1 /******************************************************************************
2  * vm_event.h
3  *
4  * Memory event common structures.
5  *
6  * Copyright (c) 2009 by Citrix Systems, Inc. (Patrick Colp)
7  *
8  * Permission is hereby granted, free of charge, to any person obtaining a copy
9  * of this software and associated documentation files (the "Software"), to
10  * deal in the Software without restriction, including without limitation the
11  * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
12  * sell copies of the Software, and to permit persons to whom the Software is
13  * furnished to do so, subject to the following conditions:
14  *
15  * The above copyright notice and this permission notice shall be included in
16  * all copies or substantial portions of the Software.
17  *
18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
19  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
20  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
21  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
22  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
23  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
24  * DEALINGS IN THE SOFTWARE.
25  */
26 
27 #ifndef _XEN_PUBLIC_VM_EVENT_H
28 #define _XEN_PUBLIC_VM_EVENT_H
29 
30 #include "xen.h"
31 
32 #define VM_EVENT_INTERFACE_VERSION 0x00000006
33 
34 #if defined(__XEN__) || defined(__XEN_TOOLS__)
35 
36 #include "io/ring.h"
37 
38 /*
39  * Memory event flags
40  */
41 
42 /*
43  * VCPU_PAUSED in a request signals that the vCPU triggering the event has been
44  *  paused
45  * VCPU_PAUSED in a response signals to unpause the vCPU
46  */
47 #define VM_EVENT_FLAG_VCPU_PAUSED        (1 << 0)
48 /* Flags to aid debugging vm_event */
49 #define VM_EVENT_FLAG_FOREIGN            (1 << 1)
50 /*
51  * The following flags can be set in response to a mem_access event.
52  *
53  * Emulate the fault-causing instruction (if set in the event response flags).
54  * This will allow the guest to continue execution without lifting the page
55  * access restrictions.
56  */
57 #define VM_EVENT_FLAG_EMULATE            (1 << 2)
58 /*
59  * Same as VM_EVENT_FLAG_EMULATE, but with write operations or operations
60  * potentially having side effects (like memory mapped or port I/O) disabled.
61  */
62 #define VM_EVENT_FLAG_EMULATE_NOWRITE    (1 << 3)
63 /*
64  * Toggle singlestepping on vm_event response.
65  * Requires the vCPU to be paused already (synchronous events only).
66  */
67 #define VM_EVENT_FLAG_TOGGLE_SINGLESTEP  (1 << 4)
68 /*
69  * Data is being sent back to the hypervisor in the event response, to be
70  * returned by the read function when emulating an instruction.
71  * This flag is only useful when combined with VM_EVENT_FLAG_EMULATE
72  * and takes precedence if combined with VM_EVENT_FLAG_EMULATE_NOWRITE
73  * (i.e. if both VM_EVENT_FLAG_EMULATE_NOWRITE and
74  * VM_EVENT_FLAG_SET_EMUL_READ_DATA are set, only the latter will be honored).
75  */
76 #define VM_EVENT_FLAG_SET_EMUL_READ_DATA (1 << 5)
77 /*
78  * Deny completion of the operation that triggered the event.
79  * Currently only useful for MSR and control-register write events.
80  * Requires the vCPU to be paused already (synchronous events only).
81  */
82 #define VM_EVENT_FLAG_DENY               (1 << 6)
83 /*
84  * This flag can be set in a request or a response
85  *
86  * On a request, indicates that the event occurred in the alternate p2m
87  * specified by the altp2m_idx request field.
88  *
89  * On a response, indicates that the VCPU should resume in the alternate p2m
90  * specified by the altp2m_idx response field if possible.
91  */
92 #define VM_EVENT_FLAG_ALTERNATE_P2M      (1 << 7)
93 /*
94  * Set the vCPU registers to the values in the  vm_event response.
95  * At the moment x86-only, applies to EAX-EDX, ESP, EBP, ESI, EDI, R8-R15,
96  * EFLAGS, and EIP.
97  * Requires the vCPU to be paused already (synchronous events only).
