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-rw-r--r--arch/powerpc/kvm/book3s_segment.S409
1 files changed, 409 insertions, 0 deletions
diff --git a/arch/powerpc/kvm/book3s_segment.S b/arch/powerpc/kvm/book3s_segment.S
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index 000000000..1f492aa4c
--- /dev/null
+++ b/arch/powerpc/kvm/book3s_segment.S
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+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ *
+ * Copyright SUSE Linux Products GmbH 2010
+ *
+ * Authors: Alexander Graf <agraf@suse.de>
+ */
+
+/* Real mode helpers */
+
+#include <asm/asm-compat.h>
+#include <asm/feature-fixups.h>
+
+#if defined(CONFIG_PPC_BOOK3S_64)
+
+#define GET_SHADOW_VCPU(reg) \
+ mr reg, r13
+
+#elif defined(CONFIG_PPC_BOOK3S_32)
+
+#define GET_SHADOW_VCPU(reg) \
+ tophys(reg, r2); \
+ lwz reg, (THREAD + THREAD_KVM_SVCPU)(reg); \
+ tophys(reg, reg)
+
+#endif
+
+/* Disable for nested KVM */
+#define USE_QUICK_LAST_INST
+
+
+/* Get helper functions for subarch specific functionality */
+
+#if defined(CONFIG_PPC_BOOK3S_64)
+#include "book3s_64_slb.S"
+#elif defined(CONFIG_PPC_BOOK3S_32)
+#include "book3s_32_sr.S"
+#endif
+
+/******************************************************************************
+ * *
+ * Entry code *
+ * *
+ *****************************************************************************/
+
+.global kvmppc_handler_trampoline_enter
+kvmppc_handler_trampoline_enter:
+
+ /* Required state:
+ *
+ * MSR = ~IR|DR
+ * R1 = host R1
+ * R2 = host R2
+ * R4 = guest shadow MSR
+ * R5 = normal host MSR
+ * R6 = current host MSR (EE, IR, DR off)
+ * LR = highmem guest exit code
+ * all other volatile GPRS = free
+ * SVCPU[CR] = guest CR
+ * SVCPU[XER] = guest XER
+ * SVCPU[CTR] = guest CTR
+ * SVCPU[LR] = guest LR
+ */
+
+ /* r3 = shadow vcpu */
+ GET_SHADOW_VCPU(r3)
+
+ /* Save guest exit handler address and MSR */
+ mflr r0
+ PPC_STL r0, HSTATE_VMHANDLER(r3)
+ PPC_STL r5, HSTATE_HOST_MSR(r3)
+
+ /* Save R1/R2 in the PACA (64-bit) or shadow_vcpu (32-bit) */
+ PPC_STL r1, HSTATE_HOST_R1(r3)
+ PPC_STL r2, HSTATE_HOST_R2(r3)
+
+ /* Activate guest mode, so faults get handled by KVM */
+ li r11, KVM_GUEST_MODE_GUEST
+ stb r11, HSTATE_IN_GUEST(r3)
+
+ /* Switch to guest segment. This is subarch specific. */
+ LOAD_GUEST_SEGMENTS
+
+#ifdef CONFIG_PPC_BOOK3S_64
+BEGIN_FTR_SECTION
+ /* Save host FSCR */
+ mfspr r8, SPRN_FSCR
+ std r8, HSTATE_HOST_FSCR(r13)
+ /* Set FSCR during guest execution */
+ ld r9, SVCPU_SHADOW_FSCR(r13)
+ mtspr SPRN_FSCR, r9
+END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S)
+
+ /* Some guests may need to have dcbz set to 32 byte length.
+ *
+ * Usually we ensure that by patching the guest's instructions
+ * to trap on dcbz and emulate it in the hypervisor.
+ *
+ * If we can, we should tell the CPU to use 32 byte dcbz though,
+ * because that's a lot faster.
