xref: /openbmc/linux/include/xen/interface/xen.h (revision 9ac8d3fb)
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 #include <asm/pvclock-abi.h>
14 
15 /*
16  * XEN "SYSTEM CALLS" (a.k.a. HYPERCALLS).
17  */
18 
19 /*
20  * x86_32: EAX = vector; EBX, ECX, EDX, ESI, EDI = args 1, 2, 3, 4, 5.
21  *         EAX = return value
22  *         (argument registers may be clobbered on return)
23  * x86_64: RAX = vector; RDI, RSI, RDX, R10, R8, R9 = args 1, 2, 3, 4, 5, 6.
24  *         RAX = return value
25  *         (argument registers not clobbered on return; RCX, R11 are)
26  */
27 #define __HYPERVISOR_set_trap_table        0
28 #define __HYPERVISOR_mmu_update            1
29 #define __HYPERVISOR_set_gdt               2
30 #define __HYPERVISOR_stack_switch          3
31 #define __HYPERVISOR_set_callbacks         4
32 #define __HYPERVISOR_fpu_taskswitch        5
33 #define __HYPERVISOR_sched_op              6
34 #define __HYPERVISOR_dom0_op               7
35 #define __HYPERVISOR_set_debugreg          8
36 #define __HYPERVISOR_get_debugreg          9
37 #define __HYPERVISOR_update_descriptor    10
38 #define __HYPERVISOR_memory_op            12
39 #define __HYPERVISOR_multicall            13
40 #define __HYPERVISOR_update_va_mapping    14
41 #define __HYPERVISOR_set_timer_op         15
42 #define __HYPERVISOR_event_channel_op_compat 16
43 #define __HYPERVISOR_xen_version          17
44 #define __HYPERVISOR_console_io           18
45 #define __HYPERVISOR_physdev_op_compat    19
46 #define __HYPERVISOR_grant_table_op       20
47 #define __HYPERVISOR_vm_assist            21
48 #define __HYPERVISOR_update_va_mapping_otherdomain 22
49 #define __HYPERVISOR_iret                 23 /* x86 only */
50 #define __HYPERVISOR_vcpu_op              24
51 #define __HYPERVISOR_set_segment_base     25 /* x86/64 only */
52 #define __HYPERVISOR_mmuext_op            26
53 #define __HYPERVISOR_acm_op               27
54 #define __HYPERVISOR_nmi_op               28
55 #define __HYPERVISOR_sched_op_new         29
56 #define __HYPERVISOR_callback_op          30
57 #define __HYPERVISOR_xenoprof_op          31
58 #define __HYPERVISOR_event_channel_op     32
59 #define __HYPERVISOR_physdev_op           33
60 #define __HYPERVISOR_hvm_op               34
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 
83 /* Architecture-specific VIRQ definitions. */
84 #define VIRQ_ARCH_0    16
85 #define VIRQ_ARCH_1    17
86 #define VIRQ_ARCH_2    18
87 #define VIRQ_ARCH_3    19
88 #define VIRQ_ARCH_4    20
89 #define VIRQ_ARCH_5    21
90 #define VIRQ_ARCH_6    22
91 #define VIRQ_ARCH_7    23
92 
93 #define NR_VIRQS       24
94 /*
95  * MMU-UPDATE REQUESTS
96  *
97  * HYPERVISOR_mmu_update() accepts a list of (ptr, val) pairs.
98  * A foreigndom (FD) can be specified (or DOMID_SELF for none).
99  * Where the FD has some effect, it is described below.
100  * ptr[1:0] specifies the appropriate MMU_* command.
101  *
102  * ptr[1:0] == MMU_NORMAL_PT_UPDATE:
103  * Updates an entry in a page table. If updating an L1 table, and the new
104  * table entry is valid/present, the mapped frame must belong to the FD, if
105  * an FD has been specified. If attempting to map an I/O page then the
106  * caller assumes the privilege of the FD.
107  * FD == DOMID_IO: Permit /only/ I/O mappings, at the priv level of the caller.
108  * FD == DOMID_XEN: Map restricted areas of Xen's heap space.
109  * ptr[:2]  -- Machine address of the page-table entry to modify.
110  * val      -- Value to write.
111  *
112  * ptr[1:0] == MMU_MACHPHYS_UPDATE:
113  * Updates an entry in the machine->pseudo-physical mapping table.
114  * ptr[:2]  -- Machine address within the frame whose mapping to modify.
115  *             The frame must belong to the FD, if one is specified.
116  * val      -- Value to write into the mapping entry.
