arch/x86/include/asm/xen/interface.h

   1 /******************************************************************************
   2  * arch-x86_32.h
   3  *
   4  * Guest OS interface to x86 Xen.
   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) 2004-2006, K A Fraser
  25  */
  26
  27 #ifndef _ASM_X86_XEN_INTERFACE_H
  28 #define _ASM_X86_XEN_INTERFACE_H
  29
  30 /*
  31  * XEN_GUEST_HANDLE represents a guest pointer, when passed as a field
  32  * in a struct in memory.
  33  * XEN_GUEST_HANDLE_PARAM represent a guest pointer, when passed as an
  34  * hypercall argument.
  35  * XEN_GUEST_HANDLE_PARAM and XEN_GUEST_HANDLE are the same on X86 but
  36  * they might not be on other architectures.
  37  */
  38 #ifdef __XEN__
  39 #define __DEFINE_GUEST_HANDLE(name, type) \
  40     typedef struct { type *p; } __guest_handle_ ## name
  41 #else
  42 #define __DEFINE_GUEST_HANDLE(name, type) \
  43     typedef type * __guest_handle_ ## name
  44 #endif
  45
  46 #define DEFINE_GUEST_HANDLE_STRUCT(name) \
  47         __DEFINE_GUEST_HANDLE(name, struct name)
  48 #define DEFINE_GUEST_HANDLE(name) __DEFINE_GUEST_HANDLE(name, name)
  49 #define GUEST_HANDLE(name)        __guest_handle_ ## name
  50
  51 #ifdef __XEN__
  52 #if defined(__i386__)
  53 #define set_xen_guest_handle(hnd, val)                  \
  54         do {                                            \
  55                 if (sizeof(hnd) == 8)                   \
  56                         *(uint64_t *)&(hnd) = 0;        \
  57                 (hnd).p = val;                          \
  58         } while (0)
  59 #elif defined(__x86_64__)
  60 #define set_xen_guest_handle(hnd, val)  do { (hnd).p = val; } while (0)
  61 #endif
  62 #else
  63 #if defined(__i386__)
  64 #define set_xen_guest_handle(hnd, val)                  \
  65         do {                                            \
  66                 if (sizeof(hnd) == 8)                   \
  67                         *(uint64_t *)&(hnd) = 0;        \
  68                 (hnd) = val;                            \
  69         } while (0)
  70 #elif defined(__x86_64__)
  71 #define set_xen_guest_handle(hnd, val)  do { (hnd) = val; } while (0)
  72 #endif
  73 #endif
  74
  75 #ifndef __ASSEMBLY__
  76 /* Explicitly size integers that represent pfns in the public interface
  77  * with Xen so that on ARM we can have one ABI that works for 32 and 64
  78  * bit guests. */
  79 typedef unsigned long xen_pfn_t;
  80 #define PRI_xen_pfn "lx"
  81 typedef unsigned long xen_ulong_t;
  82 #define PRI_xen_ulong "lx"
  83 typedef long xen_long_t;
  84 #define PRI_xen_long "lx"
  85
  86 /* Guest handles for primitive C types. */
  87 __DEFINE_GUEST_HANDLE(uchar, unsigned char);
  88 __DEFINE_GUEST_HANDLE(uint,  unsigned int);
  89 DEFINE_GUEST_HANDLE(char);
  90 DEFINE_GUEST_HANDLE(int);
  91 DEFINE_GUEST_HANDLE(void);
  92 DEFINE_GUEST_HANDLE(uint64_t);
  93 DEFINE_GUEST_HANDLE(uint32_t);
  94 DEFINE_GUEST_HANDLE(xen_pfn_t);
  95 DEFINE_GUEST_HANDLE(xen_ulong_t);
  96 #endif
  97
  98 #ifndef HYPERVISOR_VIRT_START
  99 #define HYPERVISOR_VIRT_START mk_unsigned_long(__HYPERVISOR_VIRT_START)
 100 #endif
 101
 102 #define MACH2PHYS_VIRT_START  mk_unsigned_long(__MACH2PHYS_VIRT_START)
 103 #define MACH2PHYS_VIRT_END    mk_unsigned_long(__MACH2PHYS_VIRT_END)
 104 #define MACH2PHYS_NR_ENTRIES  ((MACH2PHYS_VIRT_END-MACH2PHYS_VIRT_START)>>__MACH2PHYS_SHIFT)
 105
 106 /* Maximum number of virtual CPUs in multi-processor guests. */
 107 #define MAX_VIRT_CPUS 32
 108
 109 /*
 110  * SEGMENT DESCRIPTOR TABLES
 111  */
 112 /*
 113  * A number of GDT entries are reserved by Xen. These are not situated at the
 114  * start of the GDT because some stupid OSes export hard-coded selector values
 115  * in their ABI. These hard-coded values are always near the start of the GDT,
 116  * so Xen places itself out of the way, at the far end of the GDT.
