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xen.h
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1 /******************************************************************************
2  * xen.h
3  *
4  * Guest OS interface to Xen.
5  *
6  * Copyright (c) 2004, K A Fraser
7  */
8 
9 #ifndef __XEN_PUBLIC_XEN_H__
10 #define __XEN_PUBLIC_XEN_H__
11 
12 #include <asm/xen/interface.h>
13 
14 /*
15  * XEN "SYSTEM CALLS" (a.k.a. HYPERCALLS).
16  */
17 
18 /*
19  * x86_32: EAX = vector; EBX, ECX, EDX, ESI, EDI = args 1, 2, 3, 4, 5.
20  * EAX = return value
21  * (argument registers may be clobbered on return)
22  * x86_64: RAX = vector; RDI, RSI, RDX, R10, R8, R9 = args 1, 2, 3, 4, 5, 6.
23  * RAX = return value
24  * (argument registers not clobbered on return; RCX, R11 are)
25  */
26 #define __HYPERVISOR_set_trap_table 0
27 #define __HYPERVISOR_mmu_update 1
28 #define __HYPERVISOR_set_gdt 2
29 #define __HYPERVISOR_stack_switch 3
30 #define __HYPERVISOR_set_callbacks 4
31 #define __HYPERVISOR_fpu_taskswitch 5
32 #define __HYPERVISOR_sched_op_compat 6
33 #define __HYPERVISOR_dom0_op 7
34 #define __HYPERVISOR_set_debugreg 8
35 #define __HYPERVISOR_get_debugreg 9
36 #define __HYPERVISOR_update_descriptor 10
37 #define __HYPERVISOR_memory_op 12
38 #define __HYPERVISOR_multicall 13
39 #define __HYPERVISOR_update_va_mapping 14
40 #define __HYPERVISOR_set_timer_op 15
41 #define __HYPERVISOR_event_channel_op_compat 16
42 #define __HYPERVISOR_xen_version 17
43 #define __HYPERVISOR_console_io 18
44 #define __HYPERVISOR_physdev_op_compat 19
45 #define __HYPERVISOR_grant_table_op 20
46 #define __HYPERVISOR_vm_assist 21
47 #define __HYPERVISOR_update_va_mapping_otherdomain 22
48 #define __HYPERVISOR_iret 23 /* x86 only */
49 #define __HYPERVISOR_vcpu_op 24
50 #define __HYPERVISOR_set_segment_base 25 /* x86/64 only */
51 #define __HYPERVISOR_mmuext_op 26
52 #define __HYPERVISOR_acm_op 27
53 #define __HYPERVISOR_nmi_op 28
54 #define __HYPERVISOR_sched_op 29
55 #define __HYPERVISOR_callback_op 30
56 #define __HYPERVISOR_xenoprof_op 31
57 #define __HYPERVISOR_event_channel_op 32
58 #define __HYPERVISOR_physdev_op 33
59 #define __HYPERVISOR_hvm_op 34
60 #define __HYPERVISOR_tmem_op 38
61 
62 /* Architecture-specific hypercall definitions. */
63 #define __HYPERVISOR_arch_0 48
64 #define __HYPERVISOR_arch_1 49
65 #define __HYPERVISOR_arch_2 50
66 #define __HYPERVISOR_arch_3 51
67 #define __HYPERVISOR_arch_4 52
68 #define __HYPERVISOR_arch_5 53
69 #define __HYPERVISOR_arch_6 54
70 #define __HYPERVISOR_arch_7 55
71 
72 /*
73  * VIRTUAL INTERRUPTS
74  *
75  * Virtual interrupts that a guest OS may receive from Xen.
