arch/powerpc/kvm/book3s_interrupts.S

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2 /*
   3  *
   4  * Copyright SUSE Linux Products GmbH 2009
   5  *
   6  * Authors: Alexander Graf <agraf@suse.de>
   7  */
   8
   9 #include <asm/ppc_asm.h>
  10 #include <asm/kvm_asm.h>
  11 #include <asm/reg.h>
  12 #include <asm/page.h>
  13 #include <asm/asm-offsets.h>
  14 #include <asm/exception-64s.h>
  15 #include <asm/asm-compat.h>
  16
  17 #if defined(CONFIG_PPC_BOOK3S_64)
  18 #ifdef PPC64_ELF_ABI_v2
  19 #define FUNC(name)              name
  20 #else
  21 #define FUNC(name)              GLUE(.,name)
  22 #endif
  23 #define GET_SHADOW_VCPU(reg)    addi    reg, r13, PACA_SVCPU
  24
  25 #elif defined(CONFIG_PPC_BOOK3S_32)
  26 #define FUNC(name)              name
  27 #define GET_SHADOW_VCPU(reg)    lwz     reg, (THREAD + THREAD_KVM_SVCPU)(r2)
  28
  29 #endif /* CONFIG_PPC_BOOK3S_64 */
  30
  31 #define VCPU_LOAD_NVGPRS(vcpu) \
  32         PPC_LL  r14, VCPU_GPR(R14)(vcpu); \
  33         PPC_LL  r15, VCPU_GPR(R15)(vcpu); \
  34         PPC_LL  r16, VCPU_GPR(R16)(vcpu); \
  35         PPC_LL  r17, VCPU_GPR(R17)(vcpu); \
  36         PPC_LL  r18, VCPU_GPR(R18)(vcpu); \
  37         PPC_LL  r19, VCPU_GPR(R19)(vcpu); \
  38         PPC_LL  r20, VCPU_GPR(R20)(vcpu); \
  39         PPC_LL  r21, VCPU_GPR(R21)(vcpu); \
  40         PPC_LL  r22, VCPU_GPR(R22)(vcpu); \
  41         PPC_LL  r23, VCPU_GPR(R23)(vcpu); \
  42         PPC_LL  r24, VCPU_GPR(R24)(vcpu); \
  43         PPC_LL  r25, VCPU_GPR(R25)(vcpu); \
  44         PPC_LL  r26, VCPU_GPR(R26)(vcpu); \
  45         PPC_LL  r27, VCPU_GPR(R27)(vcpu); \
  46         PPC_LL  r28, VCPU_GPR(R28)(vcpu); \
  47         PPC_LL  r29, VCPU_GPR(R29)(vcpu); \
  48         PPC_LL  r30, VCPU_GPR(R30)(vcpu); \
  49         PPC_LL  r31, VCPU_GPR(R31)(vcpu); \
  50
  51 /*****************************************************************************
  52  *                                                                           *
  53  *     Guest entry / exit code that is in kernel module memory (highmem)     *
  54  *                                                                           *
  55  ****************************************************************************/
  56
  57 /* Registers:
  58  *  r3: vcpu pointer
  59  */
  60 _GLOBAL(__kvmppc_vcpu_run)
  61
  62 kvm_start_entry:
  63         /* Write correct stack frame */
  64         mflr    r0
  65         PPC_STL r0,PPC_LR_STKOFF(r1)
  66
  67         /* Save host state to the stack */
  68         PPC_STLU r1, -SWITCH_FRAME_SIZE(r1)
  69
  70         /* Save r3 (vcpu) */
  71         SAVE_GPR(3, r1)
  72
  73         /* Save non-volatile registers (r14 - r31) */
  74         SAVE_NVGPRS(r1)
  75
  76         /* Save CR */
  77         mfcr    r14
  78         stw     r14, _CCR(r1)
  79
  80         /* Save LR */
  81         PPC_STL r0, _LINK(r1)
  82
  83         /* Load non-volatile guest state from the vcpu */
  84         VCPU_LOAD_NVGPRS(r3)
  85
  86 kvm_start_lightweight:
  87         /* Copy registers into shadow vcpu so we can access them in real mode */
  88         bl      FUNC(kvmppc_copy_to_svcpu)
  89         nop
  90         REST_GPR(3, r1)
  91
  92 #ifdef CONFIG_PPC_BOOK3S_64
  93         /* Get the dcbz32 flag */
  94         PPC_LL  r0, VCPU_HFLAGS(r3)
  95         rldicl  r0, r0, 0, 63           /* r3 &= 1 */
  96         stb     r0, HSTATE_RESTORE_HID5(r13)
  97
  98         /* Load up guest SPRG3 value, since it's user readable */
  99         lbz     r4, VCPU_SHAREDBE(r3)
 100         cmpwi   r4, 0
 101         ld      r5, VCPU_SHARED(r3)
 102         beq     sprg3_little_endian
 103 sprg3_big_endian:
 104 #ifdef __BIG_ENDIAN__
 105         ld      r4, VCPU_SHARED_SPRG3(r5)
 106 #else
 107         addi    r5, r5, VCPU_SHARED_SPRG3
 108         ldbrx   r4, 0, r5
 109 #endif
 110         b       after_sprg3_load
 111 sprg3_little_endian:
 112 #ifdef __LITTLE_ENDIAN__
 113         ld      r4, VCPU_SHARED_SPRG3(r5)
 114 #else
 115         addi    r5, r5, VCPU_SHARED_SPRG3
 116         ldbrx   r4, 0, r5
 117 #endif
 118
 119 after_sprg3_load:
 120         mtspr   SPRN_SPRG3, r4
 121 #endif /* CONFIG_PPC_BOOK3S_64 */
 122
 123         PPC_LL  r4, VCPU_SHADOW_MSR(r3) /* get shadow_msr */
 124
 125         /* Jump to segment patching handler and into our guest */
 126         bl      FUNC(kvmppc_entry_trampoline)
 127         nop
 128
 129 /*
 130  * This is the handler in module memory. It gets jumped at from the
 131  * lowmem trampoline code, so it's basically the guest exit code.
