1 /* Common data structures and functions consumed by hypervisor and toolstack */
2 #ifndef XEN_LIB_X86_CPUID_H
3 #define XEN_LIB_X86_CPUID_H
4 
5 #include <xen/lib/x86/cpuid-autogen.h>
6 
7 #define FEATURESET_1d     0 /* 0x00000001.edx      */
8 #define FEATURESET_1c     1 /* 0x00000001.ecx      */
9 #define FEATURESET_e1d    2 /* 0x80000001.edx      */
10 #define FEATURESET_e1c    3 /* 0x80000001.ecx      */
11 #define FEATURESET_Da1    4 /* 0x0000000d:1.eax    */
12 #define FEATURESET_7b0    5 /* 0x00000007:0.ebx    */
13 #define FEATURESET_7c0    6 /* 0x00000007:0.ecx    */
14 #define FEATURESET_e7d    7 /* 0x80000007.edx      */
15 #define FEATURESET_e8b    8 /* 0x80000008.ebx      */
16 #define FEATURESET_7d0    9 /* 0x00000007:0.edx    */
17 #define FEATURESET_7a1   10 /* 0x00000007:1.eax    */
18 
19 struct cpuid_leaf
20 {
21     uint32_t a, b, c, d;
22 };
23 
24 /*
25  * Versions of GCC before 5 unconditionally reserve %rBX as the PIC hard
26  * register, and are unable to cope with spilling it.  This results in a
27  * rather cryptic error:
28  *    error: inconsistent operand constraints in an ‘asm’
29  *
30  * In affected situations, work around the issue by using a separate register
31  * to hold the the %rBX output, and xchg twice to leave %rBX preserved around
32  * the asm() statement.
33  */
34 #if defined(__PIC__) && __GNUC__ < 5 && !defined(__clang__) && defined(__i386__)
35 # define XCHG_BX "xchg %%ebx, %[bx];"
36 # define BX_CON [bx] "=&r"
37 #elif defined(__PIC__) && __GNUC__ < 5 && !defined(__clang__) && \
38     defined(__x86_64__) && (defined(__code_model_medium__) || \
39                             defined(__code_model_large__))
40 # define XCHG_BX "xchg %%rbx, %q[bx];"
41 # define BX_CON [bx] "=&r"
42 #else
43 # define XCHG_BX ""
44 # define BX_CON "=&b"
45 #endif
46 
cpuid_leaf(uint32_t leaf,struct cpuid_leaf * l)47 static inline void cpuid_leaf(uint32_t leaf, struct cpuid_leaf *l)
48 {
49     asm ( XCHG_BX
50           "cpuid;"
51           XCHG_BX
52           : "=a" (l->a), BX_CON (l->b), "=&c" (l->c), "=&d" (l->d)
53           : "a" (leaf) );
54 }
55 
cpuid_count_leaf(uint32_t leaf,uint32_t subleaf,struct cpuid_leaf * l)56 static inline void cpuid_count_leaf(
57     uint32_t leaf, uint32_t subleaf, struct cpuid_leaf *l)
58 {
59     asm ( XCHG_BX
60           "cpuid;"
61           XCHG_BX
62           : "=a" (l->a), BX_CON (l->b), "=c" (l->c), "=&d" (l->d)
63           : "a" (leaf), "c" (subleaf) );
64 }
65 
66 #undef BX_CON
67 #undef XCHG
68 
69 /**
70  * Given the vendor id from CPUID leaf 0, look up Xen's internal integer
71  * vendor ID.  Returns X86_VENDOR_UNKNOWN for any unknown vendor.
72  */
73 unsigned int x86_cpuid_lookup_vendor(uint32_t ebx, uint32_t ecx, uint32_t edx);
74 
75 /**
76  * Given Xen's internal vendor ID, return a string suitable for printing.
77  * Returns "Unknown" for any unrecognised ID.
78  */
79 const char *x86_cpuid_vendor_to_str(unsigned int vendor);
80 
81 #define CPUID_GUEST_NR_BASIC      (0xdu + 1)
82 #define CPUID_GUEST_NR_CACHE      (5u + 1)
83 #define CPUID_GUEST_NR_FEAT       (1u + 1)
84 #define CPUID_GUEST_NR_TOPO       (1u + 1)
85 #define CPUID_GUEST_NR_XSTATE     (62u + 1)
86 #define CPUID_GUEST_NR_EXTD_INTEL (0x8u + 1)
87 #define CPUID_GUEST_NR_EXTD_AMD   (0x1cu + 1)
88 #define CPUID_GUEST_NR_EXTD       MAX(CPUID_GUEST_NR_EXTD_INTEL, \
89                                       CPUID_GUEST_NR_EXTD_AMD)
90 
91 /*
92  * Maximum number of leaves a struct cpuid_policy turns into when serialised
93  * for interaction with the toolstack.  (Sum of all leaves in each union, less
94  * the entries in basic which sub-unions hang off of.)