+ */
+ lbz r0, HSTATE_RESTORE_HID5(r3)
+ cmpwi r0, 0
+ beq no_dcbz32_on
+
+ mfspr r0,SPRN_HID5
+ ori r0, r0, 0x80 /* XXX HID5_dcbz32 = 0x80 */
+ mtspr SPRN_HID5,r0
+no_dcbz32_on:
+
+#endif /* CONFIG_PPC_BOOK3S_64 */
+
+ /* Enter guest */
+
+ PPC_LL r8, SVCPU_CTR(r3)
+ PPC_LL r9, SVCPU_LR(r3)
+ lwz r10, SVCPU_CR(r3)
+ PPC_LL r11, SVCPU_XER(r3)
+
+ mtctr r8
+ mtlr r9
+ mtcr r10
+ mtxer r11
+
+ /* Move SRR0 and SRR1 into the respective regs */
+ PPC_LL r9, SVCPU_PC(r3)
+ /* First clear RI in our current MSR value */
+ li r0, MSR_RI
+ andc r6, r6, r0
+
+ PPC_LL r0, SVCPU_R0(r3)
+ PPC_LL r1, SVCPU_R1(r3)
+ PPC_LL r2, SVCPU_R2(r3)
+ PPC_LL r5, SVCPU_R5(r3)
+ PPC_LL r7, SVCPU_R7(r3)
+ PPC_LL r8, SVCPU_R8(r3)
+ PPC_LL r10, SVCPU_R10(r3)
+ PPC_LL r11, SVCPU_R11(r3)
+ PPC_LL r12, SVCPU_R12(r3)
+ PPC_LL r13, SVCPU_R13(r3)
+
+ MTMSR_EERI(r6)
+ mtsrr0 r9
+ mtsrr1 r4
+
+ PPC_LL r4, SVCPU_R4(r3)
+ PPC_LL r6, SVCPU_R6(r3)
+ PPC_LL r9, SVCPU_R9(r3)
+ PPC_LL r3, (SVCPU_R3)(r3)
+
+ RFI_TO_GUEST
+kvmppc_handler_trampoline_enter_end:
+
+
+
+/******************************************************************************
+ * *
+ * Exit code *
+ * *
+ *****************************************************************************/
+
+.global kvmppc_interrupt_pr
+kvmppc_interrupt_pr:
+ /* 64-bit entry. Register usage at this point:
+ *
+ * SPRG_SCRATCH0 = guest R13
+ * R12 = (guest CR << 32) | exit handler id
+ * R13 = PACA
+ * HSTATE.SCRATCH0 = guest R12
+ */
+#ifdef CONFIG_PPC64
+ /* Match 32-bit entry */
+ rotldi r12, r12, 32 /* Flip R12 halves for stw */
+ stw r12, HSTATE_SCRATCH1(r13) /* CR is now in the low half */
+ srdi r12, r12, 32 /* shift trap into low half */
+#endif
+
+.global kvmppc_handler_trampoline_exit
+kvmppc_handler_trampoline_exit:
+ /* Register usage at this point:
+ *
+ * SPRG_SCRATCH0 = guest R13
+ * R12 = exit handler id
+ * R13 = shadow vcpu (32-bit) or PACA (64-bit)
+ * HSTATE.SCRATCH0 = guest R12
+ * HSTATE.SCRATCH1 = guest CR
+ */
+
+ /* Save registers */
+
+ PPC_STL r0, SVCPU_R0(r13)
+ PPC_STL r1, SVCPU_R1(r13)
+ PPC_STL r2, SVCPU_R2(r13)
+ PPC_STL r3, SVCPU_R3(r13)
+ PPC_STL r4, SVCPU_R4(r13)
+ PPC_STL r5, SVCPU_R5(r13)
+ PPC_STL r6, SVCPU_R6(r13)
+ PPC_STL r7, SVCPU_R7(r13)
+ PPC_STL r8, SVCPU_R8(r13)
+ PPC_STL r9, SVCPU_R9(r13)
+ PPC_STL r10, SVCPU_R10(r13)
+ PPC_STL r11, SVCPU_R11(r13)
+
+ /* Restore R1/R2 so we can handle faults */
+ PPC_LL r1, HSTATE_HOST_R1(r13)
+ PPC_LL r2, HSTATE_HOST_R2(r13)
+
+ /* Save guest PC and MSR */
+#ifdef CONFIG_PPC64
+BEGIN_FTR_SECTION
