diff options
Diffstat (limited to 'arch/powerpc/kvm/book3s_segment.S')
| -rw-r--r-- | arch/powerpc/kvm/book3s_segment.S | 427 |
1 files changed, 427 insertions, 0 deletions
diff --git a/arch/powerpc/kvm/book3s_segment.S b/arch/powerpc/kvm/book3s_segment.S new file mode 100644 index 000000000..e5c542a7c --- /dev/null +++ b/arch/powerpc/kvm/book3s_segment.S @@ -0,0 +1,427 @@ +/* + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License, version 2, as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. + * + * 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 + * HSTATE.SCRATCH1 = guest CTR if RELOCATABLE + */ +#ifdef CONFIG_PPC64 + /* Match 32-bit entry */ +#ifdef CONFIG_RELOCATABLE + std r9, HSTATE_SCRATCH2(r13) + ld r9, HSTATE_SCRATCH1(r13) + mtctr r9 + ld r9, HSTATE_SCRATCH2(r13) +#endif + 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: |