kvm代码架构简单分析
kvm代码结构简析
(2011-03-30 16:57:28)
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标签： 杂谈 |
以booke500为例：
初始化;
kvmppc_e500_init===============================arch/powerpc/kvm/e500.c
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kvm_init kvmppc_booke_init
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kvm_arch_init, kvm_arch_hardware_setup, register(kvm_dev)
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kvm_sched_in ---------------- kvm_arch_vcpu_load
kvm_sched_out ---------------- kvm_arch_vcpu_put
其中register kvm_dev中提供了一ioctl操作函数：
kvm_dev_ioctl
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| kvm_arch_dev_ioctl 其他对/dev/kvm的操作
kvm_dev_ioctl_create_vm生成vm文件句柄，可以通过此句柄对vm进行操作
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kvm_create_vm , anon_inode_getfd("kvm-vm",&kvm_vm_fops, kvm, O_RDWR)
其中anon_inode_getfd创建file fd ，其创建的所有file共享一个inode。对vm的操作
实际上就是对此file的操作，因此对其ioctl调用的是kvm_vm_fops中的成员函数：
kvm_vm_ioctl
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KVM_CREATE_VCPU: kvm_vm_ioctl_create_vcpu
KVM_SET_USER_MEMORY_REGION: kvm_vm_ioctl_set_memory_region
KVM_GET_DIRTY_LOG: kvm_vm_ioctl_get_dirty_log
KVM_REGISTER_COALESCED_MMIO: kvm_vm_ioctl_register_coalesced_mmio
KVM_UNREGISTER_COALESCED_MMIO: kvm_vm_ioctl_unregister_coalesced_mmio
KVM_IRQFD: kvm_irqfd
KVM_IOEVENTFD: kvm_ioeventfd
KVM_SET_BOOT_CPU_ID:
default : kvm_arch_vm_ioctl,
kvm_vm_ioctl_assigned_device
以下对其调用的函数关系做分析：
1.
kvm_vm_ioctl_create_vcpu
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kvm_arch_vcpu_create--kvmppc_core_vcpu_create--kvm_vcpu_init--kvm_arch_vcpu_init
kvmppc_e500_tlb_init
kvm_arch_vcpu_setup--kvmppc_core_vcpu_setup--kvmppc_e500_tlb_setup
create_vcpu_fd ---anon_inode_getfd("kvm-vcpu",&kvm_vcpu_fops, vcpu, O_RDWR)
其中create_vcpu_fd生成对vcpu操作的文件fd，其ioctl调用的是kvm_vcpu_fops中的
kvm_vcpu_ioctl
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KVM_RUN: kvm_arch_vcpu_ioctl_run
KVM_GET_REGS: kvm_arch_vcpu_ioctl_get_regs
KVM_SET_REGS: kvm_arch_vcpu_ioctl_set_regs
KVM_GET_SREGS: kvm_arch_vcpu_ioctl_get_sregs
KVM_SET_SREGS: kvm_arch_vcpu_ioctl_set_sregs
KVM_GET_MP_STATE: kvm_arch_vcpu_ioctl_get_mpstate
KVM_SET_MP_STATE: kvm_arch_vcpu_ioctl_set_mpstate
KVM_TRANSLATE: kvm_arch_vcpu_ioctl_translate
KVM_SET_GUEST_DEBUG: kvm_arch_vcpu_ioctl_set_guest_debug
KVM_SET_SIGNAL_MASK: kvm_vcpu_ioctl_set_sigmask
KVM_GET_FPU: kvm_arch_vcpu_ioctl_get_fpu
KVM_SET_FPU: kvm_arch_vcpu_ioctl_set_fpu
(ppc s390结构下）
KVM_S390_INTERRUPT:
KVM_INTERRUPT
default: kvm_arch_vcpu_ioctl
其中：
kvm_arch_vcpu_ioctl_run -----__kvmppc_vcpu_run
kvm_arch_vcpu_ioctl
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KVM_INTERRUPT: kvm_vcpu_ioctl_interrupt
KVM_ENABLE_CAP: kvm_vcpu_ioctl_enable_cap
2.
