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-rw-r--r--arch/powerpc/kvm/book3s_interrupts.S320
1 files changed, 320 insertions, 0 deletions
diff --git a/arch/powerpc/kvm/book3s_interrupts.S b/arch/powerpc/kvm/book3s_interrupts.S
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+++ b/arch/powerpc/kvm/book3s_interrupts.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 2009
+ *
+ * Authors: Alexander Graf <agraf@suse.de>
+ */
+
+#include <asm/ppc_asm.h>
+#include <asm/kvm_asm.h>
+#include <asm/reg.h>
+#include <asm/page.h>
+#include <asm/asm-offsets.h>
+#include <asm/exception-64s.h>
+
+#if defined(CONFIG_PPC_BOOK3S_64)
+
+#define ULONG_SIZE 8
+#define FUNC(name) GLUE(.,name)
+
+#define GET_SHADOW_VCPU(reg) \
+ addi reg, r13, PACA_KVM_SVCPU
+
+#define DISABLE_INTERRUPTS \
+ mfmsr r0; \
+ rldicl r0,r0,48,1; \
+ rotldi r0,r0,16; \
+ mtmsrd r0,1; \
+
+#elif defined(CONFIG_PPC_BOOK3S_32)
+
+#define ULONG_SIZE 4
+#define FUNC(name) name
+
+#define GET_SHADOW_VCPU(reg) \
+ lwz reg, (THREAD + THREAD_KVM_SVCPU)(r2)
+
+#define DISABLE_INTERRUPTS \
+ mfmsr r0; \
+ rlwinm r0,r0,0,17,15; \
+ mtmsr r0; \
+
+#endif /* CONFIG_PPC_BOOK3S_XX */
+
+
+#define VCPU_GPR(n) (VCPU_GPRS + (n * ULONG_SIZE))
+#define VCPU_LOAD_NVGPRS(vcpu) \
+ PPC_LL r14, VCPU_GPR(r14)(vcpu); \
+ PPC_LL r15, VCPU_GPR(r15)(vcpu); \
+ PPC_LL r16, VCPU_GPR(r16)(vcpu); \
+ PPC_LL r17, VCPU_GPR(r17)(vcpu); \
+ PPC_LL r18, VCPU_GPR(r18)(vcpu); \
+ PPC_LL r19, VCPU_GPR(r19)(vcpu); \
+ PPC_LL r20, VCPU_GPR(r20)(vcpu); \
+ PPC_LL r21, VCPU_GPR(r21)(vcpu); \
+ PPC_LL r22, VCPU_GPR(r22)(vcpu); \
+ PPC_LL r23, VCPU_GPR(r23)(vcpu); \
+ PPC_LL r24, VCPU_GPR(r24)(vcpu); \
+ PPC_LL r25, VCPU_GPR(r25)(vcpu); \
+ PPC_LL r26, VCPU_GPR(r26)(vcpu); \
+ PPC_LL r27, VCPU_GPR(r27)(vcpu); \
+ PPC_LL r28, VCPU_GPR(r28)(vcpu); \
+ PPC_LL r29, VCPU_GPR(r29)(vcpu); \
+ PPC_LL r30, VCPU_GPR(r30)(vcpu); \
+ PPC_LL r31, VCPU_GPR(r31)(vcpu); \
+
+/*****************************************************************************
+ * *
+ * Guest entry / exit code that is in kernel module memory (highmem) *
+ * *
+ ****************************************************************************/
+
+/* Registers:
+ * r3: kvm_run pointer
+ * r4: vcpu pointer
+ */
+_GLOBAL(__kvmppc_vcpu_entry)
+
+kvm_start_entry:
+ /* Write correct stack frame */
+ mflr r0
+ PPC_STL r0,PPC_LR_STKOFF(r1)
+
+ /* Save host state to the stack */
+ PPC_STLU r1, -SWITCH_FRAME_SIZE(r1)
+
+ /* Save r3 (kvm_run) and r4 (vcpu) */
+ SAVE_2GPRS(3, r1)
+
+ /* Save non-volatile registers (r14 - r31) */
+ SAVE_NVGPRS(r1)
+
+ /* Save LR */
+ PPC_STL r0, _LINK(r1)
+
+ /* Load non-volatile guest state from the vcpu */
+ VCPU_LOAD_NVGPRS(r4)
+
+ GET_SHADOW_VCPU(r5)
+
+ /* Save R1/R2 in the PACA */
+ PPC_STL r1, SVCPU_HOST_R1(r5)
+ PPC_STL r2, SVCPU_HOST_R2(r5)
+
+ /* XXX swap in/out on load? */
+ PPC_LL r3, VCPU_HIGHMEM_HANDLER(r4)
+ PPC_STL r3, SVCPU_VMHANDLER(r5)
+
+kvm_start_lightweight:
+
+ PPC_LL r10, VCPU_SHADOW_MSR(r4) /* r10 = vcpu->arch.shadow_msr */
+
+ DISABLE_INTERRUPTS
+
+#ifdef CONFIG_PPC_BOOK3S_64
+ /* 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.
