LXR linux/arch/powerpc/kernel/kvm

   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 2010
  16 * Copyright 2010-2011 Freescale Semiconductor, Inc.
  17 *
  18 * Authors: Alexander Graf <agraf@suse.de>
  19 */
  20
  21#include <asm/ppc_asm.h>
  22#include <asm/kvm_asm.h>
  23#include <asm/reg.h>
  24#include <asm/page.h>
  25#include <asm/asm-offsets.h>
  26
  27#define KVM_MAGIC_PAGE          (-4096)
  28
  29#ifdef CONFIG_64BIT
  30#define LL64(reg, offs, reg2)   ld      reg, (offs)(reg2)
  31#define STL64(reg, offs, reg2)  std     reg, (offs)(reg2)
  32#else
  33#define LL64(reg, offs, reg2)   lwz     reg, (offs + 4)(reg2)
  34#define STL64(reg, offs, reg2)  stw     reg, (offs + 4)(reg2)
  35#endif
  36
  37#define SCRATCH_SAVE                                                    \
  38        /* Enable critical section. We are critical if                  \
  39           shared->critical == r1 */                                    \
  40        STL64(r1, KVM_MAGIC_PAGE + KVM_MAGIC_CRITICAL, 0);              \
  41                                                                        \
  42        /* Save state */                                                \
  43        PPC_STL r31, (KVM_MAGIC_PAGE + KVM_MAGIC_SCRATCH1)(0);          \
  44        PPC_STL r30, (KVM_MAGIC_PAGE + KVM_MAGIC_SCRATCH2)(0);          \
  45        mfcr    r31;                                                    \
  46        stw     r31, (KVM_MAGIC_PAGE + KVM_MAGIC_SCRATCH3)(0);
  47
  48#define SCRATCH_RESTORE                                                 \
  49        /* Restore state */                                             \
  50        PPC_LL  r31, (KVM_MAGIC_PAGE + KVM_MAGIC_SCRATCH1)(0);          \
  51        lwz     r30, (KVM_MAGIC_PAGE + KVM_MAGIC_SCRATCH3)(0);          \
  52        mtcr    r30;                                                    \
  53        PPC_LL  r30, (KVM_MAGIC_PAGE + KVM_MAGIC_SCRATCH2)(0);          \
  54                                                                        \
  55        /* Disable critical section. We are critical if                 \
  56           shared->critical == r1 and r2 is always != r1 */             \
  57        STL64(r2, KVM_MAGIC_PAGE + KVM_MAGIC_CRITICAL, 0);
  58
  59.global kvm_template_start
  60kvm_template_start:
  61
  62.global kvm_emulate_mtmsrd
  63kvm_emulate_mtmsrd:
  64
  65        SCRATCH_SAVE
  66
  67        /* Put MSR & ~(MSR_EE|MSR_RI) in r31 */
  68        LL64(r31, KVM_MAGIC_PAGE + KVM_MAGIC_MSR, 0)
  69        lis     r30, (~(MSR_EE | MSR_RI))@h
  70        ori     r30, r30, (~(MSR_EE | MSR_RI))@l
  71        and     r31, r31, r30
  72
  73        /* OR the register's (MSR_EE|MSR_RI) on MSR */
  74kvm_emulate_mtmsrd_reg:
  75        ori     r30, r0, 0
  76        andi.   r30, r30, (MSR_EE|MSR_RI)
  77        or      r31, r31, r30
  78
  79        /* Put MSR back into magic page */
  80        STL64(r31, KVM_MAGIC_PAGE + KVM_MAGIC_MSR, 0)
  81
  82        /* Check if we have to fetch an interrupt */
  83        lwz     r31, (KVM_MAGIC_PAGE + KVM_MAGIC_INT)(0)
  84        cmpwi   r31, 0
  85        beq+    no_check
  86
  87        /* Check if we may trigger an interrupt */
  88        andi.   r30, r30, MSR_EE
  89        beq     no_check
  90
  91        SCRATCH_RESTORE
  92
  93        /* Nag hypervisor */
  94kvm_emulate_mtmsrd_orig_ins:
  95        tlbsync
  96
  97        b       kvm_emulate_mtmsrd_branch
  98
  99no_check:
 100
 101        SCRATCH_RESTORE
 102
 103        /* Go back to caller */
 104kvm_emulate_mtmsrd_branch:
 105        b       .
