win-pvdrivers

view common/include/public/vcpu.h @ 1106:2d392ecdd366

Fix race is xenvbd causing 30 second freeze under high load
author James Harper <james.harper@bendigoit.com.au>
date Tue Nov 11 23:08:11 2014 +1100 (2014-11-11)
parents 5712dede5a1b
children
line source
1 /******************************************************************************
2 * vcpu.h
3 *
4 * VCPU initialisation, query, and hotplug.
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a copy
7 * of this software and associated documentation files (the "Software"), to
8 * deal in the Software without restriction, including without limitation the
9 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
10 * sell copies of the Software, and to permit persons to whom the Software is
11 * furnished to do so, subject to the following conditions:
12 *
13 * The above copyright notice and this permission notice shall be included in
14 * all copies or substantial portions of the Software.
15 *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
19 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
21 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
22 * DEALINGS IN THE SOFTWARE.
23 *
24 * Copyright (c) 2005, Keir Fraser <keir@xensource.com>
25 */
27 #ifndef __XEN_PUBLIC_VCPU_H__
28 #define __XEN_PUBLIC_VCPU_H__
30 /*
31 * Prototype for this hypercall is:
32 * int vcpu_op(int cmd, int vcpuid, void *extra_args)
33 * @cmd == VCPUOP_??? (VCPU operation).
34 * @vcpuid == VCPU to operate on.
35 * @extra_args == Operation-specific extra arguments (NULL if none).
36 */
38 /*
39 * Initialise a VCPU. Each VCPU can be initialised only once. A
40 * newly-initialised VCPU will not run until it is brought up by VCPUOP_up.
41 *
42 * @extra_arg == pointer to vcpu_guest_context structure containing initial
43 * state for the VCPU.
44 */
45 #define VCPUOP_initialise 0
47 /*
48 * Bring up a VCPU. This makes the VCPU runnable. This operation will fail
49 * if the VCPU has not been initialised (VCPUOP_initialise).
50 */
51 #define VCPUOP_up 1
53 /*
54 * Bring down a VCPU (i.e., make it non-runnable).
55 * There are a few caveats that callers should observe:
56 * 1. This operation may return, and VCPU_is_up may return false, before the
57 * VCPU stops running (i.e., the command is asynchronous). It is a good
58 * idea to ensure that the VCPU has entered a non-critical loop before
59 * bringing it down. Alternatively, this operation is guaranteed
60 * synchronous if invoked by the VCPU itself.
61 * 2. After a VCPU is initialised, there is currently no way to drop all its
62 * references to domain memory. Even a VCPU that is down still holds
63 * memory references via its pagetable base pointer and GDT. It is good
64 * practise to move a VCPU onto an 'idle' or default page table, LDT and
65 * GDT before bringing it down.
66 */
67 #define VCPUOP_down 2
69 /* Returns 1 if the given VCPU is up. */
70 #define VCPUOP_is_up 3
72 /*
73 * Return information about the state and running time of a VCPU.
74 * @extra_arg == pointer to vcpu_runstate_info structure.
75 */
76 #define VCPUOP_get_runstate_info 4
77 struct vcpu_runstate_info {
78 /* VCPU's current state (RUNSTATE_*). */
79 int state;
80 /* When was current state entered (system time, ns)? */
81 uint64_t state_entry_time;
82 /*
83 * Time spent in each RUNSTATE_* (ns). The sum of these times is
84 * guaranteed not to drift from system time.
85 */
86 uint64_t time[4];
87 };
88 typedef struct vcpu_runstate_info vcpu_runstate_info_t;
89 DEFINE_XEN_GUEST_HANDLE(vcpu_runstate_info_t);
91 /* VCPU is currently running on a physical CPU. */
92 #define RUNSTATE_running 0
94 /* VCPU is runnable, but not currently scheduled on any physical CPU. */
95 #define RUNSTATE_runnable 1
97 /* VCPU is blocked (a.k.a. idle). It is therefore not runnable. */
98 #define RUNSTATE_blocked 2
100 /*
101 * VCPU is not runnable, but it is not blocked.
102 * This is a 'catch all' state for things like hotplug and pauses by the
103 * system administrator (or for critical sections in the hypervisor).