 117  *
 118  * NB The LDT is set using the MMUEXT_SET_LDT op of HYPERVISOR_mmuext_op
 119  */
 120 #define FIRST_RESERVED_GDT_PAGE  14
 121 #define FIRST_RESERVED_GDT_BYTE  (FIRST_RESERVED_GDT_PAGE * 4096)
 122 #define FIRST_RESERVED_GDT_ENTRY (FIRST_RESERVED_GDT_BYTE / 8)
 123
 124 /*
 125  * Send an array of these to HYPERVISOR_set_trap_table().
 126  * Terminate the array with a sentinel entry, with traps[].address==0.
 127  * The privilege level specifies which modes may enter a trap via a software
 128  * interrupt. On x86/64, since rings 1 and 2 are unavailable, we allocate
 129  * privilege levels as follows:
 130  *  Level == 0: No one may enter
 131  *  Level == 1: Kernel may enter
 132  *  Level == 2: Kernel may enter
 133  *  Level == 3: Everyone may enter
 134  */
 135 #define TI_GET_DPL(_ti)         ((_ti)->flags & 3)
 136 #define TI_GET_IF(_ti)          ((_ti)->flags & 4)
 137 #define TI_SET_DPL(_ti, _dpl)   ((_ti)->flags |= (_dpl))
 138 #define TI_SET_IF(_ti, _if)     ((_ti)->flags |= ((!!(_if))<<2))
 139
 140 #ifndef __ASSEMBLY__
 141 struct trap_info {
 142     uint8_t       vector;  /* exception vector                              */
 143     uint8_t       flags;   /* 0-3: privilege level; 4: clear event enable?  */
 144     uint16_t      cs;      /* code selector                                 */
 145     unsigned long address; /* code offset                                   */
 146 };
 147 DEFINE_GUEST_HANDLE_STRUCT(trap_info);
 148
 149 struct arch_shared_info {
 150         /*
 151          * Number of valid entries in the p2m table(s) anchored at
 152          * pfn_to_mfn_frame_list_list and/or p2m_vaddr.
 153          */
 154         unsigned long max_pfn;
 155         /*
 156          * Frame containing list of mfns containing list of mfns containing p2m.
 157          * A value of 0 indicates it has not yet been set up, ~0 indicates it
 158          * has been set to invalid e.g. due to the p2m being too large for the
 159          * 3-level p2m tree. In this case the linear mapper p2m list anchored
 160          * at p2m_vaddr is to be used.
 161          */
 162         xen_pfn_t pfn_to_mfn_frame_list_list;
 163         unsigned long nmi_reason;
 164         /*
 165          * Following three fields are valid if p2m_cr3 contains a value
 166          * different from 0.
 167          * p2m_cr3 is the root of the address space where p2m_vaddr is valid.
 168          * p2m_cr3 is in the same format as a cr3 value in the vcpu register
 169          * state and holds the folded machine frame number (via xen_pfn_to_cr3)
 170          * of a L3 or L4 page table.
 171          * p2m_vaddr holds the virtual address of the linear p2m list. All
 172          * entries in the range [0...max_pfn[ are accessible via this pointer.
 173          * p2m_generation will be incremented by the guest before and after each
 174          * change of the mappings of the p2m list. p2m_generation starts at 0
 175          * and a value with the least significant bit set indicates that a
 176          * mapping update is in progress. This allows guest external software
 177          * (e.g. in Dom0) to verify that read mappings are consistent and
 178          * whether they have changed since the last check.
 179          * Modifying a p2m element in the linear p2m list is allowed via an
 180          * atomic write only.
 181          */
 182         unsigned long p2m_cr3;          /* cr3 value of the p2m address space */
 183         unsigned long p2m_vaddr;        /* virtual address of the p2m list */
 184         unsigned long p2m_generation;   /* generation count of p2m mapping */
 185 };
 186 #endif  /* !__ASSEMBLY__ */
 187
 188 #ifdef CONFIG_X86_32
 189 #include <asm/xen/interface_32.h>
 190 #else
 191 #include <asm/xen/interface_64.h>
 192 #endif
 193
 194 #include <asm/pvclock-abi.h>
 195
 196 #ifndef __ASSEMBLY__
 197 /*
 198  * The following is all CPU context. Note that the fpu_ctxt block is filled
 199  * in by FXSAVE if the CPU has feature FXSR; otherwise FSAVE is used.
