arch/powerpc/kvm/book3s_interrupts.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 #include <asm/ppc_asm.h>
  21 #include <asm/kvm_asm.h>
  22 #include <asm/reg.h>
  23 #include <asm/page.h>
  24 #include <asm/asm-offsets.h>
  25 #include <asm/exception-64s.h>
  26
  27 #if defined(CONFIG_PPC_BOOK3S_64)
  28 #if defined(_CALL_ELF) && _CALL_ELF == 2
  29 #define FUNC(name)              name
  30 #else
  31 #define FUNC(name)              GLUE(.,name)
  32 #endif
  33 #define GET_SHADOW_VCPU(reg)    addi    reg, r13, PACA_SVCPU
  34
  35 #elif defined(CONFIG_PPC_BOOK3S_32)
  36 #define FUNC(name)              name
  37 #define GET_SHADOW_VCPU(reg)    lwz     reg, (THREAD + THREAD_KVM_SVCPU)(r2)
  38
  39 #endif /* CONFIG_PPC_BOOK3S_XX */
  40
  41 #define VCPU_LOAD_NVGPRS(vcpu) \
  42         PPC_LL  r14, VCPU_GPR(R14)(vcpu); \
  43         PPC_LL  r15, VCPU_GPR(R15)(vcpu); \
  44         PPC_LL  r16, VCPU_GPR(R16)(vcpu); \
  45         PPC_LL  r17, VCPU_GPR(R17)(vcpu); \
  46         PPC_LL  r18, VCPU_GPR(R18)(vcpu); \
  47         PPC_LL  r19, VCPU_GPR(R19)(vcpu); \
  48         PPC_LL  r20, VCPU_GPR(R20)(vcpu); \
  49         PPC_LL  r21, VCPU_GPR(R21)(vcpu); \
  50         PPC_LL  r22, VCPU_GPR(R22)(vcpu); \
  51         PPC_LL  r23, VCPU_GPR(R23)(vcpu); \
  52         PPC_LL  r24, VCPU_GPR(R24)(vcpu); \
  53         PPC_LL  r25, VCPU_GPR(R25)(vcpu); \
  54         PPC_LL  r26, VCPU_GPR(R26)(vcpu); \
  55         PPC_LL  r27, VCPU_GPR(R27)(vcpu); \
  56         PPC_LL  r28, VCPU_GPR(R28)(vcpu); \
  57         PPC_LL  r29, VCPU_GPR(R29)(vcpu); \
  58         PPC_LL  r30, VCPU_GPR(R30)(vcpu); \
  59         PPC_LL  r31, VCPU_GPR(R31)(vcpu); \
  60
  61 /*****************************************************************************
  62  *                                                                           *
  63  *     Guest entry / exit code that is in kernel module memory (highmem)     *
  64  *                                                                           *
  65  ****************************************************************************/
  66
  67 /* Registers:
  68  *  r3: kvm_run pointer
  69  *  r4: vcpu pointer
  70  */
  71 _GLOBAL(__kvmppc_vcpu_run)
  72
  73 kvm_start_entry:
  74         /* Write correct stack frame */
  75         mflr    r0
  76         PPC_STL r0,PPC_LR_STKOFF(r1)
  77
  78         /* Save host state to the stack */
  79         PPC_STLU r1, -SWITCH_FRAME_SIZE(r1)
  80
  81         /* Save r3 (kvm_run) and r4 (vcpu) */
  82         SAVE_2GPRS(3, r1)
  83
  84         /* Save non-volatile registers (r14 - r31) */
  85         SAVE_NVGPRS(r1)
  86
  87         /* Save CR */
  88         mfcr    r14
  89         stw     r14, _CCR(r1)
  90
  91         /* Save LR */
  92         PPC_STL r0, _LINK(r1)
  93
  94         /* Load non-volatile guest state from the vcpu */
  95         VCPU_LOAD_NVGPRS(r4)
  96
  97 kvm_start_lightweight:
  98         /* Copy registers into shadow vcpu so we can access them in real mode */
  99         GET_SHADOW_VCPU(r3)
 100         bl      FUNC(kvmppc_copy_to_svcpu)
 101         nop
 102         REST_GPR(4, r1)
 103
 104 #ifdef CONFIG_PPC_BOOK3S_64
 105         /* Get the dcbz32 flag */
 106         PPC_LL  r3, VCPU_HFLAGS(r4)
 107         rldicl  r3, r3, 0, 63           /* r3 &= 1 */
 108         stb     r3, HSTATE_RESTORE_HID5(r13)
 109
 110         /* Load up guest SPRG3 value, since it's user readable */
 111         lwz     r3, VCPU_SHAREDBE(r4)
 112         cmpwi   r3, 0
 113         ld      r5, VCPU_SHARED(r4)
 114         beq     sprg3_little_endian
 115 sprg3_big_endian:
 116 #ifdef __BIG_ENDIAN__
 117         ld      r3, VCPU_SHARED_SPRG3(r5)
 118 #else
 119         addi    r5, r5, VCPU_SHARED_SPRG3
 120         ldbrx   r3, 0, r5
 121 #endif
 122         b       after_sprg3_load
 123 sprg3_little_endian:
 124 #ifdef __LITTLE_ENDIAN__
 125         ld      r3, VCPU_SHARED_SPRG3(r5)
 126 #else
 127         addi    r5, r5, VCPU_SHARED_SPRG3
 128         ldbrx   r3, 0, r5
 129 #endif
 130
 131 after_sprg3_load:
 132         mtspr   SPRN_SPRG3, r3
 133 #endif /* CONFIG_PPC_BOOK3S_64 */
 134
 135         PPC_LL  r4, VCPU_SHADOW_MSR(r4) /* get shadow_msr */
 136
 137         /* Jump to segment patching handler and into our guest */
 138         bl      FUNC(kvmppc_entry_trampoline)
 139         nop
 140
 141 /*
 142  * This is the handler in module memory. It gets jumped at from the
 143  * lowmem trampoline code, so it's basically the guest exit code.