+ andi. r0, r12, 0x2
+ cmpwi cr1, r0, 0
+ beq 1f
+ mfspr r3,SPRN_HSRR0
+ mfspr r4,SPRN_HSRR1
+ andi. r12,r12,0x3ffd
+ b 2f
+END_FTR_SECTION_IFSET(CPU_FTR_HVMODE)
+#endif
+1: mfsrr0 r3
+ mfsrr1 r4
+2:
+ PPC_STL r3, SVCPU_PC(r13)
+ PPC_STL r4, SVCPU_SHADOW_SRR1(r13)
+
+ /* Get scratch'ed off registers */
+ GET_SCRATCH0(r9)
+ PPC_LL r8, HSTATE_SCRATCH0(r13)
+ lwz r7, HSTATE_SCRATCH1(r13)
+
+ PPC_STL r9, SVCPU_R13(r13)
+ PPC_STL r8, SVCPU_R12(r13)
+ stw r7, SVCPU_CR(r13)
+
+ /* Save more register state */
+
+ mfxer r5
+ mfdar r6
+ mfdsisr r7
+ mfctr r8
+ mflr r9
+
+ PPC_STL r5, SVCPU_XER(r13)
+ PPC_STL r6, SVCPU_FAULT_DAR(r13)
+ stw r7, SVCPU_FAULT_DSISR(r13)
+ PPC_STL r8, SVCPU_CTR(r13)
+ PPC_STL r9, SVCPU_LR(r13)
+
+ /*
+ * In order for us to easily get the last instruction,
+ * we got the #vmexit at, we exploit the fact that the
+ * virtual layout is still the same here, so we can just
+ * ld from the guest's PC address
+ */
+
+ /* We only load the last instruction when it's safe */
+ cmpwi r12, BOOK3S_INTERRUPT_DATA_STORAGE
+ beq ld_last_inst
+ cmpwi r12, BOOK3S_INTERRUPT_PROGRAM
+ beq ld_last_inst
+ cmpwi r12, BOOK3S_INTERRUPT_SYSCALL
+ beq ld_last_prev_inst
+ cmpwi r12, BOOK3S_INTERRUPT_ALIGNMENT
+ beq- ld_last_inst
+#ifdef CONFIG_PPC64
+BEGIN_FTR_SECTION
+ cmpwi r12, BOOK3S_INTERRUPT_H_EMUL_ASSIST
+ beq- ld_last_inst
+END_FTR_SECTION_IFSET(CPU_FTR_HVMODE)
+BEGIN_FTR_SECTION
+ cmpwi r12, BOOK3S_INTERRUPT_FAC_UNAVAIL
+ beq- ld_last_inst
+END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S)
+#endif
+
+ b no_ld_last_inst
+
+ld_last_prev_inst:
+ addi r3, r3, -4
+
+ld_last_inst:
+ /* Save off the guest instruction we're at */
+
+ /* In case lwz faults */
+ li r0, KVM_INST_FETCH_FAILED
+
+#ifdef USE_QUICK_LAST_INST
+
+ /* Set guest mode to 'jump over instruction' so if lwz faults
+ * we'll just continue at the next IP. */
+ li r9, KVM_GUEST_MODE_SKIP
+ stb r9, HSTATE_IN_GUEST(r13)
+
+ /* 1) enable paging for data */
+ mfmsr r9
+ ori r11, r9, MSR_DR /* Enable paging for data */
+ mtmsr r11
+ sync
+ /* 2) fetch the instruction */
+ lwz r0, 0(r3)
+ /* 3) disable paging again */
+ mtmsr r9
+ sync
+
+#endif
+ stw r0, SVCPU_LAST_INST(r13)
+
+no_ld_last_inst:
+
+ /* Unset guest mode */
+ li r9, KVM_GUEST_MODE_NONE
+ stb r9, HSTATE_IN_GUEST(r13)
+
+ /* Switch back to host MMU */
+ LOAD_HOST_SEGMENTS
+
+#ifdef CONFIG_PPC_BOOK3S_64
+
+ lbz r5, HSTATE_RESTORE_HID5(r13)
+ cmpwi r5, 0
+ beq no_dcbz32_off
+
+ li r4, 0
+ mfspr r5,SPRN_HID5
+ rldimi r5,r4,6,56
+ mtspr SPRN_HID5,r5