95  */
96 #define CPUID_MAX_SERIALISED_LEAVES                     \
97     (CPUID_GUEST_NR_BASIC +                             \
98      CPUID_GUEST_NR_FEAT   - !!CPUID_GUEST_NR_FEAT +    \
99      CPUID_GUEST_NR_CACHE  - !!CPUID_GUEST_NR_CACHE +   \
100      CPUID_GUEST_NR_TOPO   - !!CPUID_GUEST_NR_TOPO +    \
101      CPUID_GUEST_NR_XSTATE - !!CPUID_GUEST_NR_XSTATE +  \
102      CPUID_GUEST_NR_EXTD + 2 /* hv_limit and hv2_limit */ )
103 
104 struct cpuid_policy
105 {
106 #define DECL_BITFIELD(word) _DECL_BITFIELD(FEATURESET_ ## word)
107 #define _DECL_BITFIELD(x)   __DECL_BITFIELD(x)
108 #define __DECL_BITFIELD(x)  CPUID_BITFIELD_ ## x
109 
110     /* Basic leaves: 0x000000xx */
111     union {
112         struct cpuid_leaf raw[CPUID_GUEST_NR_BASIC];
113         struct {
114             /* Leaf 0x0 - Max and vendor. */
115             uint32_t max_leaf, vendor_ebx, vendor_ecx, vendor_edx;
116 
117             /* Leaf 0x1 - Family/model/stepping and features. */
118             uint32_t raw_fms;
119             uint8_t :8,       /* Brand ID. */
120                 clflush_size, /* Number of 8-byte blocks per cache line. */
121                 lppp,         /* Logical processors per package. */
122                 apic_id;      /* Initial APIC ID. */
123             union {
124                 uint32_t _1c;
125                 struct { DECL_BITFIELD(1c); };
126             };
127             union {
128                 uint32_t _1d;
129                 struct { DECL_BITFIELD(1d); };
130             };
131 
132             /* Leaf 0x2 - TLB/Cache/Prefetch. */
133             uint8_t l2_nr_queries; /* Documented as fixed to 1. */
134             uint8_t l2_desc[15];
135 
136             uint64_t :64, :64; /* Leaf 0x3 - PSN. */
137             uint64_t :64, :64; /* Leaf 0x4 - Structured Cache. */
138             uint64_t :64, :64; /* Leaf 0x5 - MONITOR. */
139             uint64_t :64, :64; /* Leaf 0x6 - Therm/Perf. */
140             uint64_t :64, :64; /* Leaf 0x7 - Structured Features. */
141             uint64_t :64, :64; /* Leaf 0x8 - rsvd */
142             uint64_t :64, :64; /* Leaf 0x9 - DCA */
143 
144             /* Leaf 0xa - Intel PMU. */
145             uint8_t pmu_version, _pmu[15];
146 
147             uint64_t :64, :64; /* Leaf 0xb - Topology. */
148             uint64_t :64, :64; /* Leaf 0xc - rsvd */
149             uint64_t :64, :64; /* Leaf 0xd - XSTATE. */
150         };
151     } basic;
152 
153     /* Structured cache leaf: 0x00000004[xx] */
154     union {
155         struct cpuid_leaf raw[CPUID_GUEST_NR_CACHE];
156         struct cpuid_cache_leaf {
157             uint32_t /* a */ type:5, level:3;
158             bool self_init:1, fully_assoc:1;
159             uint32_t :4, threads_per_cache:12, cores_per_package:6;
160             uint32_t /* b */ line_size:12, partitions:10, ways:10;
161             uint32_t /* c */ sets;
162             bool /* d */ wbinvd:1, inclusive:1, complex:1;
163         } subleaf[CPUID_GUEST_NR_CACHE];
164     } cache;
165 
166     /* Structured feature leaf: 0x00000007[xx] */
167     union {
168         struct cpuid_leaf raw[CPUID_GUEST_NR_FEAT];
169         struct {
170             /* Subleaf 0. */
171             uint32_t max_subleaf;
172             union {
173                 uint32_t _7b0;
174                 struct { DECL_BITFIELD(7b0); };
175             };
176             union {
177                 uint32_t _7c0;
178                 struct { DECL_BITFIELD(7c0); };
179             };
180             union {
181                 uint32_t _7d0;
182                 struct { DECL_BITFIELD(7d0); };
183             };
184 
185             /* Subleaf 1. */
186             union {
187                 uint32_t _7a1;
188                 struct { DECL_BITFIELD(7a1); };
189             };
190         };
191     } feat;
192 
193     /* Extended topology enumeration: 0x0000000B[xx] */
194     union {
195         struct cpuid_leaf raw[CPUID_GUEST_NR_TOPO];
196         struct cpuid_topo_leaf {
197             uint32_t id_shift:5, :27;