 106kvm_emulate_mtmsrd_end:
 107
 108.global kvm_emulate_mtmsrd_branch_offs
 109kvm_emulate_mtmsrd_branch_offs:
 110        .long (kvm_emulate_mtmsrd_branch - kvm_emulate_mtmsrd) / 4
 111
 112.global kvm_emulate_mtmsrd_reg_offs
 113kvm_emulate_mtmsrd_reg_offs:
 114        .long (kvm_emulate_mtmsrd_reg - kvm_emulate_mtmsrd) / 4
 115
 116.global kvm_emulate_mtmsrd_orig_ins_offs
 117kvm_emulate_mtmsrd_orig_ins_offs:
 118        .long (kvm_emulate_mtmsrd_orig_ins - kvm_emulate_mtmsrd) / 4
 119
 120.global kvm_emulate_mtmsrd_len
 121kvm_emulate_mtmsrd_len:
 122        .long (kvm_emulate_mtmsrd_end - kvm_emulate_mtmsrd) / 4
 123
 124
 125#define MSR_SAFE_BITS (MSR_EE | MSR_RI)
 126#define MSR_CRITICAL_BITS ~MSR_SAFE_BITS
 127
 128.global kvm_emulate_mtmsr
 129kvm_emulate_mtmsr:
 130
 131        SCRATCH_SAVE
 132
 133        /* Fetch old MSR in r31 */
 134        LL64(r31, KVM_MAGIC_PAGE + KVM_MAGIC_MSR, 0)
 135
 136        /* Find the changed bits between old and new MSR */
 137kvm_emulate_mtmsr_reg1:
 138        ori     r30, r0, 0
 139        xor     r31, r30, r31
 140
 141        /* Check if we need to really do mtmsr */
 142        LOAD_REG_IMMEDIATE(r30, MSR_CRITICAL_BITS)
 143        and.    r31, r31, r30
 144
 145        /* No critical bits changed? Maybe we can stay in the guest. */
 146        beq     maybe_stay_in_guest
 147
 148do_mtmsr:
 149
 150        SCRATCH_RESTORE
 151
 152        /* Just fire off the mtmsr if it's critical */
 153kvm_emulate_mtmsr_orig_ins:
 154        mtmsr   r0
 155
 156        b       kvm_emulate_mtmsr_branch
 157
 158maybe_stay_in_guest:
 159
 160        /* Get the target register in r30 */
 161kvm_emulate_mtmsr_reg2:
 162        ori     r30, r0, 0
 163
 164        /* Put MSR into magic page because we don't call mtmsr */
 165        STL64(r30, KVM_MAGIC_PAGE + KVM_MAGIC_MSR, 0)
 166
 167        /* Check if we have to fetch an interrupt */
 168        lwz     r31, (KVM_MAGIC_PAGE + KVM_MAGIC_INT)(0)
 169        cmpwi   r31, 0
 170        beq+    no_mtmsr
 171
 172        /* Check if we may trigger an interrupt */
 173        andi.   r31, r30, MSR_EE
 174        bne     do_mtmsr
 175
 176no_mtmsr:
 177
 178        SCRATCH_RESTORE
 179
 180        /* Go back to caller */
 181kvm_emulate_mtmsr_branch:
 182        b       .
 183kvm_emulate_mtmsr_end:
 184
 185.global kvm_emulate_mtmsr_branch_offs
 186kvm_emulate_mtmsr_branch_offs:
 187        .long (kvm_emulate_mtmsr_branch - kvm_emulate_mtmsr) / 4
 188
 189.global kvm_emulate_mtmsr_reg1_offs
 190kvm_emulate_mtmsr_reg1_offs:
 191        .long (kvm_emulate_mtmsr_reg1 - kvm_emulate_mtmsr) / 4
 192
 193.global kvm_emulate_mtmsr_reg2_offs
 194kvm_emulate_mtmsr_reg2_offs:
 195        .long (kvm_emulate_mtmsr_reg2 - kvm_emulate_mtmsr) / 4
 196
 197.global kvm_emulate_mtmsr_orig_ins_offs
 198kvm_emulate_mtmsr_orig_ins_offs:
 199        .long (kvm_emulate_mtmsr_orig_ins - kvm_emulate_mtmsr) / 4
 200
 201.global kvm_emulate_mtmsr_len
 202kvm_emulate_mtmsr_len:
 203        .long (kvm_emulate_mtmsr_end - kvm_emulate_mtmsr) / 4
 204
 205/* also used for wrteei 1 */
 206.global kvm_emulate_wrtee
 207kvm_emulate_wrtee:
 208
 209        SCRATCH_SAVE
 210
 211        /* Fetch old MSR in r31 */
 212        LL64(r31, KVM_MAGIC_PAGE + KVM_MAGIC_MSR, 0)
 213
 214        /* Insert new MSR[EE] */
 215kvm_emulate_wrtee_reg:
 216        ori     r30, r0, 0
 217        rlwimi  r31, r30, 0, MSR_EE
 218
 219        /*
 220         * If MSR[EE] is now set, check for a pending interrupt.
 221         * We could skip this if MSR[EE] was already on, but that
 222         * should be rare, so don't bother.
 223         */
 224        andi.   r30, r30, MSR_EE
 225
 226        /* Put MSR into magic page because we don't call wrtee */
 227        STL64(r31, KVM_MAGIC_PAGE + KVM_MAGIC_MSR, 0)
 228
 229        beq     no_wrtee
 230
 231        /* Check if we have to fetch an interrupt */
 232        lwz     r30, (KVM_MAGIC_PAGE + KVM_MAGIC_INT)(0)
 233        cmpwi   r30, 0
 234        bne     do_wrtee
 235
 236no_wrtee:
 237        SCRATCH_RESTORE
 238
 239        /* Go back to caller */
 240kvm_emulate_wrtee_branch:
 241        b       .