+
+no_dcbz32_off:
+
+BEGIN_FTR_SECTION
+ /* Save guest FSCR on a FAC_UNAVAIL interrupt */
+ cmpwi r12, BOOK3S_INTERRUPT_FAC_UNAVAIL
+ bne+ no_fscr_save
+ mfspr r7, SPRN_FSCR
+ std r7, SVCPU_SHADOW_FSCR(r13)
+no_fscr_save:
+ /* Restore host FSCR */
+ ld r8, HSTATE_HOST_FSCR(r13)
+ mtspr SPRN_FSCR, r8
+END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S)
+
+#endif /* CONFIG_PPC_BOOK3S_64 */
+
+ /*
+ * For some interrupts, we need to call the real Linux
+ * handler, so it can do work for us. This has to happen
+ * as if the interrupt arrived from the kernel though,
+ * so let's fake it here where most state is restored.
+ *
+ * Having set up SRR0/1 with the address where we want
+ * to continue with relocation on (potentially in module
+ * space), we either just go straight there with rfi[d],
+ * or we jump to an interrupt handler if there is an
+ * interrupt to be handled first. In the latter case,
+ * the rfi[d] at the end of the interrupt handler will
+ * get us back to where we want to continue.
+ */
+
+ /* Register usage at this point:
+ *
+ * R1 = host R1
+ * R2 = host R2
+ * R10 = raw exit handler id
+ * R12 = exit handler id
+ * R13 = shadow vcpu (32-bit) or PACA (64-bit)
+ * SVCPU.* = guest *
+ *
+ */
+
+ PPC_LL r6, HSTATE_HOST_MSR(r13)
+#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
+ /*
+ * We don't want to change MSR[TS] bits via rfi here.
+ * The actual TM handling logic will be in host with
+ * recovered DR/IR bits after HSTATE_VMHANDLER.
+ * And MSR_TM can be enabled in HOST_MSR so rfid may
+ * not suppress this change and can lead to exception.
+ * Manually set MSR to prevent TS state change here.
+ */
+ mfmsr r7
+ rldicl r7, r7, 64 - MSR_TS_S_LG, 62
+ rldimi r6, r7, MSR_TS_S_LG, 63 - MSR_TS_T_LG
+#endif
+ PPC_LL r8, HSTATE_VMHANDLER(r13)
+
+#ifdef CONFIG_PPC64
+BEGIN_FTR_SECTION
+ beq cr1, 1f
+ mtspr SPRN_HSRR1, r6
+ mtspr SPRN_HSRR0, r8
+END_FTR_SECTION_IFSET(CPU_FTR_HVMODE)
+#endif
+1: /* Restore host msr -> SRR1 */
+ mtsrr1 r6
+ /* Load highmem handler address */
+ mtsrr0 r8
+
+ /* RFI into the highmem handler, or jump to interrupt handler */
+ cmpwi r12, BOOK3S_INTERRUPT_EXTERNAL
+ beqa BOOK3S_INTERRUPT_EXTERNAL
+ cmpwi r12, BOOK3S_INTERRUPT_DECREMENTER
+ beqa BOOK3S_INTERRUPT_DECREMENTER
+ cmpwi r12, BOOK3S_INTERRUPT_PERFMON
+ beqa BOOK3S_INTERRUPT_PERFMON
+ cmpwi r12, BOOK3S_INTERRUPT_DOORBELL
+ beqa BOOK3S_INTERRUPT_DOORBELL
+
+ RFI_TO_KERNEL
+kvmppc_handler_trampoline_exit_end:
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