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| -rw-r--r-- | arch/powerpc/kvm/book3s_segment.S | 257 |
1 files changed, 257 insertions, 0 deletions
diff --git a/arch/powerpc/kvm/book3s_segment.S b/arch/powerpc/kvm/book3s_segment.S new file mode 100644 index 000000000000..4c0d1d85d20a --- /dev/null +++ b/arch/powerpc/kvm/book3s_segment.S @@ -0,0 +1,257 @@ +/* + * 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 */ + +#if defined(CONFIG_PPC_BOOK3S_64) + +#define GET_SHADOW_VCPU(reg) \ + addi reg, r13, PACA_KVM_SVCPU + +#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 + * R13 = PACA + * R1 = host R1 + * R2 = host R2 + * R10 = guest MSR + * 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) + + /* Move SRR0 and SRR1 into the respective regs */ + PPC_LL r9, SVCPU_PC(r3) + mtsrr0 r9 + mtsrr1 r10 + + /* Activate guest mode, so faults get handled by KVM */ + li r11, KVM_GUEST_MODE_GUEST + stb r11, SVCPU_IN_GUEST(r3) + + /* Switch to guest segment. This is subarch specific. */ + LOAD_GUEST_SEGMENTS + + /* Enter guest */ + + PPC_LL r4, (SVCPU_CTR)(r3) + PPC_LL r5, (SVCPU_LR)(r3) + lwz r6, (SVCPU_CR)(r3) + lwz r7, (SVCPU_XER)(r3) + + mtctr r4 + mtlr r5 + mtcr r6 + mtxer r7 + + PPC_LL r0, (SVCPU_R0)(r3) + PPC_LL r1, (SVCPU_R1)(r3) + PPC_LL r2, (SVCPU_R2)(r3) + PPC_LL r4, (SVCPU_R4)(r3) + PPC_LL r5, (SVCPU_R5)(r3) + PPC_LL r6, (SVCPU_R6)(r3) + PPC_LL r7, (SVCPU_R7)(r3) + PPC_LL r8, (SVCPU_R8)(r3) + PPC_LL r9, (SVCPU_R9)(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) + + PPC_LL r3, (SVCPU_R3)(r3) + + RFI +kvmppc_handler_trampoline_enter_end: + + + +/****************************************************************************** + * * + * Exit code * + * * + *****************************************************************************/ + +.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 - SHADOW_VCPU_OFF [=PACA on PPC64] + * SVCPU.SCRATCH0 = guest R12 + * SVCPU.SCRATCH1 = guest CR + * + */ + + /* Save registers */ + + PPC_STL r0, (SHADOW_VCPU_OFF + SVCPU_R0)(r13) + PPC_STL r1, (SHADOW_VCPU_OFF + SVCPU_R1)(r13) + PPC_STL r2, (SHADOW_VCPU_OFF + SVCPU_R2)(r13) + PPC_STL r3, (SHADOW_VCPU_OFF + SVCPU_R3)(r13) + PPC_STL r4, (SHADOW_VCPU_OFF + SVCPU_R4)(r13) + PPC_STL r5, (SHADOW_VCPU_OFF + SVCPU_R5)(r13) + PPC_STL r6, (SHADOW_VCPU_OFF + SVCPU_R6)(r13) + PPC_STL r7, (SHADOW_VCPU_OFF + SVCPU_R7)(r13) + PPC_STL r8, (SHADOW_VCPU_OFF + SVCPU_R8)(r13) + PPC_STL r9, (SHADOW_VCPU_OFF + SVCPU_R9)(r13) + PPC_STL r10, (SHADOW_VCPU_OFF + SVCPU_R10)(r13) + PPC_STL r11, (SHADOW_VCPU_OFF + SVCPU_R11)(r13) + + /* Restore R1/R2 so we can handle faults */ + PPC_LL r1, (SHADOW_VCPU_OFF + SVCPU_HOST_R1)(r13) + PPC_LL r2, (SHADOW_VCPU_OFF + SVCPU_HOST_R2)(r13) + + /* Save guest PC and MSR */ + mfsrr0 r3 + mfsrr1 r4 + + PPC_STL r3, (SHADOW_VCPU_OFF + SVCPU_PC)(r13) + PPC_STL r4, (SHADOW_VCPU_OFF + SVCPU_SHADOW_SRR1)(r13) + + /* Get scratch'ed off registers */ + mfspr r9, SPRN_SPRG_SCRATCH0 + PPC_LL r8, (SHADOW_VCPU_OFF + SVCPU_SCRATCH0)(r13) + lwz r7, (SHADOW_VCPU_OFF + SVCPU_SCRATCH1)(r13) + + PPC_STL r9, (SHADOW_VCPU_OFF + SVCPU_R13)(r13) + PPC_STL r8, (SHADOW_VCPU_OFF + SVCPU_R12)(r13) + stw r7, (SHADOW_VCPU_OFF + SVCPU_CR)(r13) + + /* Save more register state */ + + mfxer r5 + mfdar r6 + mfdsisr r7 + mfctr r8 + mflr r9 + + stw r5, (SHADOW_VCPU_OFF + SVCPU_XER)(r13) + PPC_STL r6, (SHADOW_VCPU_OFF + SVCPU_FAULT_DAR)(r13) + stw r7, (SHADOW_VCPU_OFF + SVCPU_FAULT_DSISR)(r13) + PPC_STL r8, (SHADOW_VCPU_OFF + SVCPU_CTR)(r13) + PPC_STL r9, (SHADOW_VCPU_OFF + 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 + + b no_ld_last_inst + +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, (SHADOW_VCPU_OFF + SVCPU_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, (SHADOW_VCPU_OFF + SVCPU_LAST_INST)(r13) + +no_ld_last_inst: + + /* Unset guest mode */ + li r9, KVM_GUEST_MODE_NONE + stb r9, (SHADOW_VCPU_OFF + SVCPU_IN_GUEST)(r13) + + /* Switch back to host MMU */ + LOAD_HOST_SEGMENTS + + /* Register usage at this point: + * + * R1 = host R1 + * R2 = host R2 + * R12 = exit handler id + * R13 = shadow vcpu - SHADOW_VCPU_OFF [=PACA on PPC64] + * SVCPU.* = guest * + * + */ + + /* RFI into the highmem handler */ + mfmsr r7 + ori r7, r7, MSR_IR|MSR_DR|MSR_RI|MSR_ME /* Enable paging */ + mtsrr1 r7 + /* Load highmem handler address */ + PPC_LL r8, (SHADOW_VCPU_OFF + SVCPU_VMHANDLER)(r13) + mtsrr0 r8 + + RFI +kvmppc_handler_trampoline_exit_end: |