76  */
77 #define VIRQ_TIMER 0 /* Timebase update, and/or requested timeout. */
78 #define VIRQ_DEBUG 1 /* Request guest to dump debug info. */
79 #define VIRQ_CONSOLE 2 /* (DOM0) Bytes received on emergency console. */
80 #define VIRQ_DOM_EXC 3 /* (DOM0) Exceptional event for some domain. */
81 #define VIRQ_DEBUGGER 6 /* (DOM0) A domain has paused for debugging. */
82 #define VIRQ_PCPU_STATE 9 /* (DOM0) PCPU state changed */
83 
84 /* Architecture-specific VIRQ definitions. */
85 #define VIRQ_ARCH_0 16
86 #define VIRQ_ARCH_1 17
87 #define VIRQ_ARCH_2 18
88 #define VIRQ_ARCH_3 19
89 #define VIRQ_ARCH_4 20
90 #define VIRQ_ARCH_5 21
91 #define VIRQ_ARCH_6 22
92 #define VIRQ_ARCH_7 23
93 
94 #define NR_VIRQS 24
95 /*
96  * MMU-UPDATE REQUESTS
97  *
98  * HYPERVISOR_mmu_update() accepts a list of (ptr, val) pairs.
99  * A foreigndom (FD) can be specified (or DOMID_SELF for none).
100  * Where the FD has some effect, it is described below.
101  * ptr[1:0] specifies the appropriate MMU_* command.
102  *
103  * ptr[1:0] == MMU_NORMAL_PT_UPDATE:
104  * Updates an entry in a page table. If updating an L1 table, and the new
105  * table entry is valid/present, the mapped frame must belong to the FD, if
106  * an FD has been specified. If attempting to map an I/O page then the
107  * caller assumes the privilege of the FD.
108  * FD == DOMID_IO: Permit /only/ I/O mappings, at the priv level of the caller.
109  * FD == DOMID_XEN: Map restricted areas of Xen's heap space.
110  * ptr[:2] -- Machine address of the page-table entry to modify.
111  * val -- Value to write.
112  *
113  * ptr[1:0] == MMU_MACHPHYS_UPDATE:
114  * Updates an entry in the machine->pseudo-physical mapping table.
115  * ptr[:2] -- Machine address within the frame whose mapping to modify.
116  * The frame must belong to the FD, if one is specified.
117  * val -- Value to write into the mapping entry.
118  *
119  * ptr[1:0] == MMU_PT_UPDATE_PRESERVE_AD:
120  * As MMU_NORMAL_PT_UPDATE above, but A/D bits currently in the PTE are ORed
121  * with those in @val.
122  */
123 #define MMU_NORMAL_PT_UPDATE 0 /* checked '*ptr = val'. ptr is MA. */
124 #define MMU_MACHPHYS_UPDATE 1 /* ptr = MA of frame to modify entry for */
125 #define MMU_PT_UPDATE_PRESERVE_AD 2 /* atomically: *ptr = val | (*ptr&(A|D)) */
126 
127 /*
128  * MMU EXTENDED OPERATIONS
129  *
130  * HYPERVISOR_mmuext_op() accepts a list of mmuext_op structures.
131  * A foreigndom (FD) can be specified (or DOMID_SELF for none).
132  * Where the FD has some effect, it is described below.
133  *
134  * cmd: MMUEXT_(UN)PIN_*_TABLE
135  * mfn: Machine frame number to be (un)pinned as a p.t. page.
136  * The frame must belong to the FD, if one is specified.
137  *
138  * cmd: MMUEXT_NEW_BASEPTR
139  * mfn: Machine frame number of new page-table base to install in MMU.
140  *
141  * cmd: MMUEXT_NEW_USER_BASEPTR [x86/64 only]
142  * mfn: Machine frame number of new page-table base to install in MMU
143  * when in user space.
144  *
145  * cmd: MMUEXT_TLB_FLUSH_LOCAL
146  * No additional arguments. Flushes local TLB.
147  *
148  * cmd: MMUEXT_INVLPG_LOCAL
149  * linear_addr: Linear address to be flushed from the local TLB.
150  *
151  * cmd: MMUEXT_TLB_FLUSH_MULTI
152  * vcpumask: Pointer to bitmap of VCPUs to be flushed.
