1Generic vcpu interface
2====================================
3
4The virtual cpu "device" also accepts the ioctls KVM_SET_DEVICE_ATTR,
5KVM_GET_DEVICE_ATTR, and KVM_HAS_DEVICE_ATTR. The interface uses the same struct
6kvm_device_attr as other devices, but targets VCPU-wide settings and controls.
7
8The groups and attributes per virtual cpu, if any, are architecture specific.
9
101. GROUP: KVM_ARM_VCPU_PMU_V3_CTRL
11Architectures: ARM64
12
131.1. ATTRIBUTE: KVM_ARM_VCPU_PMU_V3_IRQ
14Parameters: in kvm_device_attr.addr the address for PMU overflow interrupt is a
15            pointer to an int
16Returns: -EBUSY: The PMU overflow interrupt is already set
17         -ENXIO: The overflow interrupt not set when attempting to get it
18         -ENODEV: PMUv3 not supported
19         -EINVAL: Invalid PMU overflow interrupt number supplied or
20                  trying to set the IRQ number without using an in-kernel
21                  irqchip.
22
23A value describing the PMUv3 (Performance Monitor Unit v3) overflow interrupt
24number for this vcpu. This interrupt could be a PPI or SPI, but the interrupt
25type must be same for each vcpu. As a PPI, the interrupt number is the same for
26all vcpus, while as an SPI it must be a separate number per vcpu.
27
281.2 ATTRIBUTE: KVM_ARM_VCPU_PMU_V3_INIT
29Parameters: no additional parameter in kvm_device_attr.addr
30Returns: -ENODEV: PMUv3 not supported or GIC not initialized
31         -ENXIO: PMUv3 not properly configured or in-kernel irqchip not
32                 configured as required prior to calling this attribute
33         -EBUSY: PMUv3 already initialized
34
35Request the initialization of the PMUv3.  If using the PMUv3 with an in-kernel
36virtual GIC implementation, this must be done after initializing the in-kernel
37irqchip.
38
39
402. GROUP: KVM_ARM_VCPU_TIMER_CTRL
41Architectures: ARM,ARM64
42
432.1. ATTRIBUTE: KVM_ARM_VCPU_TIMER_IRQ_VTIMER
442.2. ATTRIBUTE: KVM_ARM_VCPU_TIMER_IRQ_PTIMER
45Parameters: in kvm_device_attr.addr the address for the timer interrupt is a
46            pointer to an int
47Returns: -EINVAL: Invalid timer interrupt number
48         -EBUSY:  One or more VCPUs has already run
49
50A value describing the architected timer interrupt number when connected to an
51in-kernel virtual GIC.  These must be a PPI (16 <= intid < 32).  Setting the
52attribute overrides the default values (see below).
53
54KVM_ARM_VCPU_TIMER_IRQ_VTIMER: The EL1 virtual timer intid (default: 27)
55KVM_ARM_VCPU_TIMER_IRQ_PTIMER: The EL1 physical timer intid (default: 30)
56
57Setting the same PPI for different timers will prevent the VCPUs from running.
58Setting the interrupt number on a VCPU configures all VCPUs created at that
59time to use the number provided for a given timer, overwriting any previously
60configured values on other VCPUs.  Userspace should configure the interrupt
61numbers on at least one VCPU after creating all VCPUs and before running any
62VCPUs.
63