117  *
118  * ptr[1:0] == MMU_PT_UPDATE_PRESERVE_AD:
119  * As MMU_NORMAL_PT_UPDATE above, but A/D bits currently in the PTE are ORed
120  * with those in @val.
121  */
122 #define MMU_NORMAL_PT_UPDATE      0 /* checked '*ptr = val'. ptr is MA.       */
123 #define MMU_MACHPHYS_UPDATE       1 /* ptr = MA of frame to modify entry for  */
124 #define MMU_PT_UPDATE_PRESERVE_AD 2 /* atomically: *ptr = val | (*ptr&(A|D)) */
125 
126 /*
127  * MMU EXTENDED OPERATIONS
128  *
129  * HYPERVISOR_mmuext_op() accepts a list of mmuext_op structures.
130  * A foreigndom (FD) can be specified (or DOMID_SELF for none).
131  * Where the FD has some effect, it is described below.
132  *
133  * cmd: MMUEXT_(UN)PIN_*_TABLE
134  * mfn: Machine frame number to be (un)pinned as a p.t. page.
135  *      The frame must belong to the FD, if one is specified.
136  *
137  * cmd: MMUEXT_NEW_BASEPTR
138  * mfn: Machine frame number of new page-table base to install in MMU.
139  *
140  * cmd: MMUEXT_NEW_USER_BASEPTR [x86/64 only]
141  * mfn: Machine frame number of new page-table base to install in MMU
142  *      when in user space.
143  *
144  * cmd: MMUEXT_TLB_FLUSH_LOCAL
145  * No additional arguments. Flushes local TLB.
146  *
147  * cmd: MMUEXT_INVLPG_LOCAL
148  * linear_addr: Linear address to be flushed from the local TLB.
149  *
150  * cmd: MMUEXT_TLB_FLUSH_MULTI
151  * vcpumask: Pointer to bitmap of VCPUs to be flushed.
152  *
153  * cmd: MMUEXT_INVLPG_MULTI
154  * linear_addr: Linear address to be flushed.
155  * vcpumask: Pointer to bitmap of VCPUs to be flushed.
156  *
157  * cmd: MMUEXT_TLB_FLUSH_ALL
158  * No additional arguments. Flushes all VCPUs' TLBs.
159  *
160  * cmd: MMUEXT_INVLPG_ALL
161  * linear_addr: Linear address to be flushed from all VCPUs' TLBs.
162  *
163  * cmd: MMUEXT_FLUSH_CACHE
164  * No additional arguments. Writes back and flushes cache contents.
165  *
166  * cmd: MMUEXT_SET_LDT
167  * linear_addr: Linear address of LDT base (NB. must be page-aligned).
168  * nr_ents: Number of entries in LDT.
169  */
170 #define MMUEXT_PIN_L1_TABLE      0
171 #define MMUEXT_PIN_L2_TABLE      1
172 #define MMUEXT_PIN_L3_TABLE      2
173 #define MMUEXT_PIN_L4_TABLE      3
174 #define MMUEXT_UNPIN_TABLE       4
175 #define MMUEXT_NEW_BASEPTR       5
176 #define MMUEXT_TLB_FLUSH_LOCAL   6
177 #define MMUEXT_INVLPG_LOCAL      7
178 #define MMUEXT_TLB_FLUSH_MULTI   8
179 #define MMUEXT_INVLPG_MULTI      9
180 #define MMUEXT_TLB_FLUSH_ALL    10
181 #define MMUEXT_INVLPG_ALL       11
182 #define MMUEXT_FLUSH_CACHE      12
183 #define MMUEXT_SET_LDT          13
184 #define MMUEXT_NEW_USER_BASEPTR 15
185 
186 #ifndef __ASSEMBLY__
187 struct mmuext_op {
188 	unsigned int cmd;
189 	union {
190 		/* [UN]PIN_TABLE, NEW_BASEPTR, NEW_USER_BASEPTR */
191 		unsigned long mfn;
192 		/* INVLPG_LOCAL, INVLPG_ALL, SET_LDT */
193 		unsigned long linear_addr;
194 	} arg1;
195 	union {
196 		/* SET_LDT */
197 		unsigned int nr_ents;
198 		/* TLB_FLUSH_MULTI, INVLPG_MULTI */
199 		void *vcpumask;
200 	} arg2;
201 };
202 DEFINE_GUEST_HANDLE_STRUCT(mmuext_op);
203 #endif
204 
205 /* These are passed as 'flags' to update_va_mapping. They can be ORed. */
206 /* When specifying UVMF_MULTI, also OR in a pointer to a CPU bitmap.   */
207 /* UVMF_LOCAL is merely UVMF_MULTI with a NULL bitmap pointer.         */
208 #define UVMF_NONE               (0UL<<0) /* No flushing at all.   */
209 #define UVMF_TLB_FLUSH          (1UL<<0) /* Flush entire TLB(s).  */
210 #define UVMF_INVLPG             (2UL<<0) /* Flush only one entry. */
211 #define UVMF_FLUSHTYPE_MASK     (3UL<<0)
212 #define UVMF_MULTI              (0UL<<2) /* Flush subset of TLBs. */
213 #define UVMF_LOCAL              (0UL<<2) /* Flush local TLB.      */
214 #define UVMF_ALL                (1UL<<2) /* Flush all TLBs.       */
215 
216 /*
217  * Commands to HYPERVISOR_console_io().