98  */
99 #define VM_EVENT_FLAG_SET_REGISTERS      (1 << 8)
100 /*
101  * Instruction cache is being sent back to the hypervisor in the event response
102  * to be used by the emulator. This flag is only useful when combined with
103  * VM_EVENT_FLAG_EMULATE and does not take presedence if combined with
104  * VM_EVENT_FLAG_EMULATE_NOWRITE or VM_EVENT_FLAG_SET_EMUL_READ_DATA, (i.e.
105  * if any of those flags are set, only those will be honored).
106  */
107 #define VM_EVENT_FLAG_SET_EMUL_INSN_DATA (1 << 9)
108 /*
109  * Have a one-shot VM_EVENT_REASON_INTERRUPT event sent for the first
110  * interrupt pending after resuming the VCPU.
111  */
112 #define VM_EVENT_FLAG_GET_NEXT_INTERRUPT (1 << 10)
113 /*
114  * Execute fast singlestepping on vm_event response.
115  * Requires the vCPU to be paused already (synchronous events only).
116  *
117  * On a response requires setting the  p2midx field of fast_singlestep to which
118  * Xen will switch the vCPU to on the occurance of the first singlestep, after
119  * which singlestep gets automatically disabled.
120  */
121 #define VM_EVENT_FLAG_FAST_SINGLESTEP    (1 << 11)
122 
123 /*
124  * Reasons for the vm event request
125  */
126 
127 /* Default case */
128 #define VM_EVENT_REASON_UNKNOWN                 0
129 /* Memory access violation */
130 #define VM_EVENT_REASON_MEM_ACCESS              1
131 /* Memory sharing event */
132 #define VM_EVENT_REASON_MEM_SHARING             2
133 /* Memory paging event */
134 #define VM_EVENT_REASON_MEM_PAGING              3
135 /* A control register was updated */
136 #define VM_EVENT_REASON_WRITE_CTRLREG           4
137 /* An MSR was updated. */
138 #define VM_EVENT_REASON_MOV_TO_MSR              5
139 /* Debug operation executed (e.g. int3) */
140 #define VM_EVENT_REASON_SOFTWARE_BREAKPOINT     6
141 /* Single-step (e.g. MTF) */
142 #define VM_EVENT_REASON_SINGLESTEP              7
143 /* An event has been requested via HVMOP_guest_request_vm_event. */
144 #define VM_EVENT_REASON_GUEST_REQUEST           8
145 /* A debug exception was caught */
146 #define VM_EVENT_REASON_DEBUG_EXCEPTION         9
147 /* CPUID executed */
148 #define VM_EVENT_REASON_CPUID                   10
149 /*
150  * Privileged call executed (e.g. SMC).
151  * Note: event may be generated even if SMC condition check fails on some CPUs.
152  *       As this behavior is CPU-specific, users are advised to not rely on it.
153  *       These kinds of events will be filtered out in future versions.
154  */
155 #define VM_EVENT_REASON_PRIVILEGED_CALL         11
156 /* An interrupt has been delivered. */
157 #define VM_EVENT_REASON_INTERRUPT               12
158 /* A descriptor table register was accessed. */
159 #define VM_EVENT_REASON_DESCRIPTOR_ACCESS       13
160 /* Current instruction is not implemented by the emulator */
161 #define VM_EVENT_REASON_EMUL_UNIMPLEMENTED      14
162 
163 /* Supported values for the vm_event_write_ctrlreg index. */
164 #define VM_EVENT_X86_CR0    0
165 #define VM_EVENT_X86_CR3    1
166 #define VM_EVENT_X86_CR4    2
167 #define VM_EVENT_X86_XCR0   3
168 
169 /* The limit field is right-shifted by 12 bits if .ar.g is set. */
170 struct vm_event_x86_selector_reg {
171     uint32_t limit  :    20;
172     uint32_t ar     :    12;
173 };
174 
175 /*
176  * Using custom vCPU structs (i.e. not hvm_hw_cpu) for both x86 and ARM
177  * so as to not fill the vm_event ring buffer too quickly.