 132  *
 133  */
 134
 135         /*
 136          * Register usage at this point:
 137          *
 138          * R1       = host R1
 139          * R2       = host R2
 140          * R12      = exit handler id
 141          * R13      = PACA
 142          * SVCPU.*  = guest *
 143          * MSR.EE   = 1
 144          *
 145          */
 146
 147         PPC_LL  r3, GPR3(r1)            /* vcpu pointer */
 148
 149         /*
 150          * kvmppc_copy_from_svcpu can clobber volatile registers, save
 151          * the exit handler id to the vcpu and restore it from there later.
 152          */
 153         stw     r12, VCPU_TRAP(r3)
 154
 155         /* Transfer reg values from shadow vcpu back to vcpu struct */
 156
 157         bl      FUNC(kvmppc_copy_from_svcpu)
 158         nop
 159
 160 #ifdef CONFIG_PPC_BOOK3S_64
 161         /*
 162          * Reload kernel SPRG3 value.
 163          * No need to save guest value as usermode can't modify SPRG3.
 164          */
 165         ld      r3, PACA_SPRG_VDSO(r13)
 166         mtspr   SPRN_SPRG_VDSO_WRITE, r3
 167 #endif /* CONFIG_PPC_BOOK3S_64 */
 168
 169         /* R7 = vcpu */
 170         PPC_LL  r7, GPR3(r1)
 171
 172         PPC_STL r14, VCPU_GPR(R14)(r7)
 173         PPC_STL r15, VCPU_GPR(R15)(r7)
 174         PPC_STL r16, VCPU_GPR(R16)(r7)
 175         PPC_STL r17, VCPU_GPR(R17)(r7)
 176         PPC_STL r18, VCPU_GPR(R18)(r7)
 177         PPC_STL r19, VCPU_GPR(R19)(r7)
 178         PPC_STL r20, VCPU_GPR(R20)(r7)
 179         PPC_STL r21, VCPU_GPR(R21)(r7)
 180         PPC_STL r22, VCPU_GPR(R22)(r7)
 181         PPC_STL r23, VCPU_GPR(R23)(r7)
 182         PPC_STL r24, VCPU_GPR(R24)(r7)
 183         PPC_STL r25, VCPU_GPR(R25)(r7)
 184         PPC_STL r26, VCPU_GPR(R26)(r7)
 185         PPC_STL r27, VCPU_GPR(R27)(r7)
 186         PPC_STL r28, VCPU_GPR(R28)(r7)
 187         PPC_STL r29, VCPU_GPR(R29)(r7)
 188         PPC_STL r30, VCPU_GPR(R30)(r7)
 189         PPC_STL r31, VCPU_GPR(R31)(r7)
 190
 191         /* Pass the exit number as 2nd argument to kvmppc_handle_exit */
 192         lwz     r4, VCPU_TRAP(r7)
 193
 194         /* Restore r3 (vcpu) */
 195         REST_GPR(3, r1)
 196         bl      FUNC(kvmppc_handle_exit_pr)
 197
 198         /* If RESUME_GUEST, get back in the loop */
 199         cmpwi   r3, RESUME_GUEST
 200         beq     kvm_loop_lightweight
 201
 202         cmpwi   r3, RESUME_GUEST_NV
 203         beq     kvm_loop_heavyweight
 204
 205 kvm_exit_loop:
 206
 207         PPC_LL  r4, _LINK(r1)
 208         mtlr    r4
 209
 210         lwz     r14, _CCR(r1)
 211         mtcr    r14
 212
 213         /* Restore non-volatile host registers (r14 - r31) */
 214         REST_NVGPRS(r1)
 215
 216         addi    r1, r1, SWITCH_FRAME_SIZE
 217         blr
 218
 219 kvm_loop_heavyweight:
 220
 221         PPC_LL  r4, _LINK(r1)
 222         PPC_STL r4, (PPC_LR_STKOFF + SWITCH_FRAME_SIZE)(r1)
 223
 224         /* Load vcpu */
 225         REST_GPR(3, r1)
 226
 227         /* Load non-volatile guest state from the vcpu */
 228         VCPU_LOAD_NVGPRS(r3)
 229
 230         /* Jump back into the beginning of this function */
 231         b       kvm_start_lightweight
 232
 233 kvm_loop_lightweight:
 234
 235         /* We'll need the vcpu pointer */
 236         REST_GPR(3, r1)
 237
 238         /* Jump back into the beginning of this function */
 239         b       kvm_start_lightweight