1 .. SPDX-License-Identifier: GPL-2.0
2
3 ====================================
4 FLIC (floating interrupt controller)
5 ====================================
6
7 FLIC handles floating (non per-cpu) interrupts
8 machine check interruptions. All interrupts ar
9 pending interrupts. FLIC performs operations o
10
11 Only one FLIC instance may be instantiated.
12
13 FLIC provides support to
14 - add interrupts (KVM_DEV_FLIC_ENQUEUE)
15 - inspect currently pending interrupts (KVM_FL
16 - purge all pending floating interrupts (KVM_D
17 - purge one pending floating I/O interrupt (KV
18 - enable/disable for the guest transparent asy
19 - register and modify adapter interrupt source
20 - modify AIS (adapter-interruption-suppression
21 - inject adapter interrupts on a specified ada
22 - get/set all AIS mode states (KVM_DEV_FLIC_AI
23
24 Groups:
25 KVM_DEV_FLIC_ENQUEUE
26 Passes a buffer and length into the kernel
27 the list of pending interrupts.
28 attr->addr contains the pointer to the buf
29 the length of the buffer.
30 The format of the data structure kvm_s390_
31 is defined in usr/include/linux/kvm.h.
32
33 KVM_DEV_FLIC_GET_ALL_IRQS
34 Copies all floating interrupts into a buff
35 When the buffer is too small it returns -E
36 for userspace to try again with a bigger b
37
38 -ENOBUFS is returned when the allocation o
39 failed.
40
41 -EFAULT is returned when copying data to u
42 All interrupts remain pending, i.e. are no
43 currently pending interrupts.
44 attr->addr contains the userspace address
45 interrupt data will be copied.
46 attr->attr contains the size of the buffer
47
48 KVM_DEV_FLIC_CLEAR_IRQS
49 Simply deletes all elements from the list
50 interrupts. No interrupts are injected in
51
52 KVM_DEV_FLIC_CLEAR_IO_IRQ
53 Deletes one (if any) I/O interrupt for a s
54 subsystem identification word passed via t
55 attr->addr (address) and attr->attr (lengt
56
57 KVM_DEV_FLIC_APF_ENABLE
58 Enables async page faults for the guest. S
59 the host is allowed to handle this async a
60
61 KVM_DEV_FLIC_APF_DISABLE_WAIT
62 Disables async page faults for the guest a
63 async page faults are done. This is necess
64 for every init interrupt before migrating
65
66 KVM_DEV_FLIC_ADAPTER_REGISTER
67 Register an I/O adapter interrupt source.
68 describing the adapter to register::
69
70 struct kvm_s390_io_adapter {
71 __u32 id;
72 __u8 isc;
73 __u8 maskable;
74 __u8 swap;
75 __u8 flags;
76 };
77
78 id contains the unique id for the adapter,
79 to use, maskable whether this adapter may b
80 swap whether the indicators need to be byte
81 further characteristics of the adapter.
82
83 Currently defined values for 'flags' are:
84
85 - KVM_S390_ADAPTER_SUPPRESSIBLE: adapter is
86 (adapter-interrupt-suppression) facility.
87 the AIS capability is enabled.
88
89 Unknown flag values are ignored.
90
91
92 KVM_DEV_FLIC_ADAPTER_MODIFY
93 Modifies attributes of an existing I/O ada
94 a kvm_s390_io_adapter_req specifying the a
95
96 struct kvm_s390_io_adapter_req {
97 __u32 id;
98 __u8 type;
99 __u8 mask;
100 __u16 pad0;
101 __u64 addr;
102 };
103
104 id specifies the adapter and type the oper
105 are:
106
107 KVM_S390_IO_ADAPTER_MASK
108 mask or unmask the adapter, as specified
109
110 KVM_S390_IO_ADAPTER_MAP
111 This is now a no-op. The mapping is pure
112 KVM_S390_IO_ADAPTER_UNMAP
113 This is now a no-op. The mapping is pure
114
115 KVM_DEV_FLIC_AISM
116 modify the adapter-interruption-suppressio
117 AIS capability is enabled. Takes a kvm_s39
118
119 struct kvm_s390_ais_req {
120 __u8 isc;
121 __u16 mode;
122 };
123
124 isc contains the target I/O interruption s
125 adapter-interruption-suppression mode. The
126 currently supported:
127
128 - KVM_S390_AIS_MODE_ALL: ALL-Interruptions
129 is always allowed;
130 - KVM_S390_AIS_MODE_SINGLE: SINGLE-Interru
131 injection is only allowed once and the f
132 will be suppressed until the mode is set
133 or SINGLE-Interruption mode.
134
135 KVM_DEV_FLIC_AIRQ_INJECT
136 Inject adapter interrupts on a specified a
137 attr->attr contains the unique id for the
138 adapter-specific checks and actions.
139 For adapters subject to AIS, handle the ai
140 an isc according to the adapter-interrupti
141 that the AIS capability is enabled.
142
143 KVM_DEV_FLIC_AISM_ALL
144 Gets or sets the adapter-interruption-supp
145 a kvm_s390_ais_all describing::
146
147 struct kvm_s390_ais_all {
148 __u8 simm; /* Single-Interrupti
149 __u8 nimm; /* No-Interruption-M
150 };
151
152 simm contains Single-Interruption-Mode mas
153 No-Interruption-Mode mask for all ISCs. Ea
154 to an ISC (MSB0 bit 0 to ISC 0 and so on).
155 nimm bit presents AIS mode for a ISC.
156
157 KVM_DEV_FLIC_AISM_ALL is indicated by KVM_
158
159 Note: The KVM_SET_DEVICE_ATTR/KVM_GET_DEVICE_A
160 FLIC with an unknown group or attribute gives
161 ENXIO, as specified in the API documentation).
162 that a FLIC operation is unavailable based on
163 usage attempt.
164
165 .. note:: The KVM_DEV_FLIC_CLEAR_IO_IRQ ioctl
166 zero schid is specified.
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