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Diffstat (limited to 'kernel/include/linux/kvm_irqfd.h')
| -rw-r--r-- | kernel/include/linux/kvm_irqfd.h | 71 |
1 files changed, 71 insertions, 0 deletions
diff --git a/kernel/include/linux/kvm_irqfd.h b/kernel/include/linux/kvm_irqfd.h new file mode 100644 index 000000000..0c1de0509 --- /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 */ |