Documentation/virt/kvm/devices/arm-vgic-v5.rst

Source file repositories/reference/linux-study-clean/Documentation/virt/kvm/devices/arm-vgic-v5.rst

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Linux kernel
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Documentation/virt/kvm/devices/arm-vgic-v5.rst
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Support Tooling And Documentation
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Documentation
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Support Tooling And Documentation: documentation
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Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.

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.. SPDX-License-Identifier: GPL-2.0

====================================================
ARM Virtual Generic Interrupt Controller v5 (VGICv5)
====================================================


Device types supported:
  - KVM_DEV_TYPE_ARM_VGIC_V5     ARM Generic Interrupt Controller v5.0

Only one VGIC instance may be instantiated through this API.  The created VGIC
will act as the VM interrupt controller, requiring emulated user-space devices
to inject interrupts to the VGIC instead of directly to CPUs.

Creating a guest GICv5 device requires a GICv5 host.  The current VGICv5 device
only supports PPI interrupts.  These can either be injected from emulated
in-kernel devices (such as the Arch Timer, or PMU), or via the KVM_IRQ_LINE
ioctl.

Groups:
  KVM_DEV_ARM_VGIC_GRP_CTRL
   Attributes:

    KVM_DEV_ARM_VGIC_CTRL_INIT
      request the initialization of the VGIC, no additional parameter in
      kvm_device_attr.addr. Must be called after all VCPUs have been created.

   KVM_DEV_ARM_VGIC_USERSPACE_PPIS
      request the mask of userspace-drivable PPIs. Only a subset of the PPIs can
      be directly driven from userspace with GICv5, and the returned mask
      informs userspace of which it is allowed to drive via KVM_IRQ_LINE.

      Userspace must allocate and point to __u64[2] of data in
      kvm_device_attr.addr. When this call returns, the provided memory will be
      populated with the userspace PPI mask. The lower __u64 contains the mask
      for the lower 64 PPIS, with the remaining 64 being in the second __u64.

      This is a read-only attribute, and cannot be set. Attempts to set it are
      rejected.

  Errors:

    =======  ========================================================
    -ENXIO   VGIC not properly configured as required prior to calling
             this attribute
    -ENODEV  no online VCPU
    -ENOMEM  memory shortage when allocating vgic internal data
    -EFAULT  Invalid guest ram access
    -EBUSY   One or more VCPUS are running
    =======  ========================================================

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