c05c4186bb
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>
37 lines
1.5 KiB
Plaintext
37 lines
1.5 KiB
Plaintext
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.
|