218  */
219 #define CONSOLEIO_write         0
220 #define CONSOLEIO_read          1
221 
222 /*
223  * Commands to HYPERVISOR_vm_assist().
224  */
225 #define VMASST_CMD_enable                0
226 #define VMASST_CMD_disable               1
227 #define VMASST_TYPE_4gb_segments         0
228 #define VMASST_TYPE_4gb_segments_notify  1
229 #define VMASST_TYPE_writable_pagetables  2
230 #define VMASST_TYPE_pae_extended_cr3     3
231 #define MAX_VMASST_TYPE 3
232 
233 #ifndef __ASSEMBLY__
234 
235 typedef uint16_t domid_t;
236 
237 /* Domain ids >= DOMID_FIRST_RESERVED cannot be used for ordinary domains. */
238 #define DOMID_FIRST_RESERVED (0x7FF0U)
239 
240 /* DOMID_SELF is used in certain contexts to refer to oneself. */
241 #define DOMID_SELF (0x7FF0U)
242 
243 /*
244  * DOMID_IO is used to restrict page-table updates to mapping I/O memory.
245  * Although no Foreign Domain need be specified to map I/O pages, DOMID_IO
246  * is useful to ensure that no mappings to the OS's own heap are accidentally
247  * installed. (e.g., in Linux this could cause havoc as reference counts
248  * aren't adjusted on the I/O-mapping code path).
249  * This only makes sense in MMUEXT_SET_FOREIGNDOM, but in that context can
250  * be specified by any calling domain.
251  */
252 #define DOMID_IO   (0x7FF1U)
253 
254 /*
255  * DOMID_XEN is used to allow privileged domains to map restricted parts of
256  * Xen's heap space (e.g., the machine_to_phys table).
257  * This only makes sense in MMUEXT_SET_FOREIGNDOM, and is only permitted if
258  * the caller is privileged.
259  */
260 #define DOMID_XEN  (0x7FF2U)
261 
262 /*
263  * Send an array of these to HYPERVISOR_mmu_update().
264  * NB. The fields are natural pointer/address size for this architecture.
265  */
266 struct mmu_update {
267     uint64_t ptr;       /* Machine address of PTE. */
268     uint64_t val;       /* New contents of PTE.    */
269 };
270 DEFINE_GUEST_HANDLE_STRUCT(mmu_update);
271 
272 /*
273  * Send an array of these to HYPERVISOR_multicall().
274  * NB. The fields are natural register size for this architecture.
275  */
276 struct multicall_entry {
277     unsigned long op;
278     long result;
279     unsigned long args[6];
280 };
281 DEFINE_GUEST_HANDLE_STRUCT(multicall_entry);
282 
283 /*
284  * Event channel endpoints per domain:
285  *  1024 if a long is 32 bits; 4096 if a long is 64 bits.
286  */
287 #define NR_EVENT_CHANNELS (sizeof(unsigned long) * sizeof(unsigned long) * 64)
288 
289 struct vcpu_time_info {
290 	/*
291 	 * Updates to the following values are preceded and followed
292 	 * by an increment of 'version'. The guest can therefore
293 	 * detect updates by looking for changes to 'version'. If the
294 	 * least-significant bit of the version number is set then an
295 	 * update is in progress and the guest must wait to read a
296 	 * consistent set of values.  The correct way to interact with
297 	 * the version number is similar to Linux's seqlock: see the
298 	 * implementations of read_seqbegin/read_seqretry.
