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Documentation / virtual / kvm / devices / vcpu.txt


Based on kernel version 4.16.1. Page generated on 2018-04-09 11:53 EST.

1	Generic vcpu interface
2	====================================
3	
4	The virtual cpu "device" also accepts the ioctls KVM_SET_DEVICE_ATTR,
5	KVM_GET_DEVICE_ATTR, and KVM_HAS_DEVICE_ATTR. The interface uses the same struct
6	kvm_device_attr as other devices, but targets VCPU-wide settings and controls.
7	
8	The groups and attributes per virtual cpu, if any, are architecture specific.
9	
10	1. GROUP: KVM_ARM_VCPU_PMU_V3_CTRL
11	Architectures: ARM64
12	
13	1.1. ATTRIBUTE: KVM_ARM_VCPU_PMU_V3_IRQ
14	Parameters: in kvm_device_attr.addr the address for PMU overflow interrupt is a
15	            pointer to an int
16	Returns: -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	
23	A value describing the PMUv3 (Performance Monitor Unit v3) overflow interrupt
24	number for this vcpu. This interrupt could be a PPI or SPI, but the interrupt
25	type must be same for each vcpu. As a PPI, the interrupt number is the same for
26	all vcpus, while as an SPI it must be a separate number per vcpu.
27	
28	1.2 ATTRIBUTE: KVM_ARM_VCPU_PMU_V3_INIT
29	Parameters: no additional parameter in kvm_device_attr.addr
30	Returns: -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	
35	Request the initialization of the PMUv3.  If using the PMUv3 with an in-kernel
36	virtual GIC implementation, this must be done after initializing the in-kernel
37	irqchip.
38	
39	
40	2. GROUP: KVM_ARM_VCPU_TIMER_CTRL
41	Architectures: ARM,ARM64
42	
43	2.1. ATTRIBUTE: KVM_ARM_VCPU_TIMER_IRQ_VTIMER
44	2.2. ATTRIBUTE: KVM_ARM_VCPU_TIMER_IRQ_PTIMER
45	Parameters: in kvm_device_attr.addr the address for the timer interrupt is a
46	            pointer to an int
47	Returns: -EINVAL: Invalid timer interrupt number
48	         -EBUSY:  One or more VCPUs has already run
49	
50	A value describing the architected timer interrupt number when connected to an
51	in-kernel virtual GIC.  These must be a PPI (16 <= intid < 32).  Setting the
52	attribute overrides the default values (see below).
53	
54	KVM_ARM_VCPU_TIMER_IRQ_VTIMER: The EL1 virtual timer intid (default: 27)
55	KVM_ARM_VCPU_TIMER_IRQ_PTIMER: The EL1 physical timer intid (default: 30)
56	
57	Setting the same PPI for different timers will prevent the VCPUs from running.
58	Setting the interrupt number on a VCPU configures all VCPUs created at that
59	time to use the number provided for a given timer, overwriting any previously
60	configured values on other VCPUs.  Userspace should configure the interrupt
61	numbers on at least one VCPU after creating all VCPUs and before running any
62	VCPUs.
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