arch/powerpc/kvm/book3s_64_slb.S

   1 /*
   2  * This program is free software; you can redistribute it and/or modify
   3  * it under the terms of the GNU General Public License, version 2, as
   4  * published by the Free Software Foundation.
   5  *
   6  * This program is distributed in the hope that it will be useful,
   7  * but WITHOUT ANY WARRANTY; without even the implied warranty of
   8  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   9  * GNU General Public License for more details.
  10  *
  11  * You should have received a copy of the GNU General Public License
  12  * along with this program; if not, write to the Free Software
  13  * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  14  *
  15  * Copyright SUSE Linux Products GmbH 2009
  16  *
  17  * Authors: Alexander Graf <agraf@suse.de>
  18  */
  19
  20 #define SHADOW_SLB_ESID(num)    (SLBSHADOW_SAVEAREA + (num * 0x10))
  21 #define SHADOW_SLB_VSID(num)    (SLBSHADOW_SAVEAREA + (num * 0x10) + 0x8)
  22 #define UNBOLT_SLB_ENTRY(num) \
  23         ld      r9, SHADOW_SLB_ESID(num)(r12); \
  24         /* Invalid? Skip. */; \
  25         rldicl. r0, r9, 37, 63; \
  26         beq     slb_entry_skip_ ## num; \
  27         xoris   r9, r9, SLB_ESID_V@h; \
  28         std     r9, SHADOW_SLB_ESID(num)(r12); \
  29   slb_entry_skip_ ## num:
  30
  31 #define REBOLT_SLB_ENTRY(num) \
  32         ld      r10, SHADOW_SLB_ESID(num)(r11); \
  33         cmpdi   r10, 0; \
  34         beq     slb_exit_skip_ ## num; \
  35         oris    r10, r10, SLB_ESID_V@h; \
  36         ld      r9, SHADOW_SLB_VSID(num)(r11); \
  37         slbmte  r9, r10; \
  38         std     r10, SHADOW_SLB_ESID(num)(r11); \
  39 slb_exit_skip_ ## num:
  40
  41 /******************************************************************************
  42  *                                                                            *
  43  *                               Entry code                                   *
  44  *                                                                            *
  45  *****************************************************************************/
  46
  47 .global kvmppc_handler_trampoline_enter
  48 kvmppc_handler_trampoline_enter:
  49
  50         /* Required state:
  51          *
  52          * MSR = ~IR|DR
  53          * R13 = PACA
  54          * R1 = host R1
  55          * R2 = host R2
  56          * R9 = guest IP
  57          * R10 = guest MSR
  58          * all other GPRS = free
  59          * PACA[KVM_CR] = guest CR
  60          * PACA[KVM_XER] = guest XER
  61          */
  62
  63         mtsrr0  r9
  64         mtsrr1  r10
  65
  66         /* Activate guest mode, so faults get handled by KVM */
  67         li      r11, KVM_GUEST_MODE_GUEST
  68         stb     r11, PACA_KVM_IN_GUEST(r13)
  69
  70         /* Remove LPAR shadow entries */
  71
  72 #if SLB_NUM_BOLTED == 3
  73
  74         ld      r12, PACA_SLBSHADOWPTR(r13)
  75
  76         /* Save off the first entry so we can slbie it later */
  77         ld      r10, SHADOW_SLB_ESID(0)(r12)
  78         ld      r11, SHADOW_SLB_VSID(0)(r12)
  79
  80         /* Remove bolted entries */
  81         UNBOLT_SLB_ENTRY(0)
  82         UNBOLT_SLB_ENTRY(1)
  83         UNBOLT_SLB_ENTRY(2)
  84
  85 #else
  86 #error unknown number of bolted entries
  87 #endif
  88
  89         /* Flush SLB */
  90
  91         slbia
  92