153  *
154  * cmd: MMUEXT_INVLPG_MULTI
155  * linear_addr: Linear address to be flushed.
156  * vcpumask: Pointer to bitmap of VCPUs to be flushed.
157  *
158  * cmd: MMUEXT_TLB_FLUSH_ALL
159  * No additional arguments. Flushes all VCPUs' TLBs.
160  *
161  * cmd: MMUEXT_INVLPG_ALL
162  * linear_addr: Linear address to be flushed from all VCPUs' TLBs.
163  *
164  * cmd: MMUEXT_FLUSH_CACHE
165  * No additional arguments. Writes back and flushes cache contents.
166  *
167  * cmd: MMUEXT_SET_LDT
168  * linear_addr: Linear address of LDT base (NB. must be page-aligned).
169  * nr_ents: Number of entries in LDT.
170  */
171 #define MMUEXT_PIN_L1_TABLE 0
172 #define MMUEXT_PIN_L2_TABLE 1
173 #define MMUEXT_PIN_L3_TABLE 2
174 #define MMUEXT_PIN_L4_TABLE 3
175 #define MMUEXT_UNPIN_TABLE 4
176 #define MMUEXT_NEW_BASEPTR 5
177 #define MMUEXT_TLB_FLUSH_LOCAL 6
178 #define MMUEXT_INVLPG_LOCAL 7
179 #define MMUEXT_TLB_FLUSH_MULTI 8
180 #define MMUEXT_INVLPG_MULTI 9
181 #define MMUEXT_TLB_FLUSH_ALL 10
182 #define MMUEXT_INVLPG_ALL 11
183 #define MMUEXT_FLUSH_CACHE 12
184 #define MMUEXT_SET_LDT 13
185 #define MMUEXT_NEW_USER_BASEPTR 15
186 
187 #ifndef __ASSEMBLY__
188 struct mmuext_op {
189  unsigned int cmd;
190  union {
191  /* [UN]PIN_TABLE, NEW_BASEPTR, NEW_USER_BASEPTR */
193  /* INVLPG_LOCAL, INVLPG_ALL, SET_LDT */
194  unsigned long linear_addr;
195  } arg1;
196  union {
197  /* SET_LDT */
198  unsigned int nr_ents;
199  /* TLB_FLUSH_MULTI, INVLPG_MULTI */
200  void *vcpumask;
201  } arg2;
202 };
204 #endif
205 
206 /* These are passed as 'flags' to update_va_mapping. They can be ORed. */
207 /* When specifying UVMF_MULTI, also OR in a pointer to a CPU bitmap. */
208 /* UVMF_LOCAL is merely UVMF_MULTI with a NULL bitmap pointer. */
209 #define UVMF_NONE (0UL<<0) /* No flushing at all. */
210 #define UVMF_TLB_FLUSH (1UL<<0) /* Flush entire TLB(s). */
211 #define UVMF_INVLPG (2UL<<0) /* Flush only one entry. */
212 #define UVMF_FLUSHTYPE_MASK (3UL<<0)
213 #define UVMF_MULTI (0UL<<2) /* Flush subset of TLBs. */
214 #define UVMF_LOCAL (0UL<<2) /* Flush local TLB. */
215 #define UVMF_ALL (1UL<<2) /* Flush all TLBs. */
216 
217 /*
218  * Commands to HYPERVISOR_console_io().
219  */
220 #define CONSOLEIO_write 0
221 #define CONSOLEIO_read 1
222 
223 /*
224  * Commands to HYPERVISOR_vm_assist().