 144  *
 145  */
 146
 147         /*
 148          * Register usage at this point:
 149          *
 150          * R1       = host R1
 151          * R2       = host R2
 152          * R12      = exit handler id
 153          * R13      = PACA
 154          * SVCPU.*  = guest *
 155          * MSR.EE   = 1
 156          *
 157          */
 158
 159         PPC_LL  r3, GPR4(r1)            /* vcpu pointer */
 160
 161         /*
 162          * kvmppc_copy_from_svcpu can clobber volatile registers, save
 163          * the exit handler id to the vcpu and restore it from there later.
 164          */
 165         stw     r12, VCPU_TRAP(r3)
 166
 167         /* Transfer reg values from shadow vcpu back to vcpu struct */
 168         /* On 64-bit, interrupts are still off at this point */
 169
 170         GET_SHADOW_VCPU(r4)
 171         bl      FUNC(kvmppc_copy_from_svcpu)
 172         nop
 173
 174 #ifdef CONFIG_PPC_BOOK3S_64
 175         /*
 176          * Reload kernel SPRG3 value.
 177          * No need to save guest value as usermode can't modify SPRG3.
 178          */
 179         ld      r3, PACA_SPRG_VDSO(r13)
 180         mtspr   SPRN_SPRG_VDSO_WRITE, r3
 181 #endif /* CONFIG_PPC_BOOK3S_64 */
 182
 183         /* R7 = vcpu */
 184         PPC_LL  r7, GPR4(r1)
 185
 186         PPC_STL r14, VCPU_GPR(R14)(r7)
 187         PPC_STL r15, VCPU_GPR(R15)(r7)
 188         PPC_STL r16, VCPU_GPR(R16)(r7)
 189         PPC_STL r17, VCPU_GPR(R17)(r7)
 190         PPC_STL r18, VCPU_GPR(R18)(r7)
 191         PPC_STL r19, VCPU_GPR(R19)(r7)
 192         PPC_STL r20, VCPU_GPR(R20)(r7)
 193         PPC_STL r21, VCPU_GPR(R21)(r7)
 194         PPC_STL r22, VCPU_GPR(R22)(r7)
 195         PPC_STL r23, VCPU_GPR(R23)(r7)
 196         PPC_STL r24, VCPU_GPR(R24)(r7)
 197         PPC_STL r25, VCPU_GPR(R25)(r7)
 198         PPC_STL r26, VCPU_GPR(R26)(r7)
 199         PPC_STL r27, VCPU_GPR(R27)(r7)
 200         PPC_STL r28, VCPU_GPR(R28)(r7)
 201         PPC_STL r29, VCPU_GPR(R29)(r7)
 202         PPC_STL r30, VCPU_GPR(R30)(r7)
 203         PPC_STL r31, VCPU_GPR(R31)(r7)
 204
 205         /* Pass the exit number as 3rd argument to kvmppc_handle_exit */
 206         lwz     r5, VCPU_TRAP(r7)
 207
 208         /* Restore r3 (kvm_run) and r4 (vcpu) */
 209         REST_2GPRS(3, r1)
 210         bl      FUNC(kvmppc_handle_exit_pr)
 211
 212         /* If RESUME_GUEST, get back in the loop */
 213         cmpwi   r3, RESUME_GUEST
 214         beq     kvm_loop_lightweight
 215
 216         cmpwi   r3, RESUME_GUEST_NV
 217         beq     kvm_loop_heavyweight
 218
 219 kvm_exit_loop:
 220
 221         PPC_LL  r4, _LINK(r1)
 222         mtlr    r4
 223
 224         lwz     r14, _CCR(r1)
 225         mtcr    r14
 226
 227         /* Restore non-volatile host registers (r14 - r31) */
 228         REST_NVGPRS(r1)
 229
 230         addi    r1, r1, SWITCH_FRAME_SIZE
 231         blr
 232
 233 kvm_loop_heavyweight:
 234
 235         PPC_LL  r4, _LINK(r1)
 236         PPC_STL r4, (PPC_LR_STKOFF + SWITCH_FRAME_SIZE)(r1)
 237
 238         /* Load vcpu and cpu_run */
 239         REST_2GPRS(3, r1)
 240
 241         /* Load non-volatile guest state from the vcpu */
 242         VCPU_LOAD_NVGPRS(r4)
 243
 244         /* Jump back into the beginning of this function */
 245         b       kvm_start_lightweight
 246
 247 kvm_loop_lightweight:
 248
 249         /* We'll need the vcpu pointer */
 250         REST_GPR(4, r1)
 251
 252         /* Jump back into the beginning of this function */
 253         b       kvm_start_lightweight