powerpc/kvm/book3s_rmhandlers.S

0001 /* SPDX-License-Identifier: GPL-2.0-only */
0002 /*
0003  *
0004  * Copyright SUSE Linux Products GmbH 2009
0005  *
0006  * Authors: Alexander Graf <agraf@suse.de>
0007  */
0008
0009 #include <asm/ppc_asm.h>
0010 #include <asm/kvm_asm.h>
0011 #include <asm/reg.h>
0012 #include <asm/mmu.h>
0013 #include <asm/page.h>
0014 #include <asm/asm-offsets.h>
0015 #include <asm/asm-compat.h>
0016
0017 #ifdef CONFIG_PPC_BOOK3S_64
0018 #include <asm/exception-64s.h>
0019 #endif
0020
0021 /*****************************************************************************
0022  *                                                                           *
0023  *        Real Mode handlers that need to be in low physical memory          *
0024  *                                                                           *
0025  ****************************************************************************/
0026
0027 #if defined(CONFIG_PPC_BOOK3S_64)
0028
0029 #ifdef CONFIG_PPC64_ELF_ABI_V2
0030 #define FUNC(name)      name
0031 #else
0032 #define FUNC(name)      GLUE(.,name)
0033 #endif
0034
0035 #elif defined(CONFIG_PPC_BOOK3S_32)
0036
0037 #define FUNC(name)      name
0038
0039 #define RFI_TO_KERNEL   rfi
0040 #define RFI_TO_GUEST    rfi
0041
0042 .macro INTERRUPT_TRAMPOLINE intno
0043
0044 .global kvmppc_trampoline_\intno
0045 kvmppc_trampoline_\intno:
0046
0047     mtspr   SPRN_SPRG_SCRATCH0, r13     /* Save r13 */
0048
0049     /*
0050      * First thing to do is to find out if we're coming
0051      * from a KVM guest or a Linux process.
0052      *
0053      * To distinguish, we check a magic byte in the PACA/current
0054      */
0055     mfspr   r13, SPRN_SPRG_THREAD
0056     lwz r13, THREAD_KVM_SVCPU(r13)
0057     /* PPC32 can have a NULL pointer - let's check for that */
0058     mtspr   SPRN_SPRG_SCRATCH1, r12     /* Save r12 */
0059     mfcr    r12
0060     cmpwi   r13, 0
0061     bne 1f
0062 2:  mtcr    r12
0063     mfspr   r12, SPRN_SPRG_SCRATCH1
0064     mfspr   r13, SPRN_SPRG_SCRATCH0     /* r13 = original r13 */
0065     b   kvmppc_resume_\intno        /* Get back original handler */
0066
0067 1:  tophys(r13, r13)
0068     stw r12, HSTATE_SCRATCH1(r13)
0069     mfspr   r12, SPRN_SPRG_SCRATCH1
0070     stw r12, HSTATE_SCRATCH0(r13)
0071     lbz r12, HSTATE_IN_GUEST(r13)
0072     cmpwi   r12, KVM_GUEST_MODE_NONE
0073     bne ..kvmppc_handler_hasmagic_\intno
0074     /* No KVM guest? Then jump back to the Linux handler! */
0075     lwz r12, HSTATE_SCRATCH1(r13)
0076     b   2b
0077
0078     /* Now we know we're handling a KVM guest */
0079 ..kvmppc_handler_hasmagic_\intno:
0080
0081     /* Should we just skip the faulting instruction? */
0082     cmpwi   r12, KVM_GUEST_MODE_SKIP
0083     beq kvmppc_handler_skip_ins
0084
0085     /* Let's store which interrupt we're handling */
0086     li  r12, \intno
0087
0088     /* Jump into the SLB exit code that goes to the highmem handler */
0089     b   kvmppc_handler_trampoline_exit
0090
0091 .endm
0092
0093 INTERRUPT_TRAMPOLINE    BOOK3S_INTERRUPT_SYSTEM_RESET
0094 INTERRUPT_TRAMPOLINE    BOOK3S_INTERRUPT_MACHINE_CHECK
0095 INTERRUPT_TRAMPOLINE    BOOK3S_INTERRUPT_DATA_STORAGE
0096 INTERRUPT_TRAMPOLINE    BOOK3S_INTERRUPT_INST_STORAGE
0097 INTERRUPT_TRAMPOLINE    BOOK3S_INTERRUPT_EXTERNAL
0098 INTERRUPT_TRAMPOLINE    BOOK3S_INTERRUPT_ALIGNMENT
0099 INTERRUPT_TRAMPOLINE    BOOK3S_INTERRUPT_PROGRAM
0100 INTERRUPT_TRAMPOLINE    BOOK3S_INTERRUPT_FP_UNAVAIL
0101 INTERRUPT_TRAMPOLINE    BOOK3S_INTERRUPT_DECREMENTER
0102 INTERRUPT_TRAMPOLINE    BOOK3S_INTERRUPT_SYSCALL
0103 INTERRUPT_TRAMPOLINE    BOOK3S_INTERRUPT_TRACE
0104 INTERRUPT_TRAMPOLINE    BOOK3S_INTERRUPT_PERFMON
0105 INTERRUPT_TRAMPOLINE    BOOK3S_INTERRUPT_ALTIVEC
0106
0107 /*
0108  * Bring us back to the faulting code, but skip the
0109  * faulting instruction.
0110  *
0111  * This is a generic exit path from the interrupt
0112  * trampolines above.
0113  *
0114  * Input Registers:
0115  *
0116  * R12            = free
0117  * R13            = Shadow VCPU (PACA)
0118  * HSTATE.SCRATCH0 = guest R12
0119  * HSTATE.SCRATCH1 = guest CR
0120  * SPRG_SCRATCH0  = guest R13
0121  *
0122  */
0123 kvmppc_handler_skip_ins:
0124
0125     /* Patch the IP to the next instruction */
0126     mfsrr0  r12
0127     addi    r12, r12, 4
0128     mtsrr0  r12
0129
0130     /* Clean up all state */
0131     lwz r12, HSTATE_SCRATCH1(r13)
0132     mtcr    r12
0133     PPC_LL  r12, HSTATE_SCRATCH0(r13)
0134     GET_SCRATCH0(r13)
0135
0136     /* And get back into the code */
0137     RFI_TO_KERNEL
0138 #endif
0139
0140 /*
0141  * Call kvmppc_handler_trampoline_enter in real mode
0142  *
0143  * On entry, r4 contains the guest shadow MSR
0144  * MSR.EE has to be 0 when calling this function
0145  */
0146 _GLOBAL_TOC(kvmppc_entry_trampoline)
0147     mfmsr   r5
0148     LOAD_REG_ADDR(r7, kvmppc_handler_trampoline_enter)
0149     toreal(r7)
0150
0151     li  r6, MSR_IR | MSR_DR
0152     andc    r6, r5, r6  /* Clear DR and IR in MSR value */
0153     /*
0154      * Set EE in HOST_MSR so that it's enabled when we get into our
0155      * C exit handler function.
0156      */
0157     ori r5, r5, MSR_EE
0158     mtsrr0  r7
0159     mtsrr1  r6
0160     RFI_TO_KERNEL
0161
0162 #include "book3s_segment.S"