225  */
226 #define VMASST_CMD_enable 0
227 #define VMASST_CMD_disable 1
228 #define VMASST_TYPE_4gb_segments 0
229 #define VMASST_TYPE_4gb_segments_notify 1
230 #define VMASST_TYPE_writable_pagetables 2
231 #define VMASST_TYPE_pae_extended_cr3 3
232 #define MAX_VMASST_TYPE 3
233 
234 #ifndef __ASSEMBLY__
235 
237 
238 /* Domain ids >= DOMID_FIRST_RESERVED cannot be used for ordinary domains. */
239 #define DOMID_FIRST_RESERVED (0x7FF0U)
240 
241 /* DOMID_SELF is used in certain contexts to refer to oneself. */
242 #define DOMID_SELF (0x7FF0U)
243 
244 /*
245  * DOMID_IO is used to restrict page-table updates to mapping I/O memory.
246  * Although no Foreign Domain need be specified to map I/O pages, DOMID_IO
247  * is useful to ensure that no mappings to the OS's own heap are accidentally
248  * installed. (e.g., in Linux this could cause havoc as reference counts
249  * aren't adjusted on the I/O-mapping code path).
250  * This only makes sense in MMUEXT_SET_FOREIGNDOM, but in that context can
251  * be specified by any calling domain.
252  */
253 #define DOMID_IO (0x7FF1U)
254 
255 /*
256  * DOMID_XEN is used to allow privileged domains to map restricted parts of
257  * Xen's heap space (e.g., the machine_to_phys table).
258  * This only makes sense in MMUEXT_SET_FOREIGNDOM, and is only permitted if
259  * the caller is privileged.
260  */
261 #define DOMID_XEN (0x7FF2U)
262 
263 /*
264  * Send an array of these to HYPERVISOR_mmu_update().
265  * NB. The fields are natural pointer/address size for this architecture.
266  */
267 struct mmu_update {
268  uint64_t ptr; /* Machine address of PTE. */
269  uint64_t val; /* New contents of PTE. */
270 };
272 
273 /*
274  * Send an array of these to HYPERVISOR_multicall().
275  * NB. The fields are natural register size for this architecture.
276  */
278  unsigned long op;
279  long result;
280  unsigned long args[6];
281 };
283 
284 /*
285  * Event channel endpoints per domain:
286  * 1024 if a long is 32 bits; 4096 if a long is 64 bits.
287  */
288 #define NR_EVENT_CHANNELS (sizeof(unsigned long) * sizeof(unsigned long) * 64)
289 
291  /*
292  * Updates to the following values are preceded and followed
293  * by an increment of 'version'. The guest can therefore
294  * detect updates by looking for changes to 'version'. If the
295  * least-significant bit of the version number is set then an
296  * update is in progress and the guest must wait to read a
297  * consistent set of values. The correct way to interact with
298  * the version number is similar to Linux's seqlock: see the
299  * implementations of read_seqbegin/read_seqretry.
300  */
303  uint64_t tsc_timestamp; /* TSC at last update of time vals. */
304  uint64_t system_time; /* Time, in nanosecs, since boot. */
305  /*
306  * Current system time:
307  * system_time + ((tsc - tsc_timestamp) << tsc_shift) * tsc_to_system_mul
308  * CPU frequency (Hz):
309  * ((10^9 << 32) / tsc_to_system_mul) >> tsc_shift
310  */
314 }; /* 32 bytes */
315 
316 struct vcpu_info {
317  /*
318  * 'evtchn_upcall_pending' is written non-zero by Xen to indicate
319  * a pending notification for a particular VCPU. It is then cleared
320  * by the guest OS /before/ checking for pending work, thus avoiding
321  * a set-and-check race. Note that the mask is only accessed by Xen
322  * on the CPU that is currently hosting the VCPU. This means that the
323  * pending and mask flags can be updated by the guest without special
324  * synchronisation (i.e., no need for the x86 LOCK prefix).
325  * This may seem suboptimal because if the pending flag is set by
326  * a different CPU then an IPI may be scheduled even when the mask
327  * is set. However, note:
328  * 1. The task of 'interrupt holdoff' is covered by the per-event-
329  * channel mask bits. A 'noisy' event that is continually being
330  * triggered can be masked at source at this very precise
331  * granularity.