 200  *
 201  * Also note that when calling DOMCTL_setvcpucontext and VCPU_initialise
 202  * for HVM and PVH guests, not all information in this structure is updated:
 203  *
 204  * - For HVM guests, the structures read include: fpu_ctxt (if
 205  * VGCT_I387_VALID is set), flags, user_regs, debugreg[*]
 206  *
 207  * - PVH guests are the same as HVM guests, but additionally use ctrlreg[3] to
 208  * set cr3. All other fields not used should be set to 0.
 209  */
 210 struct vcpu_guest_context {
 211     /* FPU registers come first so they can be aligned for FXSAVE/FXRSTOR. */
 212     struct { char x[512]; } fpu_ctxt;       /* User-level FPU registers     */
 213 #define VGCF_I387_VALID                (1<<0)
 214 #define VGCF_IN_KERNEL                 (1<<2)
 215 #define _VGCF_i387_valid               0
 216 #define VGCF_i387_valid                (1<<_VGCF_i387_valid)
 217 #define _VGCF_in_kernel                2
 218 #define VGCF_in_kernel                 (1<<_VGCF_in_kernel)
 219 #define _VGCF_failsafe_disables_events 3
 220 #define VGCF_failsafe_disables_events  (1<<_VGCF_failsafe_disables_events)
 221 #define _VGCF_syscall_disables_events  4
 222 #define VGCF_syscall_disables_events   (1<<_VGCF_syscall_disables_events)
 223 #define _VGCF_online                   5
 224 #define VGCF_online                    (1<<_VGCF_online)
 225     unsigned long flags;                    /* VGCF_* flags                 */
 226     struct cpu_user_regs user_regs;         /* User-level CPU registers     */
 227     struct trap_info trap_ctxt[256];        /* Virtual IDT                  */
 228     unsigned long ldt_base, ldt_ents;       /* LDT (linear address, # ents) */
 229     unsigned long gdt_frames[16], gdt_ents; /* GDT (machine frames, # ents) */
 230     unsigned long kernel_ss, kernel_sp;     /* Virtual TSS (only SS1/SP1)   */
 231     /* NB. User pagetable on x86/64 is placed in ctrlreg[1]. */
 232     unsigned long ctrlreg[8];               /* CR0-CR7 (control registers)  */
 233     unsigned long debugreg[8];              /* DB0-DB7 (debug registers)    */
 234 #ifdef __i386__
 235     unsigned long event_callback_cs;        /* CS:EIP of event callback     */
 236     unsigned long event_callback_eip;
 237     unsigned long failsafe_callback_cs;     /* CS:EIP of failsafe callback  */
 238     unsigned long failsafe_callback_eip;
 239 #else
 240     unsigned long event_callback_eip;
 241     unsigned long failsafe_callback_eip;
 242     unsigned long syscall_callback_eip;
 243 #endif
 244     unsigned long vm_assist;                /* VMASST_TYPE_* bitmap */
 245 #ifdef __x86_64__
 246     /* Segment base addresses. */
 247     uint64_t      fs_base;
 248     uint64_t      gs_base_kernel;
 249     uint64_t      gs_base_user;
 250 #endif
 251 };
 252 DEFINE_GUEST_HANDLE_STRUCT(vcpu_guest_context);
 253
 254 /* AMD PMU registers and structures */
 255 struct xen_pmu_amd_ctxt {
 256         /*
 257          * Offsets to counter and control MSRs (relative to xen_pmu_arch.c.amd).
 258          * For PV(H) guests these fields are RO.
 259          */
 260         uint32_t counters;
 261         uint32_t ctrls;
 262
 263         /* Counter MSRs */
 264 #if defined(__STDC_VERSION__) && __STDC_VERSION__ >= 199901L
 265         uint64_t regs[];
 266 #elif defined(__GNUC__)
 267         uint64_t regs[0];
 268 #endif
 269 };
 270
 271 /* Intel PMU registers and structures */
 272 struct xen_pmu_cntr_pair {
 273         uint64_t counter;
 274         uint64_t control;
 275 };
 276
 277 struct xen_pmu_intel_ctxt {
 278         /*
 279          * Offsets to fixed and architectural counter MSRs (relative to
 280          * xen_pmu_arch.c.intel).
