kvm/devices/arm-vgic-its.rst

4 ARM Virtual Interrupt Translation Service (ITS)
10 The ITS allows MSI(-X) interrupts to be injected into guests. This extension is
11 optional.  Creating a virtual ITS controller also requires a host GICv3 (see
12 arm-vgic-v3.txt), but does not depend on having physical ITS controllers.
14 There can be multiple ITS controllers per guest, each of them has to have
26       Base address in the guest physical address space of the GICv3 ITS
37     -ENODEV  Incorrect attribute or the ITS is not supported.
46       request the initialization of the ITS, no additional parameter in
50       reset the ITS, no additional parameter in kvm_device_attr.addr.
51       See "ITS Reset State" section.
54       save the ITS table data into guest RAM, at the location provisioned
64       restore the ITS tables from guest RAM to ITS internal structures.
66       The GICV3 must be restored before the ITS and all ITS registers but
67       the GITS_CTLR must be restored before restoring the ITS tables.
73       The expected ordering when restoring the GICv3/ITS is described in section
74       "ITS Restore Sequence".
79      -ENXIO  ITS not properly configured as required prior to setting
81     -ENOMEM  Memory shortage when allocating ITS internal data
85     -EACCES  The virtual ITS is backed by a physical GICv4 ITS, and the
94       ITS register, relative to the ITS control frame base address
106         ITS. Also it must be restored after GITS_CBASER since a write to
126 ITS Restore Sequence:
129 The following ordering must be followed when restoring the GIC and the ITS:
133 c) provide the ITS base address
135 d) restore the ITS in the following order:
139      3. Load the ITS table data (KVM_DEV_ARM_ITS_RESTORE_TABLES)
144 ITS Table ABI REV0:
198 ITS Reset State:
201 RESET returns the ITS to the same state that it was when first created and
205 - The ITS is not enabled and quiescent
211 - The ABI version is unchanged and remains the one set when the ITS