299 	 */
300 	uint32_t version;
301 	uint32_t pad0;
302 	uint64_t tsc_timestamp;   /* TSC at last update of time vals.  */
303 	uint64_t system_time;     /* Time, in nanosecs, since boot.    */
304 	/*
305 	 * Current system time:
306 	 *   system_time + ((tsc - tsc_timestamp) << tsc_shift) * tsc_to_system_mul
307 	 * CPU frequency (Hz):
308 	 *   ((10^9 << 32) / tsc_to_system_mul) >> tsc_shift
309 	 */
310 	uint32_t tsc_to_system_mul;
311 	int8_t   tsc_shift;
312 	int8_t   pad1[3];
313 }; /* 32 bytes */
314 
315 struct vcpu_info {
316 	/*
317 	 * 'evtchn_upcall_pending' is written non-zero by Xen to indicate
318 	 * a pending notification for a particular VCPU. It is then cleared
319 	 * by the guest OS /before/ checking for pending work, thus avoiding
320 	 * a set-and-check race. Note that the mask is only accessed by Xen
321 	 * on the CPU that is currently hosting the VCPU. This means that the
322 	 * pending and mask flags can be updated by the guest without special
323 	 * synchronisation (i.e., no need for the x86 LOCK prefix).
324 	 * This may seem suboptimal because if the pending flag is set by
325 	 * a different CPU then an IPI may be scheduled even when the mask
326 	 * is set. However, note:
327 	 *  1. The task of 'interrupt holdoff' is covered by the per-event-
328 	 *     channel mask bits. A 'noisy' event that is continually being
329 	 *     triggered can be masked at source at this very precise
330 	 *     granularity.
331 	 *  2. The main purpose of the per-VCPU mask is therefore to restrict
332 	 *     reentrant execution: whether for concurrency control, or to
333 	 *     prevent unbounded stack usage. Whatever the purpose, we expect
334 	 *     that the mask will be asserted only for short periods at a time,
335 	 *     and so the likelihood of a 'spurious' IPI is suitably small.
336 	 * The mask is read before making an event upcall to the guest: a
337 	 * non-zero mask therefore guarantees that the VCPU will not receive
338 	 * an upcall activation. The mask is cleared when the VCPU requests
339 	 * to block: this avoids wakeup-waiting races.
340 	 */
341 	uint8_t evtchn_upcall_pending;
342 	uint8_t evtchn_upcall_mask;
343 	unsigned long evtchn_pending_sel;
344 	struct arch_vcpu_info arch;
345 	struct pvclock_vcpu_time_info time;
346 }; /* 64 bytes (x86) */
347 
348 /*
349  * Xen/kernel shared data -- pointer provided in start_info.
350  * NB. We expect that this struct is smaller than a page.
351  */
352 struct shared_info {
353 	struct vcpu_info vcpu_info[MAX_VIRT_CPUS];
354 
355 	/*
356 	 * A domain can create "event channels" on which it can send and receive
357 	 * asynchronous event notifications. There are three classes of event that
358 	 * are delivered by this mechanism:
359 	 *  1. Bi-directional inter- and intra-domain connections. Domains must
360 	 *     arrange out-of-band to set up a connection (usually by allocating
361 	 *     an unbound 'listener' port and avertising that via a storage service
362 	 *     such as xenstore).
363 	 *  2. Physical interrupts. A domain with suitable hardware-access
364 	 *     privileges can bind an event-channel port to a physical interrupt
365 	 *     source.
366 	 *  3. Virtual interrupts ('events'). A domain can bind an event-channel
367 	 *     port to a virtual interrupt source, such as the virtual-timer
368 	 *     device or the emergency console.
369 	 *
370 	 * Event channels are addressed by a "port index". Each channel is
371 	 * associated with two bits of information:
372 	 *  1. PENDING -- notifies the domain that there is a pending notification
373 	 *     to be processed. This bit is cleared by the guest.
374 	 *  2. MASK -- if this bit is clear then a 0->1 transition of PENDING
375 	 *     will cause an asynchronous upcall to be scheduled. This bit is only
376 	 *     updated by the guest. It is read-only within Xen. If a channel
377 	 *     becomes pending while the channel is masked then the 'edge' is lost
378 	 *     (i.e., when the channel is unmasked, the guest must manually handle
379 	 *     pending notifications as no upcall will be scheduled by Xen).
380 	 *
381 	 * To expedite scanning of pending notifications, any 0->1 pending
382 	 * transition on an unmasked channel causes a corresponding bit in a
383 	 * per-vcpu selector word to be set. Each bit in the selector covers a
384 	 * 'C long' in the PENDING bitfield array.