198             uint16_t nr_logical, :16;
199             uint8_t level, type, :8, :8;
200             uint32_t x2apic_id;
201         } subleaf[CPUID_GUEST_NR_TOPO];
202     } topo;
203 
204     /* Xstate feature leaf: 0x0000000D[xx] */
205     union {
206         struct cpuid_leaf raw[CPUID_GUEST_NR_XSTATE];
207 
208         struct {
209             /* Subleaf 0. */
210             uint32_t xcr0_low, /* b */:32, max_size, xcr0_high;
211 
212             /* Subleaf 1. */
213             union {
214                 uint32_t Da1;
215                 struct { DECL_BITFIELD(Da1); };
216             };
217             uint32_t /* b */:32, xss_low, xss_high;
218         };
219 
220         /* Per-component common state.  Valid for i >= 2. */
221         struct {
222             uint32_t size, offset;
223             bool xss:1, align:1;
224             uint32_t _res_d;
225         } comp[CPUID_GUEST_NR_XSTATE];
226     } xstate;
227 
228     /* Extended leaves: 0x800000xx */
229     union {
230         struct cpuid_leaf raw[CPUID_GUEST_NR_EXTD];
231         struct {
232             /* Leaf 0x80000000 - Max and vendor. */
233             uint32_t max_leaf, vendor_ebx, vendor_ecx, vendor_edx;
234 
235             /* Leaf 0x80000001 - Family/model/stepping and features. */
236             uint32_t raw_fms, /* b */:32;
237             union {
238                 uint32_t e1c;
239                 struct { DECL_BITFIELD(e1c); };
240             };
241             union {
242                 uint32_t e1d;
243                 struct { DECL_BITFIELD(e1d); };
244             };
245 
246             uint64_t :64, :64; /* Brand string. */
247             uint64_t :64, :64; /* Brand string. */
248             uint64_t :64, :64; /* Brand string. */
249             uint64_t :64, :64; /* L1 cache/TLB. */
250             uint64_t :64, :64; /* L2/3 cache/TLB. */
251 
252             /* Leaf 0x80000007 - Advanced Power Management. */
253             uint32_t /* a */:32, /* b */:32, /* c */:32;
254             union {
255                 uint32_t e7d;
256                 struct { DECL_BITFIELD(e7d); };
257             };
258 
259             /* Leaf 0x80000008 - Misc addr/feature info. */
260             uint8_t maxphysaddr, maxlinaddr, :8, :8;
261             union {
262                 uint32_t e8b;
263                 struct { DECL_BITFIELD(e8b); };
264             };
265             uint32_t nc:8, :4, apic_id_size:4, :16;
266             uint32_t /* d */:32;
267         };
268     } extd;
269 
270 #undef __DECL_BITFIELD
271 #undef _DECL_BITFIELD
272 #undef DECL_BITFIELD
273 
274     /* Toolstack selected Hypervisor max_leaf (if non-zero). */
275     uint8_t hv_limit, hv2_limit;
276 
277     /* Value calculated from raw data above. */
278     uint8_t x86_vendor;
279 };
280 
281 /* Fill in a featureset bitmap from a CPUID policy. */
cpuid_policy_to_featureset(const struct cpuid_policy * p,uint32_t fs[FEATURESET_NR_ENTRIES])282 static inline void cpuid_policy_to_featureset(
283     const struct cpuid_policy *p, uint32_t fs[FEATURESET_NR_ENTRIES])
284 {
285     fs[FEATURESET_1d]  = p->basic._1d;
286     fs[FEATURESET_1c]  = p->basic._1c;
287     fs[FEATURESET_e1d] = p->extd.e1d;
288     fs[FEATURESET_e1c] = p->extd.e1c;
289     fs[FEATURESET_Da1] = p->xstate.Da1;
290     fs[FEATURESET_7b0] = p->feat._7b0;
291     fs[FEATURESET_7c0] = p->feat._7c0;
292     fs[FEATURESET_e7d] = p->extd.e7d;
293     fs[FEATURESET_e8b] = p->extd.e8b;
294     fs[FEATURESET_7d0] = p->feat._7d0;
295     fs[FEATURESET_7a1] = p->feat._7a1;
296 }
297 
298 /* Fill in a CPUID policy from a featureset bitmap. */
cpuid_featureset_to_policy(const uint32_t fs[FEATURESET_NR_ENTRIES],struct cpuid_policy * p)299 static inline void cpuid_featureset_to_policy(
300     const uint32_t fs[FEATURESET_NR_ENTRIES], struct cpuid_policy *p)
301 {
302     p->basic._1d  = fs[FEATURESET_1d];
303     p->basic._1c  = fs[FEATURESET_1c];
304     p->extd.e1d   = fs[FEATURESET_e1d];
305     p->extd.e1c   = fs[FEATURESET_e1c];