332  * 2. The main purpose of the per-VCPU mask is therefore to restrict
333  * reentrant execution: whether for concurrency control, or to
334  * prevent unbounded stack usage. Whatever the purpose, we expect
335  * that the mask will be asserted only for short periods at a time,
336  * and so the likelihood of a 'spurious' IPI is suitably small.
337  * The mask is read before making an event upcall to the guest: a
338  * non-zero mask therefore guarantees that the VCPU will not receive
339  * an upcall activation. The mask is cleared when the VCPU requests
340  * to block: this avoids wakeup-waiting races.
341  */
344  unsigned long evtchn_pending_sel;
347 }; /* 64 bytes (x86) */
348 
349 /*
350  * Xen/kernel shared data -- pointer provided in start_info.
351  * NB. We expect that this struct is smaller than a page.
352  */
353 struct shared_info {
355 
356  /*
357  * A domain can create "event channels" on which it can send and receive
358  * asynchronous event notifications. There are three classes of event that
359  * are delivered by this mechanism:
360  * 1. Bi-directional inter- and intra-domain connections. Domains must
361  * arrange out-of-band to set up a connection (usually by allocating
362  * an unbound 'listener' port and avertising that via a storage service
363  * such as xenstore).
364  * 2. Physical interrupts. A domain with suitable hardware-access
365  * privileges can bind an event-channel port to a physical interrupt
366  * source.
367  * 3. Virtual interrupts ('events'). A domain can bind an event-channel
368  * port to a virtual interrupt source, such as the virtual-timer
369  * device or the emergency console.
370  *
371  * Event channels are addressed by a "port index". Each channel is
372  * associated with two bits of information:
373  * 1. PENDING -- notifies the domain that there is a pending notification
374  * to be processed. This bit is cleared by the guest.
375  * 2. MASK -- if this bit is clear then a 0->1 transition of PENDING
376  * will cause an asynchronous upcall to be scheduled. This bit is only
377  * updated by the guest. It is read-only within Xen. If a channel
378  * becomes pending while the channel is masked then the 'edge' is lost
379  * (i.e., when the channel is unmasked, the guest must manually handle
380  * pending notifications as no upcall will be scheduled by Xen).
381  *
382  * To expedite scanning of pending notifications, any 0->1 pending
383  * transition on an unmasked channel causes a corresponding bit in a
384  * per-vcpu selector word to be set. Each bit in the selector covers a
385  * 'C long' in the PENDING bitfield array.
386  */
387  unsigned long evtchn_pending[sizeof(unsigned long) * 8];
388  unsigned long evtchn_mask[sizeof(unsigned long) * 8];
389 
390  /*
391  * Wallclock time: updated only by control software. Guests should base
392  * their gettimeofday() syscall on this wallclock-base value.
393  */
395 
397 
398 };
399 
400 /*
401  * Start-of-day memory layout for the initial domain (DOM0):
402  * 1. The domain is started within contiguous virtual-memory region.
403  * 2. The contiguous region begins and ends on an aligned 4MB boundary.
404  * 3. The region start corresponds to the load address of the OS image.
405  * If the load address is not 4MB aligned then the address is rounded down.
406  * 4. This the order of bootstrap elements in the initial virtual region:
407  * a. relocated kernel image
408  * b. initial ram disk [mod_start, mod_len]
409  * c. list of allocated page frames [mfn_list, nr_pages]
410  * d. start_info_t structure [register ESI (x86)]
411  * e. bootstrap page tables [pt_base, CR3 (x86)]
412  * f. bootstrap stack [register ESP (x86)]
413  * 5. Bootstrap elements are packed together, but each is 4kB-aligned.
414  * 6. The initial ram disk may be omitted.
415  * 7. The list of page frames forms a contiguous 'pseudo-physical' memory
416  * layout for the domain. In particular, the bootstrap virtual-memory
417  * region is a 1:1 mapping to the first section of the pseudo-physical map.
