct kvm_device *dev)
+{
+}
+
+/* s390 floating irq controller (flic) */
+struct kvm_device_ops kvm_flic_ops = {
+ .name = "kvm-flic",
+ .get_attr = flic_get_attr,
+ .set_attr = flic_set_attr,
+ .create = flic_create,
+ .destroy = flic_destroy,
+};
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index ba694d2..b85a3f0 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -150,6 +150,7 @@ int kvm_dev_ioctl_check_extension(long ext)
case KVM_CAP_ENABLE_CAP:
case KVM_CAP_S390_CSS_SUPPORT:
case KVM_CAP_IOEVENTFD:
+ case KVM_CAP_DEVICE_CTRL:
r = 1;
break;
case KVM_CAP_NR_VCPUS:
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index a63d83e..fa517dd 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -1052,6 +1052,7 @@ struct kvm_device *kvm_device_from_filp(struct file *filp);
extern struct kvm_device_ops kvm_mpic_ops;
extern struct kvm_device_ops kvm_xics_ops;
+extern struct kvm_device_ops kvm_flic_ops;
#ifdef CONFIG_HAVE_KVM_CPU_RELAX_INTERCEPT
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index d6a1584..c5aa7ce 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -904,6 +904,7 @@ struct kvm_device_attr {
#define KVM_DEV_TYPE_FSL_MPIC_20 1
#define KVM_DEV_TYPE_FSL_MPIC_42 2
#define KVM_DEV_TYPE_XICS 3
+#define KVM_DEV_TYPE_FLIC 4
/*
* ioctls for VM fds
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 1580dd4..cb017eb 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -2282,6 +2282,9 @@ static int kvm_ioctl_create_device(struct kvm *kvm,
ops = &kvm_xics_ops;
break;
#endif
+ case KVM_DEV_TYPE_FLIC:
+ ops = &kvm_flic_ops;
+ break;
default:
return -ENODEV;
}
--
1.8.0.1
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