385 	 */
386 	unsigned long evtchn_pending[sizeof(unsigned long) * 8];
387 	unsigned long evtchn_mask[sizeof(unsigned long) * 8];
388 
389 	/*
390 	 * Wallclock time: updated only by control software. Guests should base
391 	 * their gettimeofday() syscall on this wallclock-base value.
392 	 */
393 	struct pvclock_wall_clock wc;
394 
395 	struct arch_shared_info arch;
396 
397 };
398 
399 /*
400  * Start-of-day memory layout for the initial domain (DOM0):
401  *  1. The domain is started within contiguous virtual-memory region.
402  *  2. The contiguous region begins and ends on an aligned 4MB boundary.
403  *  3. The region start corresponds to the load address of the OS image.
404  *     If the load address is not 4MB aligned then the address is rounded down.
405  *  4. This the order of bootstrap elements in the initial virtual region:
406  *      a. relocated kernel image
407  *      b. initial ram disk              [mod_start, mod_len]
408  *      c. list of allocated page frames [mfn_list, nr_pages]
409  *      d. start_info_t structure        [register ESI (x86)]
410  *      e. bootstrap page tables         [pt_base, CR3 (x86)]
411  *      f. bootstrap stack               [register ESP (x86)]
412  *  5. Bootstrap elements are packed together, but each is 4kB-aligned.
413  *  6. The initial ram disk may be omitted.
414  *  7. The list of page frames forms a contiguous 'pseudo-physical' memory
415  *     layout for the domain. In particular, the bootstrap virtual-memory
416  *     region is a 1:1 mapping to the first section of the pseudo-physical map.
417  *  8. All bootstrap elements are mapped read-writable for the guest OS. The
418  *     only exception is the bootstrap page table, which is mapped read-only.
419  *  9. There is guaranteed to be at least 512kB padding after the final
420  *     bootstrap element. If necessary, the bootstrap virtual region is
421  *     extended by an extra 4MB to ensure this.
422  */
423 
424 #define MAX_GUEST_CMDLINE 1024
425 struct start_info {
426 	/* THE FOLLOWING ARE FILLED IN BOTH ON INITIAL BOOT AND ON RESUME.    */
427 	char magic[32];             /* "xen-<version>-<platform>".            */
428 	unsigned long nr_pages;     /* Total pages allocated to this domain.  */
429 	unsigned long shared_info;  /* MACHINE address of shared info struct. */
430 	uint32_t flags;             /* SIF_xxx flags.                         */
431 	unsigned long store_mfn;    /* MACHINE page number of shared page.    */
432 	uint32_t store_evtchn;      /* Event channel for store communication. */
433 	union {
434 		struct {
435 			unsigned long mfn;  /* MACHINE page number of console page.   */
436 			uint32_t  evtchn;   /* Event channel for console page.        */
437 		} domU;
438 		struct {
439 			uint32_t info_off;  /* Offset of console_info struct.         */
440 			uint32_t info_size; /* Size of console_info struct from start.*/
441 		} dom0;
442 	} console;
443 	/* THE FOLLOWING ARE ONLY FILLED IN ON INITIAL BOOT (NOT RESUME).     */
444 	unsigned long pt_base;      /* VIRTUAL address of page directory.     */
445 	unsigned long nr_pt_frames; /* Number of bootstrap p.t. frames.       */
446 	unsigned long mfn_list;     /* VIRTUAL address of page-frame list.    */
447 	unsigned long mod_start;    /* VIRTUAL address of pre-loaded module.  */
448 	unsigned long mod_len;      /* Size (bytes) of pre-loaded module.     */
449 	int8_t cmd_line[MAX_GUEST_CMDLINE];
450 };
451 
452 /* These flags are passed in the 'flags' field of start_info_t. */
453 #define SIF_PRIVILEGED    (1<<0)  /* Is the domain privileged? */
454 #define SIF_INITDOMAIN    (1<<1)  /* Is this the initial control domain? */
455 
456 typedef uint64_t cpumap_t;
457 
458 typedef uint8_t xen_domain_handle_t[16];
459 
460 /* Turn a plain number into a C unsigned long constant. */
461 #define __mk_unsigned_long(x) x ## UL
462 #define mk_unsigned_long(x) __mk_unsigned_long(x)
463 
464 #else /* __ASSEMBLY__ */
465 
466 /* In assembly code we cannot use C numeric constant suffixes. */
467 #define mk_unsigned_long(x) x
468 
469 #endif /* !__ASSEMBLY__ */
470 
471 #endif /* __XEN_PUBLIC_XEN_H__ */
472