  93         /* r0 = esid & ESID_MASK */
  94         rldicr  r10, r10, 0, 35
  95         /* r0 |= CLASS_BIT(VSID) */
  96         rldic   r12, r11, 56 - 36, 36
  97         or      r10, r10, r12
  98         slbie   r10
  99
 100         isync
 101
 102         /* Fill SLB with our shadow */
 103
 104         lbz     r12, PACA_KVM_SLB_MAX(r13)
 105         mulli   r12, r12, 16
 106         addi    r12, r12, PACA_KVM_SLB
 107         add     r12, r12, r13
 108
 109         /* for (r11 = kvm_slb; r11 < kvm_slb + kvm_slb_size; r11+=slb_entry) */
 110         li      r11, PACA_KVM_SLB
 111         add     r11, r11, r13
 112
 113 slb_loop_enter:
 114
 115         ld      r10, 0(r11)
 116
 117         rldicl. r0, r10, 37, 63
 118         beq     slb_loop_enter_skip
 119
 120         ld      r9, 8(r11)
 121         slbmte  r9, r10
 122
 123 slb_loop_enter_skip:
 124         addi    r11, r11, 16
 125         cmpd    cr0, r11, r12
 126         blt     slb_loop_enter
 127
 128 slb_do_enter:
 129
 130         /* Enter guest */
 131
 132         ld      r0, (PACA_KVM_R0)(r13)
 133         ld      r1, (PACA_KVM_R1)(r13)
 134         ld      r2, (PACA_KVM_R2)(r13)
 135         ld      r3, (PACA_KVM_R3)(r13)
 136         ld      r4, (PACA_KVM_R4)(r13)
 137         ld      r5, (PACA_KVM_R5)(r13)
 138         ld      r6, (PACA_KVM_R6)(r13)
 139         ld      r7, (PACA_KVM_R7)(r13)
 140         ld      r8, (PACA_KVM_R8)(r13)
 141         ld      r9, (PACA_KVM_R9)(r13)
 142         ld      r10, (PACA_KVM_R10)(r13)
 143         ld      r12, (PACA_KVM_R12)(r13)
 144
 145         lwz     r11, (PACA_KVM_CR)(r13)
 146         mtcr    r11
 147
 148         ld      r11, (PACA_KVM_XER)(r13)
 149         mtxer   r11
 150
 151         ld      r11, (PACA_KVM_R11)(r13)
 152         ld      r13, (PACA_KVM_R13)(r13)
 153
 154         RFI
 155 kvmppc_handler_trampoline_enter_end:
 156
 157
 158
 159 /******************************************************************************
 160  *                                                                            *
 161  *                               Exit code                                    *
 162  *                                                                            *
 163  *****************************************************************************/
 164
 165 .global kvmppc_handler_trampoline_exit
 166 kvmppc_handler_trampoline_exit:
 167
 168         /* Register usage at this point:
 169          *
 170          * SPRG_SCRATCH0     = guest R13
 171          * R12               = exit handler id
 172          * R13               = PACA
 173          * PACA.KVM.SCRATCH0 = guest R12
 174          * PACA.KVM.SCRATCH1 = guest CR
 175          *
 176          */
 177
 178         /* Save registers */
 179
 180         std     r0, PACA_KVM_R0(r13)
 181         std     r1, PACA_KVM_R1(r13)
 182         std     r2, PACA_KVM_R2(r13)
 183         std     r3, PACA_KVM_R3(r13)
 184         std     r4, PACA_KVM_R4(r13)
 185         std     r5, PACA_KVM_R5(r13)
 186         std     r6, PACA_KVM_R6(r13)
 187         std     r7, PACA_KVM_R7(r13)
 188         std     r8, PACA_KVM_R8(r13)
 189         std     r9, PACA_KVM_R9(r13)
 190         std     r10, PACA_KVM_R10(r13)
 191         std     r11, PACA_KVM_R11(r13)
 192
 193         /* Restore R1/R2 so we can handle faults */
 194         ld      r1, PACA_KVM_HOST_R1(r13)
 195         ld      r2, PACA_KVM_HOST_R2(r13)
