linux.git/virt/kvm/eventfd.c, branch v4.12

KVM: x86: rename kvm_vcpu_request_scan_ioapic()

2017-04-12T18:17:14+00:00

Let's rename it into a proper arch specific callback.

Signed-off-by: David Hildenbrand 
Signed-off-by: Radim Krčmář

KVM: kvm_io_bus_unregister_dev() should never fail

2017-03-23T18:02:25+00:00

No caller currently checks the return value of
kvm_io_bus_unregister_dev(). This is evil, as all callers silently go on
freeing their device. A stale reference will remain in the io_bus,
getting at least used again, when the iobus gets teared down on
kvm_destroy_vm() - leading to use after free errors.

There is nothing the callers could do, except retrying over and over
again.

So let's simply remove the bus altogether, print an error and make
sure no one can access this broken bus again (returning -ENOMEM on any
attempt to access it).

Fixes: e93f8a0f821e ("KVM: convert io_bus to SRCU")
Cc: stable@vger.kernel.org # 3.4+
Reported-by: Dmitry Vyukov 
Reviewed-by: Cornelia Huck 
Signed-off-by: David Hildenbrand 
Signed-off-by: Paolo Bonzini

KVM: fix OOPS on flush_work

2016-10-26T12:06:51+00:00

The conversion done by commit 3706feacd007 ("KVM: Remove deprecated
create_singlethread_workqueue") is broken.  It flushes a single work
item &irqfd->shutdown instead of all of them, and even worse if there
is no irqfd on the list then you get a NULL pointer dereference.
Revert the virt/kvm/eventfd.c part of that patch; to avoid the
deprecated function, just allocate our own workqueue---it does
not even have to be unbound---with alloc_workqueue.

Fixes: 3706feacd007
Reviewed-by: Cornelia Huck 
Signed-off-by: Paolo Bonzini

KVM: Remove deprecated create_singlethread_workqueue

2016-09-07T17:34:28+00:00

The workqueue "irqfd_cleanup_wq" queues a single work item
&irqfd->shutdown and hence doesn't require ordering. It is a host-wide
workqueue for issuing deferred shutdown requests aggregated from all
vm* instances. It is not being used on a memory reclaim path.
Hence, it has been converted to use system_wq.
The work item has been flushed in kvm_irqfd_release().

The workqueue "wqueue" queues a single work item &timer->expired
and hence doesn't require ordering. Also, it is not being used on
a memory reclaim path. Hence, it has been converted to use system_wq.

System workqueues have been able to handle high level of concurrency
for a long time now and hence it's not required to have a singlethreaded
workqueue just to gain concurrency. Unlike a dedicated per-cpu workqueue
created with create_singlethread_workqueue(), system_wq allows multiple
work items to overlap executions even on the same CPU; however, a
per-cpu workqueue doesn't have any CPU locality or global ordering
guarantee unless the target CPU is explicitly specified and thus the
increase of local concurrency shouldn't make any difference.

Signed-off-by: Bhaktipriya Shridhar 
Signed-off-by: Paolo Bonzini

kvm: Conditionally register IRQ bypass consumer

2016-05-11T20:37:55+00:00

If we don't support a mechanism for bypassing IRQs, don't register as
a consumer.  This eliminates meaningless dev_info()s when the connect
fails between producer and consumer, such as on AMD systems where
kvm_x86_ops->update_pi_irte is not implemented

Signed-off-by: Alex Williamson 
Signed-off-by: Paolo Bonzini

KVM: x86: merge kvm_arch_set_irq with kvm_set_msi_inatomic

2015-11-04T15:24:35+00:00

We do not want to do too much work in atomic context, in particular
not walking all the VCPUs of the virtual machine.  So we want
to distinguish the architecture-specific injection function for irqfd
from kvm_set_msi.  Since it's still empty, reuse the newly added
kvm_arch_set_irq and rename it to kvm_arch_set_irq_inatomic.

Reviewed-by: Radim Krčmář 
Signed-off-by: Paolo Bonzini

kvm/eventfd: add arch-specific set_irq

2015-10-16T08:34:29+00:00

Allow for arch-specific interrupt types to be set.  For that, add
kvm_arch_set_irq() which takes interrupt type-specific action if it
recognizes the interrupt type given, and -EWOULDBLOCK otherwise.

The default implementation always returns -EWOULDBLOCK.

Signed-off-by: Andrey Smetanin 
Reviewed-by: Roman Kagan 
Signed-off-by: Denis V. Lunev 
CC: Vitaly Kuznetsov 
CC: "K. Y. Srinivasan" 
CC: Gleb Natapov 
CC: Paolo Bonzini 
Signed-off-by: Paolo Bonzini

kvm/eventfd: factor out kvm_notify_acked_gsi()

2015-10-16T08:34:29+00:00

Factor out kvm_notify_acked_gsi() helper to iterate over EOI listeners
and notify those matching the given gsi.

It will be reused in the upcoming Hyper-V SynIC implementation.

Signed-off-by: Andrey Smetanin 
Reviewed-by: Roman Kagan 
Signed-off-by: Denis V. Lunev 
CC: Vitaly Kuznetsov 
CC: "K. Y. Srinivasan" 
CC: Gleb Natapov 
CC: Paolo Bonzini 
Signed-off-by: Paolo Bonzini

kvm/eventfd: avoid loop inside irqfd_update()

2015-10-16T08:34:28+00:00

The loop(for) inside irqfd_update() is unnecessary
because any other value for irq_entry.type will just trigger
schedule_work(&irqfd->inject) in irqfd_wakeup.

Signed-off-by: Andrey Smetanin 
Reviewed-by: Roman Kagan 
Signed-off-by: Denis V. Lunev 
CC: Vitaly Kuznetsov 
CC: "K. Y. Srinivasan" 
CC: Gleb Natapov 
CC: Paolo Bonzini 
Signed-off-by: Paolo Bonzini

KVM: Add an arch specific hooks in 'struct kvm_kernel_irqfd'

2015-10-01T13:06:47+00:00

This patch adds an arch specific hooks 'arch_update' in
'struct kvm_kernel_irqfd'. On Intel side, it is used to
update the IRTE when VT-d posted-interrupts is used.

Signed-off-by: Feng Wu 
Reviewed-by: Alex Williamson 
Signed-off-by: Paolo Bonzini