418  * 8. All bootstrap elements are mapped read-writable for the guest OS. The
419  * only exception is the bootstrap page table, which is mapped read-only.
420  * 9. There is guaranteed to be at least 512kB padding after the final
421  * bootstrap element. If necessary, the bootstrap virtual region is
422  * extended by an extra 4MB to ensure this.
423  */
424 
425 #define MAX_GUEST_CMDLINE 1024
426 struct start_info {
427  /* THE FOLLOWING ARE FILLED IN BOTH ON INITIAL BOOT AND ON RESUME. */
428  char magic[32]; /* "xen-<version>-<platform>". */
429  unsigned long nr_pages; /* Total pages allocated to this domain. */
430  unsigned long shared_info; /* MACHINE address of shared info struct. */
431  uint32_t flags; /* SIF_xxx flags. */
432  xen_pfn_t store_mfn; /* MACHINE page number of shared page. */
433  uint32_t store_evtchn; /* Event channel for store communication. */
434  union {
435  struct {
436  xen_pfn_t mfn; /* MACHINE page number of console page. */
437  uint32_t evtchn; /* Event channel for console page. */
438  } domU;
439  struct {
440  uint32_t info_off; /* Offset of console_info struct. */
441  uint32_t info_size; /* Size of console_info struct from start.*/
442  } dom0;
443  } console;
444  /* THE FOLLOWING ARE ONLY FILLED IN ON INITIAL BOOT (NOT RESUME). */
445  unsigned long pt_base; /* VIRTUAL address of page directory. */
446  unsigned long nr_pt_frames; /* Number of bootstrap p.t. frames. */
447  unsigned long mfn_list; /* VIRTUAL address of page-frame list. */
448  unsigned long mod_start; /* VIRTUAL address of pre-loaded module. */
449  unsigned long mod_len; /* Size (bytes) of pre-loaded module. */
451 };
452 
455 #define XEN_VGATYPE_TEXT_MODE_3 0x03
456 #define XEN_VGATYPE_VESA_LFB 0x23
457 #define XEN_VGATYPE_EFI_LFB 0x70
458 
459  union {
460  struct {
461  /* Font height, in pixels. */
463  /* Cursor location (column, row). */
465  /* Number of rows and columns (dimensions in characters). */
467  } text_mode_3;
468 
469  struct {
470  /* Width and height, in pixels. */
472  /* Bytes per scan line. */
474  /* Bits per pixel. */
476  /* LFB physical address, and size (in units of 64kB). */
479  /* RGB mask offsets and sizes, as defined by VBE 1.2+ */
484 
485  /* VESA capabilities (offset 0xa, VESA command 0x4f00). */
487  /* Mode attributes (offset 0x0, VESA command 0x4f01). */
489  } vesa_lfb;
490  } u;
491 };
492 
493 /* These flags are passed in the 'flags' field of start_info_t. */
494 #define SIF_PRIVILEGED (1<<0) /* Is the domain privileged? */
495 #define SIF_INITDOMAIN (1<<1) /* Is this the initial control domain? */
496 #define SIF_PM_MASK (0xFF<<8) /* reserve 1 byte for xen-pm options */
497 
499 
501 
502 /* Turn a plain number into a C unsigned long constant. */
503 #define __mk_unsigned_long(x) x ## UL
504 #define mk_unsigned_long(x) __mk_unsigned_long(x)
505 
506 #define TMEM_SPEC_VERSION 1
507 
508 struct tmem_op {
511  union {
512  struct { /* for cmd == TMEM_NEW_POOL */
515  } new;
516  struct {
522  GUEST_HANDLE(void) gmfn; /* guest machine page frame */
523  } gen;
524  } u;
525 };
526 
528 
529 #else /* __ASSEMBLY__ */
530 
531 /* In assembly code we cannot use C numeric constant suffixes. */
532 #define mk_unsigned_long(x) x
533 
534 #endif /* !__ASSEMBLY__ */
535 
536 #endif /* __XEN_PUBLIC_XEN_H__ */