+ */
+
+ PPC_LL r3, VCPU_HFLAGS(r4)
+ rldicl. r3, r3, 0, 63 /* CR = ((r3 & 1) == 0) */
+ beq no_dcbz32_on
+
+ mfspr r3,SPRN_HID5
+ ori r3, r3, 0x80 /* XXX HID5_dcbz32 = 0x80 */
+ mtspr SPRN_HID5,r3
+
+no_dcbz32_on:
+
+#endif /* CONFIG_PPC_BOOK3S_64 */
+
+ PPC_LL r6, VCPU_RMCALL(r4)
+ mtctr r6
+
+ PPC_LL r3, VCPU_TRAMPOLINE_ENTER(r4)
+ LOAD_REG_IMMEDIATE(r4, MSR_KERNEL & ~(MSR_IR | MSR_DR))
+
+ /* Jump to segment patching handler and into our guest */
+ bctr
+
+/*
+ * This is the handler in module memory. It gets jumped at from the
+ * lowmem trampoline code, so it's basically the guest exit code.
+ *
+ */
+
+.global kvmppc_handler_highmem
+kvmppc_handler_highmem:
+
+ /*
+ * Register usage at this point:
+ *
+ * R1 = host R1
+ * R2 = host R2
+ * R12 = exit handler id
+ * R13 = PACA
+ * SVCPU.* = guest *
+ *
+ */
+
+ /* R7 = vcpu */
+ PPC_LL r7, GPR4(r1)
+
+#ifdef CONFIG_PPC_BOOK3S_64
+
+ PPC_LL r5, VCPU_HFLAGS(r7)
+ rldicl. r5, r5, 0, 63 /* CR = ((r5 & 1) == 0) */
+ beq no_dcbz32_off
+
+ li r4, 0
+ mfspr r5,SPRN_HID5
+ rldimi r5,r4,6,56
+ mtspr SPRN_HID5,r5
+
+no_dcbz32_off:
+
+#endif /* CONFIG_PPC_BOOK3S_64 */
+
+ PPC_STL r14, VCPU_GPR(r14)(r7)
+ PPC_STL r15, VCPU_GPR(r15)(r7)
+ PPC_STL r16, VCPU_GPR(r16)(r7)
+ PPC_STL r17, VCPU_GPR(r17)(r7)
+ PPC_STL r18, VCPU_GPR(r18)(r7)
+ PPC_STL r19, VCPU_GPR(r19)(r7)
+ PPC_STL r20, VCPU_GPR(r20)(r7)
+ PPC_STL r21, VCPU_GPR(r21)(r7)
+ PPC_STL r22, VCPU_GPR(r22)(r7)
+ PPC_STL r23, VCPU_GPR(r23)(r7)
+ PPC_STL r24, VCPU_GPR(r24)(r7)
+ PPC_STL r25, VCPU_GPR(r25)(r7)
+ PPC_STL r26, VCPU_GPR(r26)(r7)
+ PPC_STL r27, VCPU_GPR(r27)(r7)
+ PPC_STL r28, VCPU_GPR(r28)(r7)
+ PPC_STL r29, VCPU_GPR(r29)(r7)
+ PPC_STL r30, VCPU_GPR(r30)(r7)
+ PPC_STL r31, VCPU_GPR(r31)(r7)
+
+ /* Restore host msr -> SRR1 */
+ PPC_LL r6, VCPU_HOST_MSR(r7)
+
+ /*
+ * 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.