 196
 197         /* Save guest PC and MSR in GPRs */
 198         mfsrr0  r3
 199         mfsrr1  r4
 200
 201         /* Get scratch'ed off registers */
 202         mfspr   r9, SPRN_SPRG_SCRATCH0
 203         std     r9, PACA_KVM_R13(r13)
 204
 205         ld      r8, PACA_KVM_SCRATCH0(r13)
 206         std     r8, PACA_KVM_R12(r13)
 207
 208         lwz     r7, PACA_KVM_SCRATCH1(r13)
 209         stw     r7, PACA_KVM_CR(r13)
 210
 211         /* Save more register state  */
 212
 213         mfxer   r6
 214         stw     r6, PACA_KVM_XER(r13)
 215
 216         mfdar   r5
 217         mfdsisr r6
 218
 219         /*
 220          * In order for us to easily get the last instruction,
 221          * we got the #vmexit at, we exploit the fact that the
 222          * virtual layout is still the same here, so we can just
 223          * ld from the guest's PC address
 224          */
 225
 226         /* We only load the last instruction when it's safe */
 227         cmpwi   r12, BOOK3S_INTERRUPT_DATA_STORAGE
 228         beq     ld_last_inst
 229         cmpwi   r12, BOOK3S_INTERRUPT_PROGRAM
 230         beq     ld_last_inst
 231
 232         b       no_ld_last_inst
 233
 234 ld_last_inst:
 235         /* Save off the guest instruction we're at */
 236
 237         /* Set guest mode to 'jump over instruction' so if lwz faults
 238          * we'll just continue at the next IP. */
 239         li      r9, KVM_GUEST_MODE_SKIP
 240         stb     r9, PACA_KVM_IN_GUEST(r13)
 241
 242         /*    1) enable paging for data */
 243         mfmsr   r9
 244         ori     r11, r9, MSR_DR                 /* Enable paging for data */
 245         mtmsr   r11
 246         /*    2) fetch the instruction */
 247         li      r0, KVM_INST_FETCH_FAILED       /* In case lwz faults */
 248         lwz     r0, 0(r3)
 249         /*    3) disable paging again */
 250         mtmsr   r9
 251
 252 no_ld_last_inst:
 253
 254         /* Unset guest mode */
 255         li      r9, KVM_GUEST_MODE_NONE
 256         stb     r9, PACA_KVM_IN_GUEST(r13)
 257
 258         /* Restore bolted entries from the shadow and fix it along the way */
 259
 260         /* We don't store anything in entry 0, so we don't need to take care of it */
 261         slbia
 262         isync
 263
 264 #if SLB_NUM_BOLTED == 3
 265
 266         ld      r11, PACA_SLBSHADOWPTR(r13)
 267
 268         REBOLT_SLB_ENTRY(0)
 269         REBOLT_SLB_ENTRY(1)
 270         REBOLT_SLB_ENTRY(2)
 271
 272 #else
 273 #error unknown number of bolted entries
 274 #endif
 275
 276 slb_do_exit:
 277
 278         /* Register usage at this point:
 279          *
 280          * R0         = guest last inst
 281          * R1         = host R1
 282          * R2         = host R2
 283          * R3         = guest PC
 284          * R4         = guest MSR
 285          * R5         = guest DAR
 286          * R6         = guest DSISR
 287          * R12        = exit handler id
 288          * R13        = PACA
 289          * PACA.KVM.* = guest *
 290          *
 291          */
 292
 293         /* RFI into the highmem handler */
 294         mfmsr   r7
 295         ori     r7, r7, MSR_IR|MSR_DR|MSR_RI    /* Enable paging */
 296         mtsrr1  r7
 297         ld      r8, PACA_KVM_VMHANDLER(r13)     /* Highmem handler address */
 298         mtsrr0  r8
 299
 300         RFI
 301 kvmppc_handler_trampoline_exit_end:
 302