104 * RUNSTATE_blocked dominates this state (it is the preferred state).
105 */
106 #define RUNSTATE_offline 3
108 /*
109 * Register a shared memory area from which the guest may obtain its own
110 * runstate information without needing to execute a hypercall.
111 * Notes:
112 * 1. The registered address may be virtual or physical or guest handle,
113 * depending on the platform. Virtual address or guest handle should be
114 * registered on x86 systems.
115 * 2. Only one shared area may be registered per VCPU. The shared area is
116 * updated by the hypervisor each time the VCPU is scheduled. Thus
117 * runstate.state will always be RUNSTATE_running and
118 * runstate.state_entry_time will indicate the system time at which the
119 * VCPU was last scheduled to run.
120 * @extra_arg == pointer to vcpu_register_runstate_memory_area structure.
121 */
122 #define VCPUOP_register_runstate_memory_area 5
123 struct vcpu_register_runstate_memory_area {
124 union {
125 XEN_GUEST_HANDLE(vcpu_runstate_info_t) h;
126 struct vcpu_runstate_info *v;
127 uint64_t p;
128 } addr;
129 };
130 typedef struct vcpu_register_runstate_memory_area vcpu_register_runstate_memory_area_t;
131 DEFINE_XEN_GUEST_HANDLE(vcpu_register_runstate_memory_area_t);
133 /*
134 * Set or stop a VCPU's periodic timer. Every VCPU has one periodic timer
135 * which can be set via these commands. Periods smaller than one millisecond
136 * may not be supported.
137 */
138 #define VCPUOP_set_periodic_timer 6 /* arg == vcpu_set_periodic_timer_t */
139 #define VCPUOP_stop_periodic_timer 7 /* arg == NULL */
140 struct vcpu_set_periodic_timer {
141 uint64_t period_ns;
142 };
143 typedef struct vcpu_set_periodic_timer vcpu_set_periodic_timer_t;
144 DEFINE_XEN_GUEST_HANDLE(vcpu_set_periodic_timer_t);
146 /*
147 * Set or stop a VCPU's single-shot timer. Every VCPU has one single-shot
148 * timer which can be set via these commands.
149 */
150 #define VCPUOP_set_singleshot_timer 8 /* arg == vcpu_set_singleshot_timer_t */
151 #define VCPUOP_stop_singleshot_timer 9 /* arg == NULL */
152 struct vcpu_set_singleshot_timer {
153 uint64_t timeout_abs_ns; /* Absolute system time value in nanoseconds. */
154 uint32_t flags; /* VCPU_SSHOTTMR_??? */
155 };
156 typedef struct vcpu_set_singleshot_timer vcpu_set_singleshot_timer_t;
157 DEFINE_XEN_GUEST_HANDLE(vcpu_set_singleshot_timer_t);
159 /* Flags to VCPUOP_set_singleshot_timer. */
160 /* Require the timeout to be in the future (return -ETIME if it's passed). */
161 #define _VCPU_SSHOTTMR_future (0)
162 #define VCPU_SSHOTTMR_future (1U << _VCPU_SSHOTTMR_future)
164 /*
165 * Register a memory location in the guest address space for the
166 * vcpu_info structure. This allows the guest to place the vcpu_info
167 * structure in a convenient place, such as in a per-cpu data area.
168 * The pointer need not be page aligned, but the structure must not
169 * cross a page boundary.
170 *
171 * This may be called only once per vcpu.
172 */
173 #define VCPUOP_register_vcpu_info 10 /* arg == struct vcpu_info */
174 struct vcpu_register_vcpu_info {
175 uint64_t mfn; /* mfn of page to place vcpu_info */
176 uint32_t offset; /* offset within page */
177 uint32_t rsvd; /* unused */
178 };
179 typedef struct vcpu_register_vcpu_info vcpu_register_vcpu_info_t;
180 DEFINE_XEN_GUEST_HANDLE(vcpu_register_vcpu_info_t);
182 #endif /* __XEN_PUBLIC_VCPU_H__ */
184 /*
185 * Local variables:
186 * mode: C
187 * c-set-style: "BSD"
188 * c-basic-offset: 4
189 * tab-width: 4
190 * indent-tabs-mode: nil
191 * End:
192 */