178  */
179 struct vm_event_regs_x86 {
180     uint64_t rax;
181     uint64_t rcx;
182     uint64_t rdx;
183     uint64_t rbx;
184     uint64_t rsp;
185     uint64_t rbp;
186     uint64_t rsi;
187     uint64_t rdi;
188     uint64_t r8;
189     uint64_t r9;
190     uint64_t r10;
191     uint64_t r11;
192     uint64_t r12;
193     uint64_t r13;
194     uint64_t r14;
195     uint64_t r15;
196     uint64_t rflags;
197     uint64_t dr6;
198     uint64_t dr7;
199     uint64_t rip;
200     uint64_t cr0;
201     uint64_t cr2;
202     uint64_t cr3;
203     uint64_t cr4;
204     uint64_t sysenter_cs;
205     uint64_t sysenter_esp;
206     uint64_t sysenter_eip;
207     uint64_t msr_efer;
208     uint64_t msr_star;
209     uint64_t msr_lstar;
210     uint64_t gdtr_base;
211     uint32_t cs_base;
212     uint32_t ss_base;
213     uint32_t ds_base;
214     uint32_t es_base;
215     uint64_t fs_base;
216     uint64_t gs_base;
217     struct vm_event_x86_selector_reg cs;
218     struct vm_event_x86_selector_reg ss;
219     struct vm_event_x86_selector_reg ds;
220     struct vm_event_x86_selector_reg es;
221     struct vm_event_x86_selector_reg fs;
222     struct vm_event_x86_selector_reg gs;
223     uint64_t shadow_gs;
224     uint16_t gdtr_limit;
225     uint16_t cs_sel;
226     uint16_t ss_sel;
227     uint16_t ds_sel;
228     uint16_t es_sel;
229     uint16_t fs_sel;
230     uint16_t gs_sel;
231     uint16_t _pad;
232 };
233 
234 /*
235  * Only the register 'pc' can be set on a vm_event response using the
236  * VM_EVENT_FLAG_SET_REGISTERS flag.
237  */
238 struct vm_event_regs_arm {
239     uint64_t ttbr0;
240     uint64_t ttbr1;
241     uint64_t ttbcr;
242     uint64_t pc;
243     uint32_t cpsr;
244     uint32_t _pad;
245 };
246 
247 /*
248  * mem_access flag definitions
249  *
250  * These flags are set only as part of a mem_event request.
251  *
252  * R/W/X: Defines the type of violation that has triggered the event
253  *        Multiple types can be set in a single violation!
254  * GLA_VALID: If the gla field holds a guest VA associated with the event
255  * FAULT_WITH_GLA: If the violation was triggered by accessing gla
256  * FAULT_IN_GPT: If the violation was triggered during translating gla
257  */
258 #define MEM_ACCESS_R                (1 << 0)
259 #define MEM_ACCESS_W                (1 << 1)
260 #define MEM_ACCESS_X                (1 << 2)
261 #define MEM_ACCESS_RWX              (MEM_ACCESS_R | MEM_ACCESS_W | MEM_ACCESS_X)
262 #define MEM_ACCESS_RW               (MEM_ACCESS_R | MEM_ACCESS_W)
263 #define MEM_ACCESS_RX               (MEM_ACCESS_R | MEM_ACCESS_X)
264 #define MEM_ACCESS_WX               (MEM_ACCESS_W | MEM_ACCESS_X)
265 #define MEM_ACCESS_GLA_VALID        (1 << 3)
266 #define MEM_ACCESS_FAULT_WITH_GLA   (1 << 4)
267 #define MEM_ACCESS_FAULT_IN_GPT     (1 << 5)
268 
269 struct vm_event_mem_access {
270     uint64_t gfn;
271     uint64_t offset;
272     uint64_t gla;   /* if flags has MEM_ACCESS_GLA_VALID set */
273     uint32_t flags; /* MEM_ACCESS_* */
274     uint32_t _pad;
275 };
276 
277 struct vm_event_write_ctrlreg {
278     uint32_t index;
279     uint32_t _pad;
280     uint64_t new_value;
281     uint64_t old_value;
282 };
283 
284 struct vm_event_singlestep {
285     uint64_t gfn;
286 };
287 
288 struct vm_event_fast_singlestep {
289     uint16_t p2midx;
290 };
291 
292 struct vm_event_debug {
293     uint64_t gfn;
294     uint64_t pending_dbg; /* Behaves like the VT-x PENDING_DBG field. */
295     uint32_t insn_length;
296     uint8_t type;        /* HVMOP_TRAP_* */
297     uint8_t _pad[3];