306     p->xstate.Da1 = fs[FEATURESET_Da1];
307     p->feat._7b0  = fs[FEATURESET_7b0];
308     p->feat._7c0  = fs[FEATURESET_7c0];
309     p->extd.e7d   = fs[FEATURESET_e7d];
310     p->extd.e8b   = fs[FEATURESET_e8b];
311     p->feat._7d0  = fs[FEATURESET_7d0];
312     p->feat._7a1  = fs[FEATURESET_7a1];
313 }
314 
cpuid_policy_xcr0_max(const struct cpuid_policy * p)315 static inline uint64_t cpuid_policy_xcr0_max(const struct cpuid_policy *p)
316 {
317     return ((uint64_t)p->xstate.xcr0_high << 32) | p->xstate.xcr0_low;
318 }
319 
cpuid_policy_xstates(const struct cpuid_policy * p)320 static inline uint64_t cpuid_policy_xstates(const struct cpuid_policy *p)
321 {
322     uint64_t val = p->xstate.xcr0_high | p->xstate.xss_high;
323 
324     return (val << 32) | p->xstate.xcr0_low | p->xstate.xss_low;
325 }
326 
327 const uint32_t *x86_cpuid_lookup_deep_deps(uint32_t feature);
328 
329 /**
330  * Recalculate the content in a CPUID policy which is derived from raw data.
331  */
332 void x86_cpuid_policy_recalc_synth(struct cpuid_policy *p);
333 
334 /**
335  * Fill a CPUID policy using the native CPUID instruction.
336  *
337  * No sanitisation is performed, but synthesised values are calculated.
338  * Values may be influenced by a hypervisor or from masking/faulting
339  * configuration.
340  */
341 void x86_cpuid_policy_fill_native(struct cpuid_policy *p);
342 
343 /**
344  * Clear leaf data beyond the policies max leaf/subleaf settings.
345  *
346  * Policy serialisation purposefully omits out-of-range leaves, because there
347  * are a large number of them due to vendor differences.  However, when
348  * constructing new policies (e.g. levelling down), it is possible to end up
349  * with out-of-range leaves with stale content in them.  This helper clears
350  * them.
351  */
352 void x86_cpuid_policy_clear_out_of_range_leaves(struct cpuid_policy *p);
353 
354 #ifdef __XEN__
355 #include <public/arch-x86/xen.h>
356 typedef XEN_GUEST_HANDLE_64(xen_cpuid_leaf_t) cpuid_leaf_buffer_t;
357 #else
358 #include <xen/arch-x86/xen.h>
359 typedef xen_cpuid_leaf_t cpuid_leaf_buffer_t[];
360 #endif
361 
362 /**
363  * Serialise a cpuid_policy object into an array of cpuid leaves.
364  *
365  * @param policy     The cpuid_policy to serialise.
366  * @param leaves     The array of leaves to serialise into.
367  * @param nr_entries The number of entries in 'leaves'.
368  * @returns -errno
369  *
370  * Writes at most CPUID_MAX_SERIALISED_LEAVES.  May fail with -ENOBUFS if the
371  * leaves array is too short.  On success, nr_entries is updated with the
372  * actual number of leaves written.
373  */
374 int x86_cpuid_copy_to_buffer(const struct cpuid_policy *policy,
375                              cpuid_leaf_buffer_t leaves, uint32_t *nr_entries);
376 
377 /**
378  * Unserialise a cpuid_policy object from an array of cpuid leaves.
379  *
380  * @param policy      The cpuid_policy to unserialise into.
381  * @param leaves      The array of leaves to unserialise from.
382  * @param nr_entries  The number of entries in 'leaves'.
383  * @param err_leaf    Optional hint for error diagnostics.
384  * @param err_subleaf Optional hint for error diagnostics.
385  * @returns -errno
386  *
387  * Reads at most CPUID_MAX_SERIALISED_LEAVES.  May return -ERANGE if an
388  * incoming leaf is out of range of cpuid_policy, in which case the optional
389  * err_* pointers will identify the out-of-range indicies.
390  *
391  * No content validation of in-range leaves is performed.  Synthesised data is
392  * recalculated.
393  */
394 int x86_cpuid_copy_from_buffer(struct cpuid_policy *policy,
395                                const cpuid_leaf_buffer_t leaves,
396                                uint32_t nr_entries, uint32_t *err_leaf,
397                                uint32_t *err_subleaf);
398 
399 #endif /* !XEN_LIB_X86_CPUID_H */
400 
401 /*
402  * Local variables:
403  * mode: C
404  * c-file-style: "BSD"
405  * c-basic-offset: 4
406  * tab-width: 4
407  * indent-tabs-mode: nil
408  * End:
409  */
410