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KVM: s390: add floating irq controller 

This patch adds a floating irq controller as a kvm_device.
It will be necessary 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@linux.vnet.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
This commit is contained in:
Jens Freimann 2013-10-07 16:13:45 +02:00 committed by Christian Borntraeger
parent 81aa8efe01
commit c05c4186bb
8 changed files with 317 additions and 56 deletions
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36
Documentation/virtual/kvm/devices/s390_flic.txt Normal file
View File

@ -0,0 +1,36 @@
FLIC (floating interrupt controller)
====================================
FLIC handles floating (non per-cpu) interrupts, i.e. I/O, service and some
machine check interruptions. All interrupts are stored in a per-vm list of
pending interrupts. FLIC performs operations on this list.
Only one FLIC instance may be instantiated.
FLIC provides support to
- add interrupts (KVM_DEV_FLIC_ENQUEUE)
- inspect currently pending interrupts (KVM_FLIC_GET_ALL_IRQS)
- purge all pending floating interrupts (KVM_DEV_FLIC_CLEAR_IRQS)
Groups:
KVM_DEV_FLIC_ENQUEUE
Passes a buffer and length into the kernel which are then injected into
the list of pending interrupts.
attr->addr contains the pointer to the buffer and attr->attr contains
the length of the buffer.
The format of the data structure kvm_s390_irq as it is copied from userspace
is defined in usr/include/linux/kvm.h.
KVM_DEV_FLIC_GET_ALL_IRQS
Copies all floating interrupts into a buffer provided by userspace.
When the buffer is too small it returns -ENOMEM, which is the indication
for userspace to try again with a bigger buffer.
All interrupts remain pending, i.e. are not deleted from the list of
currently pending interrupts.
attr->addr contains the userspace address of the buffer into which all
interrupt data will be copied.
attr->attr contains the size of the buffer in bytes.
KVM_DEV_FLIC_CLEAR_IRQS
Simply deletes all elements from the list of currently pending floating
interrupts. No interrupts are injected into the guest.

1
arch/s390/include/asm/kvm_host.h
View File

@ -243,6 +243,7 @@ struct kvm_arch{
struct sca_block *sca;
debug_info_t *dbf;
struct kvm_s390_float_interrupt float_int;
struct kvm_device *flic;
struct gmap *gmap;
int css_support;
};

14
arch/s390/include/uapi/asm/kvm.h
View File

@ -16,6 +16,20 @@
#define __KVM_S390
/* Device control API: s390-specific devices */
#define KVM_DEV_FLIC_GET_ALL_IRQS 1
#define KVM_DEV_FLIC_ENQUEUE 2
#define KVM_DEV_FLIC_CLEAR_IRQS 3
/*
* We can have up to 4*64k pending subchannels + 8 adapter interrupts,
* as well as up to ASYNC_PF_PER_VCPU*KVM_MAX_VCPUS pfault done interrupts.
* There are also sclp and machine checks. This gives us
* sizeof(kvm_s390_irq)*(4*65536+8+64*64+1+1) = 72 * 266250 = 19170000
* Lets round up to 8192 pages.
*/
#define KVM_S390_FLIC_MAX_BUFFER 0x2000000
/* for KVM_GET_REGS and KVM_SET_REGS */
struct kvm_regs {
/* general purpose regs for s390 */

