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-rw-r--r--arch/powerpc/kvm/book3s_segment.S259
1 files changed, 259 insertions, 0 deletions
diff --git a/arch/powerpc/kvm/book3s_segment.S b/arch/powerpc/kvm/book3s_segment.S
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index 00000000000..7c52ed0b705
--- /dev/null
+++ b/arch/powerpc/kvm/book3s_segment.S
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+/*
+ * 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
+ cmpwi r12, BOOK3S_INTERRUPT_ALIGNMENT
+ 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:
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