On Sun, Oct 13, 2013 at 11:39:55AM +0300, Gleb Natapov wrote:
> On Tue, Oct 08, 2013 at 04:54:55PM +0200, Christian Borntraeger wrote:
> > From: Jens Freimann <jfrei@xxxxxxxxxxxxxxxxxx>
> >
> > 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@xxxxxxxxxxxxxxxxxx>
> > Reviewed-by: Cornelia Huck <cornelia.huck@xxxxxxxxxx>
> > Signed-off-by: Christian Borntraeger <borntraeger@xxxxxxxxxx>
> > ---
> > Documentation/virtual/kvm/devices/s390_flic.txt | 36 +++
> > arch/s390/include/asm/kvm_host.h | 1 +
> > arch/s390/include/uapi/asm/kvm.h | 5 +
> > arch/s390/kvm/interrupt.c | 296 ++++++++++++++++++++----
> > arch/s390/kvm/kvm-s390.c | 1 +
> > include/linux/kvm_host.h | 1 +
> > include/uapi/linux/kvm.h | 1 +
> > virt/kvm/kvm_main.c | 5 +
> > 8 files changed, 295 insertions(+), 51 deletions(-)
> > create mode 100644 Documentation/virtual/kvm/devices/s390_flic.txt
> >
> > diff --git a/Documentation/virtual/kvm/devices/s390_flic.txt b/Documentation/virtual/kvm/devices/s390_flic.txt
> > new file mode 100644
> > index 0000000..06aef31
> > --- /dev/null
> > +++ b/Documentation/virtual/kvm/devices/s390_flic.txt
> > @@ -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/delete interrupts (KVM_DEV_FLIC_ENQUEUE and _DEQUEUE)
> > +- purge all pending floating interrupts (KVM_DEV_FLIC_CLEAR_IRQS)
> > +
> > +Groups:
> > + KVM_DEV_FLIC_ENQUEUE
> > + Adds one interrupt to the list of pending floating interrupts. Interrupts
> > + are taken from this list for injection into the guest. attr contains
> > + a struct kvm_s390_irq which contains all data relevant for
> > + interrupt injection.
> > + The format of the data structure kvm_s390_irq as it is copied from userspace
> > + is defined in usr/include/linux/kvm.h.
> > + For historic reasons list members are stored in a different data structure, i.e.
> > + we need to copy the relevant data into a struct kvm_s390_interrupt_info
> > + which can then be added to the list.
> > +
> > + KVM_DEV_FLIC_DEQUEUE
> > + Takes one element off the pending interrupts list and copies it into userspace.
> > + Dequeued interrupts are not injected into the guest.
> > + attr->addr contains the userspace address of a struct kvm_s390_irq.
> > + List elements are stored in the format of struct kvm_s390_interrupt_info
> > + (arch/s390/include/asm/kvm_host.h) and are copied into a struct kvm_s390_irq
> > + (usr/include/linux/kvm.h)
> > +
> Can interrupt be dequeued on real HW also? When this interface will be
> used?
We will it for migration. (See Christians mail)
> > + KVM_DEV_FLIC_CLEAR_IRQS
> > + Simply deletes all elements from the list of currently pending floating interrupts.
> > + No interrupts are injected into the guest.
> > diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h
> > index 78b6918..2d09c1d 100644
> > --- a/arch/s390/include/asm/kvm_host.h
> > +++ b/arch/s390/include/asm/kvm_host.h
> > @@ -237,6 +237,7 @@ 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;
> > };
> > 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 e7323cd..66478a0 100644
> > --- a/arch/s390/kvm/interrupt.c
> > +++ b/arch/s390/kvm/interrupt.c
> > @@ -659,53 +659,85 @@ 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;
> >
> > + mutex_lock(&kvm->lock);
> > + fi = &kvm->arch.float_int;
> > + spin_lock(&fi->lock);
> > + if (!is_ioint(inti->type)) {
> > + list_add_tail(&inti->list, &fi->list);
> > + } else {
> > + u64 isc_bits = int_word_to_isc_bits(inti->io.io_int_word);
> > +
> > + /* Keep I/O interrupts sorted in isc order. */
> > + list_for_each_entry(iter, &fi->list, list) {
> > + if (!is_ioint(iter->type))
> > + continue;
> > + if (int_word_to_isc_bits(iter->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;
> > +
> > inti = kzalloc(sizeof(*inti), GFP_KERNEL);
> > if (!inti)
> > return -ENOMEM;
> >
> > - switch (s390int->type) {
> > + 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->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)
> > + 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->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;
> > @@ -718,42 +750,7 @@ 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->type))
> > - list_add_tail(&inti->list, &fi->list);
> > - else {
> > - u64 isc_bits = int_word_to_isc_bits(inti->io.io_int_word);
> > -
> > - /* Keep I/O interrupts sorted in isc order. */
> > - list_for_each_entry(iter, &fi->list, list) {
> > - if (!is_ioint(iter->type))
> > - continue;
> > - if (int_word_to_isc_bits(iter->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;
> > }
> >
> > @@ -841,3 +838,200 @@ 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,
> > + u64 addr)
> > +{
> > + struct kvm_s390_irq __user *uptr = (struct kvm_s390_irq __user *) addr;
> > + void __user *target;
> > + void *source;
> > + u64 size;
> > + int r = 0;
> > +
> > + switch (inti->type) {
> > + case KVM_S390_INT_VIRTIO:
> > + case KVM_S390_INT_SERVICE:
> > + source = &inti->ext;
> > + target = &uptr->u.ext;
> > + size = sizeof(inti->ext);
> > + break;
> > + case KVM_S390_INT_IO_MIN...KVM_S390_INT_IO_MAX:
> > + source = &inti->io;
> > + target = &uptr->u.io;
> > + size = sizeof(inti->io);
> > + break;
> > + case KVM_S390_MCHK:
> > + source = &inti->mchk;
> > + target = &uptr->u.mchk;
> > + size = sizeof(inti->mchk);
> > + break;
> > + default:
> > + return -EINVAL;
> > + }
> > +
> > + r = put_user(inti->type, (u64 __user *) &uptr->type);
> > + if (copy_to_user(target, source, size))
> > + r = -EFAULT;
> > +
> > + return r;
> > +}
> > +
> > +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;
> > +
> > +
> > + mutex_lock(&kvm->lock);
> > + fi = &kvm->arch.float_int;
> > + spin_lock(&fi->lock);
> > + if (list_empty(&fi->list)) {
> > + mutex_unlock(&kvm->lock);
> > + spin_unlock(&fi->lock);
> > + return -ENODATA;
> > + }
> > + inti = list_first_entry(&fi->list, struct kvm_s390_interrupt_info, list);
> > + list_del(&inti->list);
> > + spin_unlock(&fi->lock);
> > + mutex_unlock(&kvm->lock);
> > +
> > + r = copy_irq_to_user(inti, addr);
> > +
> > + kfree(inti);
> > + return r;
> > +}
> > +
> > +static int flic_get_attr(struct kvm_device *dev, struct kvm_device_attr *attr)
> > +{
> > + int r;
> > +
> > + switch (attr->group) {
> > + case KVM_DEV_FLIC_DEQUEUE:
> > + r = dequeue_floating_irq(dev->kvm, attr->addr);
> > + 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;
> > + int r = 0;
> > +
> > + 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:
> > + r = -EINVAL;
> > + return r;
> > + }
> > +
> > + if (copy_from_user(target, source, size))
> > + r = -EFAULT;
> > +
> > + return r;
> > +}
> > +
> > +static int enqueue_floating_irq(struct kvm_device *dev,
> > + struct kvm_device_attr *attr)
> > +{
> > + struct kvm_s390_interrupt_info *inti = NULL;
> > + int r = 0;
> > +
> > + 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);
> > +
> > + 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;
> You need to call kfree(dev) here. There is a patch that moves this free
> to a common code, but it is not yet in.
Ok, I wasn't aware of this. Will fix.
regards
Jens
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