314
arch/s390/kvm/interrupt.c
View File

@ -659,71 +659,19 @@ 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_interrupt_info *iter;
int sigcpu;
inti = kzalloc(sizeof(*inti), GFP_KERNEL);
if (!inti)
return -ENOMEM;
switch (s390int->type) {
case KVM_S390_INT_VIRTIO:
VM_EVENT(kvm, 5, "inject: virtio parm:%x,parm64:%llx",
s390int->parm, s390int->parm64);
inti->type = s390int->type;
inti->ext.ext_params = s390int->parm;
inti->ext.ext_params2 = s390int->parm64;
break;
case KVM_S390_INT_SERVICE:
VM_EVENT(kvm, 5, "inject: sclp parm:%x", s390int->parm);
inti->type = s390int->type;
inti->ext.ext_params = s390int->parm;
break;
case KVM_S390_PROGRAM_INT:
case KVM_S390_SIGP_STOP:
case KVM_S390_INT_EXTERNAL_CALL:
case KVM_S390_INT_EMERGENCY:
kfree(inti);
return -EINVAL;
case KVM_S390_MCHK:
VM_EVENT(kvm, 5, "inject: machine check parm64:%llx",
s390int->parm64);
inti->type = s390int->type;
inti->mchk.cr14 = s390int->parm; /* upper bits are not used */
inti->mchk.mcic = s390int->parm64;
break;
case KVM_S390_INT_IO_MIN...KVM_S390_INT_IO_MAX:
if (s390int->type & IOINT_AI_MASK)
VM_EVENT(kvm, 5, "%s", "inject: I/O (AI)");
else
VM_EVENT(kvm, 5, "inject: I/O css %x ss %x schid %04x",
s390int->type & IOINT_CSSID_MASK,
s390int->type & IOINT_SSID_MASK,
s390int->type & IOINT_SCHID_MASK);
inti->type = s390int->type;
inti->io.subchannel_id = s390int->parm >> 16;
inti->io.subchannel_nr = s390int->parm & 0x0000ffffu;
inti->io.io_int_parm = s390int->parm64 >> 32;
inti->io.io_int_word = s390int->parm64 & 0x00000000ffffffffull;
break;
default:
kfree(inti);
return -EINVAL;
}
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->type))
if (!is_ioint(inti->type)) {
list_add_tail(&inti->list, &fi->list);
else {
} else {
u64 isc_bits = int_word_to_isc_bits(inti->io.io_int_word);
/* Keep I/O interrupts sorted in isc order. */
@ -754,6 +702,56 @@ int kvm_s390_inject_vm(struct kvm *kvm,
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;
inti = kzalloc(sizeof(*inti), GFP_KERNEL);
if (!inti)
return -ENOMEM;
inti->type = s390int->type;
switch (inti->type) {
case KVM_S390_INT_VIRTIO:
VM_EVENT(kvm, 5, "inject: virtio parm:%x,parm64:%llx",
s390int->parm, s390int->parm64);
inti->ext.ext_params = s390int->parm;
inti->ext.ext_params2 = s390int->parm64;
break;
case KVM_S390_INT_SERVICE:
VM_EVENT(kvm, 5, "inject: sclp parm:%x", s390int->parm);
inti->ext.ext_params = s390int->parm;
break;
case KVM_S390_MCHK:
VM_EVENT(kvm, 5, "inject: machine check parm64:%llx",
s390int->parm64);
inti->mchk.cr14 = s390int->parm; /* upper bits are not used */
inti->mchk.mcic = s390int->parm64;
break;
case KVM_S390_INT_IO_MIN...KVM_S390_INT_IO_MAX:
if (inti->type & IOINT_AI_MASK)
VM_EVENT(kvm, 5, "%s", "inject: I/O (AI)");
else
VM_EVENT(kvm, 5, "inject: I/O css %x ss %x schid %04x",
s390int->type & IOINT_CSSID_MASK,
s390int->type & IOINT_SSID_MASK,
s390int->type & IOINT_SCHID_MASK);
inti->io.subchannel_id = s390int->parm >> 16;
inti->io.subchannel_nr = s390int->parm & 0x0000ffffu;
inti->io.io_int_parm = s390int->parm64 >> 32;
inti->io.io_int_word = s390int->parm64 & 0x00000000ffffffffull;
break;
default:
kfree(inti);
return -EINVAL;
}
trace_kvm_s390_inject_vm(s390int->type, s390int->parm, s390int->parm64,
2);
__inject_vm(kvm, inti);
return 0;
}
@ -841,3 +839,207 @@ 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;
struct kvm_s390_interrupt_info *n, *inti = NULL;
mutex_lock(&kvm->lock);
fi = &kvm->arch.float_int;
spin_lock(&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(&fi->lock);
mutex_unlock(&kvm->lock);
}
static inline int copy_irq_to_user(struct kvm_s390_interrupt_info *inti,
u8 *addr)
{
struct kvm_s390_irq __user *uptr = (struct kvm_s390_irq __user *) addr;
struct kvm_s390_irq irq = {0};
irq.type = inti->type;
switch (inti->type) {
case KVM_S390_INT_VIRTIO:
case KVM_S390_INT_SERVICE:
irq.u.ext = inti->ext;
break;
case KVM_S390_INT_IO_MIN...KVM_S390_INT_IO_MAX:
irq.u.io = inti->io;
break;
case KVM_S390_MCHK:
irq.u.mchk = inti->mchk;
break;
default:
return -EINVAL;
}
if (copy_to_user(uptr, &irq, sizeof(irq)))
return -EFAULT;
return 0;
}
static int get_all_floating_irqs(struct kvm *kvm, __u8 *buf, __u64 len)
{
struct kvm_s390_interrupt_info *inti;
struct kvm_s390_float_interrupt *fi;
int ret = 0;
int n = 0;
mutex_lock(&kvm->lock);
fi = &kvm->arch.float_int;
spin_lock(&fi->lock);
list_for_each_entry(inti, &fi->list, list) {
if (len < sizeof(struct kvm_s390_irq)) {
/* signal userspace to try again */
ret = -ENOMEM;
break;
}
ret = copy_irq_to_user(inti, buf);
if (ret)
break;
buf += sizeof(struct kvm_s390_irq);
len -= sizeof(struct kvm_s390_irq);
n++;
}
spin_unlock(&fi->lock);
mutex_unlock(&kvm->lock);
return ret < 0 ? ret : n;
}
static int flic_get_attr(struct kvm_device *dev, struct kvm_device_attr *attr)
{
int r;
switch (attr->group) {
case KVM_DEV_FLIC_GET_ALL_IRQS:
r = get_all_floating_irqs(dev->kvm, (u8 *) attr->addr,
attr->attr);
break;
default:
r = -EINVAL;
}
return r;
}
static inline int copy_irq_from_user(struct kvm_s390_interrupt_info *inti,
u64 addr)
{
struct kvm_s390_irq __user *uptr = (struct kvm_s390_irq __user *) addr;
void *target = NULL;
void __user *source;
u64 size;
if (get_user(inti->type, (u64 __user *)addr))
return -EFAULT;
switch (inti->type) {
case KVM_S390_INT_VIRTIO:
case KVM_S390_INT_SERVICE:
target = (void *) &inti->ext;
source = &uptr->u.ext;
size = sizeof(inti->ext);
break;
case KVM_S390_INT_IO_MIN...KVM_S390_INT_IO_MAX:
target = (void *) &inti->io;
source = &uptr->u.io;
size = sizeof(inti->io);
break;
case KVM_S390_MCHK:
target = (void *) &inti->mchk;
source = &uptr->u.mchk;
size = sizeof(inti->mchk);
break;
default:
return -EINVAL;
}
if (copy_from_user(target, source, size))
return -EFAULT;
return 0;
}
static int enqueue_floating_irq(struct kvm_device *dev,
struct kvm_device_attr *attr)
{
struct kvm_s390_interrupt_info *inti = NULL;
int r = 0;
int len = attr->attr;
if (len % sizeof(struct kvm_s390_irq) != 0)
return -EINVAL;
else if (len > KVM_S390_FLIC_MAX_BUFFER)
return -EINVAL;
while (len >= sizeof(struct kvm_s390_irq)) {
inti = kzalloc(sizeof(*inti), GFP_KERNEL);
if (!inti)
return -ENOMEM;
r = copy_irq_from_user(inti, attr->addr);
if (r) {
kfree(inti);
return r;
}
__inject_vm(dev->kvm, inti);
len -= sizeof(struct kvm_s390_irq);
attr->addr += sizeof(struct kvm_s390_irq);
}
return r;
}
static int flic_set_attr(struct kvm_device *dev, struct kvm_device_attr *attr)
{
int r = 0;
switch (attr->group) {
case KVM_DEV_FLIC_ENQUEUE:
r = enqueue_floating_irq(dev, attr);
break;
case KVM_DEV_FLIC_CLEAR_IRQS:
r = 0;
clear_floating_interrupts(dev->kvm);
break;
default:
r = -EINVAL;
}
return r;
}
static int flic_create(struct kvm_device *dev, u32 type)
{
if (!dev)
return -EINVAL;
if (dev->kvm->arch.flic)
return -EINVAL;
dev->kvm->arch.flic = dev;
return 0;
}
static void flic_destroy(struct kvm_device *dev)
{
dev->kvm->arch.flic = NULL;
kfree(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,
};