kvm_irqfd
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kvm_irqfd_assign
3
kvm_ioeventfd
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kvm_assign_ioeventfd
======================================
二、中断处理过程
以e500为例，powerpc专门分配了页用来存储中断处理入口地址
入口地址为变量kvmppc_booke_handlers
在arch/powerpc/kvm/booke_interrupt.S中定义了一些列中断处理代码：
72 _GLOBAL(kvmppc_handlers_start)
73 KVM_HANDLERBOOKE_INTERRUPT_CRITICAL
74 KVM_HANDLERBOOKE_INTERRUPT_MACHINE_CHECK
75 KVM_HANDLERBOOKE_INTERRUPT_DATA_STORAGE
76 KVM_HANDLERBOOKE_INTERRUPT_INST_STORAGE
77 KVM_HANDLERBOOKE_INTERRUPT_EXTERNAL
78 KVM_HANDLERBOOKE_INTERRUPT_ALIGNMENT
79 KVM_HANDLER BOOKE_INTERRUPT_PROGRAM
80 KVM_HANDLERBOOKE_INTERRUPT_FP_UNAVAIL
81 KVM_HANDLER BOOKE_INTERRUPT_SYSCALL
82 KVM_HANDLERBOOKE_INTERRUPT_AP_UNAVAIL
83 KVM_HANDLERBOOKE_INTERRUPT_DECREMENTER
84 KVM_HANDLER BOOKE_INTERRUPT_FIT
85 KVM_HANDLERBOOKE_INTERRUPT_WATCHDOG
86 KVM_HANDLERBOOKE_INTERRUPT_DTLB_MISS
87 KVM_HANDLERBOOKE_INTERRUPT_ITLB_MISS
88 KVM_HANDLER BOOKE_INTERRUPT_DEBUG
89 KVM_HANDLERBOOKE_INTERRUPT_SPE_UNAVAIL
90 KVM_HANDLERBOOKE_INTERRUPT_SPE_FP_DATA
91 KVM_HANDLERBOOKE_INTERRUPT_SPE_FP_ROUND
92
93 _GLOBAL(kvmppc_handler_len)
94 .long kvmppc_handler_1 - kvmppc_handler_0
在kvm初始化时将kvmppc_handlers_start内容拷贝到kvmppc_booke_handlers中，例如
rch/powerpc/kvm/e500.c的kvmppc_e500_init中
149
150 ivor[0] =mfspr(SPRN_IVOR32);
151 ivor[1] =mfspr(SPRN_IVOR33);
152 ivor[2] =mfspr(SPRN_IVOR34);
153 for (i = 0; i< 3; i++) {
154 if (ivor[i] > max_ivor)
155 max_ivor =ivor[i];
156
157 memcpy((void *)kvmppc_booke_handlers +ivor[i],
158 kvmppc_handlers_start + (i +16) * kvmppc_handler_len,
159 kvmppc_handler_len);
160 }
和arch/powerpc/kvm/booke.c的kvmppc_booke_init函数：
588
590 ivor[0] =mfspr(SPRN_IVOR0);
591 ivor[1] =mfspr(SPRN_IVOR1);
592 ivor[2] =mfspr(SPRN_IVOR2);
593 ivor[3] =mfspr(SPRN_IVOR3);
594 ivor[4] =mfspr(SPRN_IVOR4);
595 ivor[5] =mfspr(SPRN_IVOR5);
596 ivor[6] =mfspr(SPRN_IVOR6);
597 ivor[7] =mfspr(SPRN_IVOR7);
598 ivor[8] =mfspr(SPRN_IVOR8);
599 ivor[9] =mfspr(SPRN_IVOR9);
600 ivor[10] =mfspr(SPRN_IVOR10);
601 ivor[11] =mfspr(SPRN_IVOR11);
602 ivor[12] =mfspr(SPRN_IVOR12);
603 ivor[13] =mfspr(SPRN_IVOR13);
604 ivor[14] =mfspr(SPRN_IVOR14);
605 ivor[15] =mfspr(SPRN_IVOR15);
606
607 for (i = 0; i< 16; i++) {
608 if (ivor[i] > max_ivor)
609 max_ivor =ivor[i];
610
611 memcpy((void *)kvmppc_booke_handlers +ivor[i],
612 kvmppc_handlers_start + i *kvmppc_handler_len,
613 kvmppc_handler_len);
614 }
这两个地方将kvmppc_handlers_start代码拷贝到kvmppc_booke_handlers中
kvmppc_booke_handlers 在__kvmppc_vcpu_run中告知cpu
__kvmppc_vcpu_run使得cpu进入guest执行状态