Linux kernel & device driver programming

Cross-Referenced Linux and Device Driver Code

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Version: [ 2.6.11.8 ] [ 2.6.25 ] [ 2.6.25.8 ] [ 2.6.31.13 ] Architecture: [ i386 ]
  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  */
 26 
 27 #ifndef __XEN_PUBLIC_VCPU_H__
 28 #define __XEN_PUBLIC_VCPU_H__
 29 
 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  */
 37 
 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
 46 
 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
 52 
 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
 68 
 69 /* Returns 1 if the given VCPU is up. */
 70 #define VCPUOP_is_up                             3
 71 
 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 
 89 /* VCPU is currently running on a physical CPU. */
 90 #define RUNSTATE_running  0
 91 
 92 /* VCPU is runnable, but not currently scheduled on any physical CPU. */
 93 #define RUNSTATE_runnable 1
 94 
 95 /* VCPU is blocked (a.k.a. idle). It is therefore not runnable. */
 96 #define RUNSTATE_blocked  2
 97 
 98 /*
 99  * VCPU is not runnable, but it is not blocked.
100  * This is a 'catch all' state for things like hotplug and pauses by the
101  * system administrator (or for critical sections in the hypervisor).
102  * RUNSTATE_blocked dominates this state (it is the preferred state).
103  */
104 #define RUNSTATE_offline  3
105 
106 /*
107  * Register a shared memory area from which the guest may obtain its own
108  * runstate information without needing to execute a hypercall.
109  * Notes:
110  *      1. The registered address may be virtual or physical, depending on the
111  *         platform. The virtual address should be registered on x86 systems.
112  *      2. Only one shared area may be registered per VCPU. The shared area is
113  *         updated by the hypervisor each time the VCPU is scheduled. Thus
114  *         runstate.state will always be RUNSTATE_running and
115  *         runstate.state_entry_time will indicate the system time at which the
116  *         VCPU was last scheduled to run.
117  * @extra_arg == pointer to vcpu_register_runstate_memory_area structure.
118  */
119 #define VCPUOP_register_runstate_memory_area 5
120 struct vcpu_register_runstate_memory_area {
121                 union {
122                                 struct vcpu_runstate_info *v;
123                                 uint64_t p;
124                 } addr;
125 };
126 
127 /*
128  * Set or stop a VCPU's periodic timer. Every VCPU has one periodic timer
129  * which can be set via these commands. Periods smaller than one millisecond
130  * may not be supported.
131  */
132 #define VCPUOP_set_periodic_timer        6 /* arg == vcpu_set_periodic_timer_t */
133 #define VCPUOP_stop_periodic_timer       7 /* arg == NULL */
134 struct vcpu_set_periodic_timer {
135                 uint64_t period_ns;
136 };
137 
138 /*
139  * Set or stop a VCPU's single-shot timer. Every VCPU has one single-shot
140  * timer which can be set via these commands.
141  */
142 #define VCPUOP_set_singleshot_timer      8 /* arg == vcpu_set_singleshot_timer_t */
143 #define VCPUOP_stop_singleshot_timer 9 /* arg == NULL */
144 struct vcpu_set_singleshot_timer {
145                 uint64_t timeout_abs_ns;
146                 uint32_t flags;                    /* VCPU_SSHOTTMR_??? */
147 };
148 
149 /* Flags to VCPUOP_set_singleshot_timer. */
150  /* Require the timeout to be in the future (return -ETIME if it's passed). */
151 #define _VCPU_SSHOTTMR_future (0)
152 #define VCPU_SSHOTTMR_future  (1U << _VCPU_SSHOTTMR_future)
153 
154 /*
155  * Register a memory location in the guest address space for the
156  * vcpu_info structure.  This allows the guest to place the vcpu_info
157  * structure in a convenient place, such as in a per-cpu data area.
158  * The pointer need not be page aligned, but the structure must not
159  * cross a page boundary.
160  */
161 #define VCPUOP_register_vcpu_info   10  /* arg == struct vcpu_info */
162 struct vcpu_register_vcpu_info {
163     uint64_t mfn;    /* mfn of page to place vcpu_info */
164     uint32_t offset; /* offset within page */
165     uint32_t rsvd;   /* unused */
166 };
167 
168 #endif /* __XEN_PUBLIC_VCPU_H__ */
169 
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