1
arch/s390/kvm/kvm-s390.c
View File

@ -157,6 +157,7 @@ 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:

1
include/linux/kvm_host.h
View File

@ -1064,6 +1064,7 @@ extern struct kvm_device_ops kvm_mpic_ops;
extern struct kvm_device_ops kvm_xics_ops;
extern struct kvm_device_ops kvm_vfio_ops;
extern struct kvm_device_ops kvm_arm_vgic_v2_ops;
extern struct kvm_device_ops kvm_flic_ops;
#ifdef CONFIG_HAVE_KVM_CPU_RELAX_INTERCEPT

1
include/uapi/linux/kvm.h
View File

@ -918,6 +918,7 @@ struct kvm_device_attr {
#define KVM_DEV_VFIO_GROUP_ADD 1
#define KVM_DEV_VFIO_GROUP_DEL 2
#define KVM_DEV_TYPE_ARM_VGIC_V2 5
#define KVM_DEV_TYPE_FLIC 6
/*
* ioctls for VM fds

5
virt/kvm/kvm_main.c
View File

@ -2283,6 +2283,11 @@ static int kvm_ioctl_create_device(struct kvm *kvm,
case KVM_DEV_TYPE_ARM_VGIC_V2:
ops = &kvm_arm_vgic_v2_ops;
break;
#endif
#ifdef CONFIG_S390
case KVM_DEV_TYPE_FLIC:
ops = &kvm_flic_ops;
break;
#endif
default:
return -ENODEV;