+ *
+ * Call Linux for hardware interrupts/decrementer
+ * r3 = address of interrupt handler (exit reason)
+ */
+
+ cmpwi r12, BOOK3S_INTERRUPT_EXTERNAL
+ beq call_linux_handler
+ cmpwi r12, BOOK3S_INTERRUPT_DECREMENTER
+ beq call_linux_handler
+ cmpwi r12, BOOK3S_INTERRUPT_PERFMON
+ beq call_linux_handler
+
+ /* Back to EE=1 */
+ mtmsr r6
+ sync
+ b kvm_return_point
+
+call_linux_handler:
+
+ /*
+ * If we land here we need to jump back to the handler we
+ * came from.
+ *
+ * We have a page that we can access from real mode, so let's
+ * jump back to that and use it as a trampoline to get back into the
+ * interrupt handler!
+ *
+ * R3 still contains the exit code,
+ * R5 VCPU_HOST_RETIP and
+ * R6 VCPU_HOST_MSR
+ */
+
+ /* Restore host IP -> SRR0 */
+ PPC_LL r5, VCPU_HOST_RETIP(r7)
+
+ /* XXX Better move to a safe function?
+ * What if we get an HTAB flush in between mtsrr0 and mtsrr1? */
+
+ mtlr r12
+
+ PPC_LL r4, VCPU_TRAMPOLINE_LOWMEM(r7)
+ mtsrr0 r4
+ LOAD_REG_IMMEDIATE(r3, MSR_KERNEL & ~(MSR_IR | MSR_DR))
+ mtsrr1 r3
+
+ RFI
+
+.global kvm_return_point
+kvm_return_point:
+
+ /* Jump back to lightweight entry if we're supposed to */
+ /* go back into the guest */
+
+ /* Pass the exit number as 3rd argument to kvmppc_handle_exit */
+ mr r5, r12
+
+ /* Restore r3 (kvm_run) and r4 (vcpu) */
+ REST_2GPRS(3, r1)
+ bl FUNC(kvmppc_handle_exit)
+
+ /* If RESUME_GUEST, get back in the loop */
+ cmpwi r3, RESUME_GUEST
+ beq kvm_loop_lightweight
+
+ cmpwi r3, RESUME_GUEST_NV
+ beq kvm_loop_heavyweight
+
+kvm_exit_loop:
+
+ PPC_LL r4, _LINK(r1)
+ mtlr r4
+
+ /* Restore non-volatile host registers (r14 - r31) */
+ REST_NVGPRS(r1)
+
+ addi r1, r1, SWITCH_FRAME_SIZE
+ blr
+
+kvm_loop_heavyweight:
+
+ PPC_LL r4, _LINK(r1)
+ PPC_STL r4, (PPC_LR_STKOFF + SWITCH_FRAME_SIZE)(r1)
+
+ /* Load vcpu and cpu_run */
+ REST_2GPRS(3, r1)
+
+ /* Load non-volatile guest state from the vcpu */
+ VCPU_LOAD_NVGPRS(r4)
+
+ /* Jump back into the beginning of this function */
+ b kvm_start_lightweight
+
+kvm_loop_lightweight:
+
+ /* We'll need the vcpu pointer */
+ REST_GPR(4, r1)
+
+ /* Jump back into the beginning of this function */
+ b kvm_start_lightweight