 281          * For PV(H) guests these fields are RO.
 282          */
 283         uint32_t fixed_counters;
 284         uint32_t arch_counters;
 285
 286         /* PMU registers */
 287         uint64_t global_ctrl;
 288         uint64_t global_ovf_ctrl;
 289         uint64_t global_status;
 290         uint64_t fixed_ctrl;
 291         uint64_t ds_area;
 292         uint64_t pebs_enable;
 293         uint64_t debugctl;
 294
 295         /* Fixed and architectural counter MSRs */
 296 #if defined(__STDC_VERSION__) && __STDC_VERSION__ >= 199901L
 297         uint64_t regs[];
 298 #elif defined(__GNUC__)
 299         uint64_t regs[0];
 300 #endif
 301 };
 302
 303 /* Sampled domain's registers */
 304 struct xen_pmu_regs {
 305         uint64_t ip;
 306         uint64_t sp;
 307         uint64_t flags;
 308         uint16_t cs;
 309         uint16_t ss;
 310         uint8_t cpl;
 311         uint8_t pad[3];
 312 };
 313
 314 /* PMU flags */
 315 #define PMU_CACHED         (1<<0) /* PMU MSRs are cached in the context */
 316 #define PMU_SAMPLE_USER    (1<<1) /* Sample is from user or kernel mode */
 317 #define PMU_SAMPLE_REAL    (1<<2) /* Sample is from realmode */
 318 #define PMU_SAMPLE_PV      (1<<3) /* Sample from a PV guest */
 319
 320 /*
 321  * Architecture-specific information describing state of the processor at
 322  * the time of PMU interrupt.
 323  * Fields of this structure marked as RW for guest should only be written by
 324  * the guest when PMU_CACHED bit in pmu_flags is set (which is done by the
 325  * hypervisor during PMU interrupt). Hypervisor will read updated data in
 326  * XENPMU_flush hypercall and clear PMU_CACHED bit.
 327  */
 328 struct xen_pmu_arch {
 329         union {
 330                 /*
 331                  * Processor's registers at the time of interrupt.
 332                  * WO for hypervisor, RO for guests.
 333                  */
 334                 struct xen_pmu_regs regs;
 335                 /*
 336                  * Padding for adding new registers to xen_pmu_regs in
 337                  * the future
 338                  */
 339 #define XENPMU_REGS_PAD_SZ  64
 340                 uint8_t pad[XENPMU_REGS_PAD_SZ];
 341         } r;
 342
 343         /* WO for hypervisor, RO for guest */
 344         uint64_t pmu_flags;
 345
 346         /*
 347          * APIC LVTPC register.
 348          * RW for both hypervisor and guest.
 349          * Only APIC_LVT_MASKED bit is loaded by the hypervisor into hardware
 350          * during XENPMU_flush or XENPMU_lvtpc_set.
 351          */
 352         union {
 353                 uint32_t lapic_lvtpc;
 354                 uint64_t pad;
 355         } l;
 356
 357         /*
 358          * Vendor-specific PMU registers.
 359          * RW for both hypervisor and guest (see exceptions above).
 360          * Guest's updates to this field are verified and then loaded by the
 361          * hypervisor into hardware during XENPMU_flush
 362          */
 363         union {
 364                 struct xen_pmu_amd_ctxt amd;
 365                 struct xen_pmu_intel_ctxt intel;
 366
 367                 /*
 368                  * Padding for contexts (fixed parts only, does not include
 369                  * MSR banks that are specified by offsets)
 370                  */
 371 #define XENPMU_CTXT_PAD_SZ  128
 372                 uint8_t pad[XENPMU_CTXT_PAD_SZ];
 373         } c;
 374 };
 375
 376 #endif  /* !__ASSEMBLY__ */
 377
 378 /*
 379  * Prefix forces emulation of some non-trapping instructions.
 380  * Currently only CPUID.
 381  */
 382 #include <asm/emulate_prefix.h>
 383
 384 #define XEN_EMULATE_PREFIX __ASM_FORM(.byte __XEN_EMULATE_PREFIX ;)
 385 #define XEN_CPUID          XEN_EMULATE_PREFIX __ASM_FORM(cpuid)
 386
 387 #endif /* _ASM_X86_XEN_INTERFACE_H */