 242
 243do_wrtee:
 244        SCRATCH_RESTORE
 245
 246        /* Just fire off the wrtee if it's critical */
 247kvm_emulate_wrtee_orig_ins:
 248        wrtee   r0
 249
 250        b       kvm_emulate_wrtee_branch
 251
 252kvm_emulate_wrtee_end:
 253
 254.global kvm_emulate_wrtee_branch_offs
 255kvm_emulate_wrtee_branch_offs:
 256        .long (kvm_emulate_wrtee_branch - kvm_emulate_wrtee) / 4
 257
 258.global kvm_emulate_wrtee_reg_offs
 259kvm_emulate_wrtee_reg_offs:
 260        .long (kvm_emulate_wrtee_reg - kvm_emulate_wrtee) / 4
 261
 262.global kvm_emulate_wrtee_orig_ins_offs
 263kvm_emulate_wrtee_orig_ins_offs:
 264        .long (kvm_emulate_wrtee_orig_ins - kvm_emulate_wrtee) / 4
 265
 266.global kvm_emulate_wrtee_len
 267kvm_emulate_wrtee_len:
 268        .long (kvm_emulate_wrtee_end - kvm_emulate_wrtee) / 4
 269
 270.global kvm_emulate_wrteei_0
 271kvm_emulate_wrteei_0:
 272        SCRATCH_SAVE
 273
 274        /* Fetch old MSR in r31 */
 275        LL64(r31, KVM_MAGIC_PAGE + KVM_MAGIC_MSR, 0)
 276
 277        /* Remove MSR_EE from old MSR */
 278        rlwinm  r31, r31, 0, ~MSR_EE
 279
 280        /* Write new MSR value back */
 281        STL64(r31, KVM_MAGIC_PAGE + KVM_MAGIC_MSR, 0)
 282
 283        SCRATCH_RESTORE
 284
 285        /* Go back to caller */
 286kvm_emulate_wrteei_0_branch:
 287        b       .
 288kvm_emulate_wrteei_0_end:
 289
 290.global kvm_emulate_wrteei_0_branch_offs
 291kvm_emulate_wrteei_0_branch_offs:
 292        .long (kvm_emulate_wrteei_0_branch - kvm_emulate_wrteei_0) / 4
 293
 294.global kvm_emulate_wrteei_0_len
 295kvm_emulate_wrteei_0_len:
 296        .long (kvm_emulate_wrteei_0_end - kvm_emulate_wrteei_0) / 4
 297
 298.global kvm_emulate_mtsrin
 299kvm_emulate_mtsrin:
 300
 301        SCRATCH_SAVE
 302
 303        LL64(r31, KVM_MAGIC_PAGE + KVM_MAGIC_MSR, 0)
 304        andi.   r31, r31, MSR_DR | MSR_IR
 305        beq     kvm_emulate_mtsrin_reg1
 306
 307        SCRATCH_RESTORE
 308
 309kvm_emulate_mtsrin_orig_ins:
 310        nop
 311        b       kvm_emulate_mtsrin_branch
 312
 313kvm_emulate_mtsrin_reg1:
 314        /* rX >> 26 */
 315        rlwinm  r30,r0,6,26,29
 316
 317kvm_emulate_mtsrin_reg2:
 318        stw     r0, (KVM_MAGIC_PAGE + KVM_MAGIC_SR)(r30)
 319
 320        SCRATCH_RESTORE
 321
 322        /* Go back to caller */
 323kvm_emulate_mtsrin_branch:
 324        b       .
 325kvm_emulate_mtsrin_end:
 326
 327.global kvm_emulate_mtsrin_branch_offs
 328kvm_emulate_mtsrin_branch_offs:
 329        .long (kvm_emulate_mtsrin_branch - kvm_emulate_mtsrin) / 4
 330
 331.global kvm_emulate_mtsrin_reg1_offs
 332kvm_emulate_mtsrin_reg1_offs:
 333        .long (kvm_emulate_mtsrin_reg1 - kvm_emulate_mtsrin) / 4
 334
 335.global kvm_emulate_mtsrin_reg2_offs
 336kvm_emulate_mtsrin_reg2_offs:
 337        .long (kvm_emulate_mtsrin_reg2 - kvm_emulate_mtsrin) / 4
 338
 339.global kvm_emulate_mtsrin_orig_ins_offs
 340kvm_emulate_mtsrin_orig_ins_offs:
 341        .long (kvm_emulate_mtsrin_orig_ins - kvm_emulate_mtsrin) / 4
 342
 343.global kvm_emulate_mtsrin_len
 344kvm_emulate_mtsrin_len:
 345        .long (kvm_emulate_mtsrin_end - kvm_emulate_mtsrin) / 4
 346
 347.global kvm_template_end
 348kvm_template_end:
 349