298 };
299 
300 struct vm_event_mov_to_msr {
301     uint64_t msr;
302     uint64_t new_value;
303     uint64_t old_value;
304 };
305 
306 #define VM_EVENT_DESC_IDTR           1
307 #define VM_EVENT_DESC_GDTR           2
308 #define VM_EVENT_DESC_LDTR           3
309 #define VM_EVENT_DESC_TR             4
310 
311 struct vm_event_desc_access {
312     union {
313         struct {
314             uint32_t instr_info;         /* VMX: VMCS Instruction-Information */
315             uint32_t _pad1;
316             uint64_t exit_qualification; /* VMX: VMCS Exit Qualification */
317         } vmx;
318     } arch;
319     uint8_t descriptor;                  /* VM_EVENT_DESC_* */
320     uint8_t is_write;
321     uint8_t _pad[6];
322 };
323 
324 struct vm_event_cpuid {
325     uint32_t insn_length;
326     uint32_t leaf;
327     uint32_t subleaf;
328     uint32_t _pad;
329 };
330 
331 struct vm_event_interrupt_x86 {
332     uint32_t vector;
333     uint32_t type;
334     uint32_t error_code;
335     uint32_t _pad;
336     uint64_t cr2;
337 };
338 
339 #define MEM_PAGING_DROP_PAGE       (1 << 0)
340 #define MEM_PAGING_EVICT_FAIL      (1 << 1)
341 
342 struct vm_event_paging {
343     uint64_t gfn;
344     uint32_t p2mt;
345     uint32_t flags;
346 };
347 
348 struct vm_event_sharing {
349     uint64_t gfn;
350     uint32_t p2mt;
351     uint32_t _pad;
352 };
353 
354 struct vm_event_emul_read_data {
355     uint32_t size;
356     /* The struct is used in a union with vm_event_regs_x86. */
357     uint8_t  data[sizeof(struct vm_event_regs_x86) - sizeof(uint32_t)];
358 };
359 
360 struct vm_event_emul_insn_data {
361     uint8_t data[16]; /* Has to be completely filled */
362 };
363 
364 typedef struct vm_event_st {
365     uint32_t version;   /* VM_EVENT_INTERFACE_VERSION */
366     uint32_t flags;     /* VM_EVENT_FLAG_* */
367     uint32_t reason;    /* VM_EVENT_REASON_* */
368     uint32_t vcpu_id;
369     uint16_t altp2m_idx; /* may be used during request and response */
370     uint16_t _pad[3];
371 
372     union {
373         struct vm_event_paging                mem_paging;
374         struct vm_event_sharing               mem_sharing;
375         struct vm_event_mem_access            mem_access;
376         struct vm_event_write_ctrlreg         write_ctrlreg;
377         struct vm_event_mov_to_msr            mov_to_msr;
378         struct vm_event_desc_access           desc_access;
379         struct vm_event_singlestep            singlestep;
380         struct vm_event_fast_singlestep       fast_singlestep;
381         struct vm_event_debug                 software_breakpoint;
382         struct vm_event_debug                 debug_exception;
383         struct vm_event_cpuid                 cpuid;
384         union {
385             struct vm_event_interrupt_x86     x86;
386         } interrupt;
387     } u;
388 
389     union {
390         union {
391             struct vm_event_regs_x86 x86;
392             struct vm_event_regs_arm arm;
393         } regs;
394 
395         union {
396             struct vm_event_emul_read_data read;
397             struct vm_event_emul_insn_data insn;
398         } emul;
399     } data;
400 } vm_event_request_t, vm_event_response_t;
401 
402 DEFINE_RING_TYPES(vm_event, vm_event_request_t, vm_event_response_t);
403 
404 #endif /* defined(__XEN__) || defined(__XEN_TOOLS__) */
405 #endif /* _XEN_PUBLIC_VM_EVENT_H */
406 
407 /*
408  * Local variables:
409  * mode: C
410  * c-file-style: "BSD"
411  * c-basic-offset: 4
412  * tab-width: 4
413  * indent-tabs-mode: nil
414  * End:
415  */
416