These changes are the raw update to linux-4.4.6-rt14. Kernel sources

[kvmfornfv.git] / kernel / include / linux / kvm_irqfd.h

diff --git a/kernel/include/linux/kvm_irqfd.h b/kernel/include/linux/kvm_irqfd.h
new file mode 100644 (file)
index 0000000..0c1de05
--- /dev/null
+++ b/kernel/include/linux/kvm_irqfd.h
@@ -0,0 +1,71 @@
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * irqfd: Allows an fd to be used to inject an interrupt to the guest
+ * Credit goes to Avi Kivity for the original idea.
+ */
+
+#ifndef __LINUX_KVM_IRQFD_H
+#define __LINUX_KVM_IRQFD_H
+
+#include <linux/kvm_host.h>
+#include <linux/poll.h>
+
+/*
+ * Resampling irqfds are a special variety of irqfds used to emulate
+ * level triggered interrupts.  The interrupt is asserted on eventfd
+ * trigger.  On acknowledgment through the irq ack notifier, the
+ * interrupt is de-asserted and userspace is notified through the
+ * resamplefd.  All resamplers on the same gsi are de-asserted
+ * together, so we don't need to track the state of each individual
+ * user.  We can also therefore share the same irq source ID.
+ */
+struct kvm_kernel_irqfd_resampler {
+       struct kvm *kvm;
+       /*
+        * List of resampling struct _irqfd objects sharing this gsi.
+        * RCU list modified under kvm->irqfds.resampler_lock
+        */
+       struct list_head list;
+       struct kvm_irq_ack_notifier notifier;
+       /*
+        * Entry in list of kvm->irqfd.resampler_list.  Use for sharing
+        * resamplers among irqfds on the same gsi.
+        * Accessed and modified under kvm->irqfds.resampler_lock
+        */
+       struct list_head link;
+};
+
+struct kvm_kernel_irqfd {
+       /* Used for MSI fast-path */
+       struct kvm *kvm;
+       wait_queue_t wait;
+       /* Update side is protected by irqfds.lock */
+       struct kvm_kernel_irq_routing_entry irq_entry;
+       seqcount_t irq_entry_sc;
+       /* Used for level IRQ fast-path */
+       int gsi;
+       struct work_struct inject;
+       /* The resampler used by this irqfd (resampler-only) */
+       struct kvm_kernel_irqfd_resampler *resampler;
+       /* Eventfd notified on resample (resampler-only) */
+       struct eventfd_ctx *resamplefd;
+       /* Entry in list of irqfds for a resampler (resampler-only) */
+       struct list_head resampler_link;
+       /* Used for setup/shutdown */
+       struct eventfd_ctx *eventfd;
+       struct list_head list;
+       poll_table pt;
+       struct work_struct shutdown;
+       struct irq_bypass_consumer consumer;
+       struct irq_bypass_producer *producer;
+};
+
+#endif /* __LINUX_KVM_IRQFD_H */