[KVM] VMCS
About
VMCS は Virtual Machine Control Structure の略で VM の様々な情報を保持している．
以下では Linux (KVM) における VMCS の内容などについてメモする．
VM Excution Control
VM execution control は VM exit するかどうか指定するためのフィールド．下記のファイルのコメントを見るとフラグの意味が比較的わかりやすい．
- arch/x86/include/asm/vmxfeatures.h
実際にそのフラグが存在するかなどを確認する際には arch/x86/include/asm/vmx.h のフラグを用いるらしい．
vmcs_config 内の変数 {pin,cpu}_based_exec_ctrl に現在の値が格納されているので，arch/x86/include/asm/vmx.h のフラグと比較すれば確認できる．
struct vmcs_config {
int size;
int order;
u32 basic_cap;
u32 revision_id;
u32 pin_based_exec_ctrl;
u32 cpu_based_exec_ctrl;
u32 cpu_based_2nd_exec_ctrl;
u32 vmexit_ctrl;
u32 vmentry_ctrl;
struct nested_vmx_msrs nested;
};
参考
- arch/x86/kvm/vmx/vmx.c
u32 vmx_exec_control(struct vcpu_vmx *vmx)
{
u32 exec_control = vmcs_config.cpu_based_exec_ctrl;
if (vmx->vcpu.arch.switch_db_regs & KVM_DEBUGREG_WONT_EXIT)
exec_control &= ~CPU_BASED_MOV_DR_EXITING;
if (!cpu_need_tpr_shadow(&vmx->vcpu)) {
exec_control &= ~CPU_BASED_TPR_SHADOW;
#ifdef CONFIG_X86_64
exec_control |= CPU_BASED_CR8_STORE_EXITING |
CPU_BASED_CR8_LOAD_EXITING;
#endif
}
if (!enable_ept)
exec_control |= CPU_BASED_CR3_STORE_EXITING |
CPU_BASED_CR3_LOAD_EXITING |
CPU_BASED_INVLPG_EXITING;
if (kvm_mwait_in_guest(vmx->vcpu.kvm))
exec_control &= ~(CPU_BASED_MWAIT_EXITING |
CPU_BASED_MONITOR_EXITING);
if (kvm_hlt_in_guest(vmx->vcpu.kvm))
exec_control &= ~CPU_BASED_HLT_EXITING;
return exec_control;
}
Data Structures
enum vmcs_field
- arch/x86/include/asm/vmx.h
/* VMCS Encodings */
enum vmcs_field {
VIRTUAL_PROCESSOR_ID = 0x00000000,
POSTED_INTR_NV = 0x00000002,
GUEST_ES_SELECTOR = 0x00000800,
GUEST_CS_SELECTOR = 0x00000802,
GUEST_SS_SELECTOR = 0x00000804,
GUEST_DS_SELECTOR = 0x00000806,
GUEST_FS_SELECTOR = 0x00000808,
GUEST_GS_SELECTOR = 0x0000080a,
GUEST_LDTR_SELECTOR = 0x0000080c,
GUEST_TR_SELECTOR = 0x0000080e,
GUEST_INTR_STATUS = 0x00000810,
GUEST_PML_INDEX = 0x00000812,
HOST_ES_SELECTOR = 0x00000c00,
HOST_CS_SELECTOR = 0x00000c02,
HOST_SS_SELECTOR = 0x00000c04,
HOST_DS_SELECTOR = 0x00000c06,
HOST_FS_SELECTOR = 0x00000c08,
HOST_GS_SELECTOR = 0x00000c0a,
HOST_TR_SELECTOR = 0x00000c0c,
IO_BITMAP_A = 0x00002000,
IO_BITMAP_A_HIGH = 0x00002001,
IO_BITMAP_B = 0x00002002,
IO_BITMAP_B_HIGH = 0x00002003,
MSR_BITMAP = 0x00002004,
MSR_BITMAP_HIGH = 0x00002005,
VM_EXIT_MSR_STORE_ADDR = 0x00002006,
VM_EXIT_MSR_STORE_ADDR_HIGH = 0x00002007,
VM_EXIT_MSR_LOAD_ADDR = 0x00002008,
VM_EXIT_MSR_LOAD_ADDR_HIGH = 0x00002009,
VM_ENTRY_MSR_LOAD_ADDR = 0x0000200a,
VM_ENTRY_MSR_LOAD_ADDR_HIGH = 0x0000200b,
PML_ADDRESS = 0x0000200e,
PML_ADDRESS_HIGH = 0x0000200f,
TSC_OFFSET = 0x00002010,
TSC_OFFSET_HIGH = 0x00002011,
VIRTUAL_APIC_PAGE_ADDR = 0x00002012,
VIRTUAL_APIC_PAGE_ADDR_HIGH = 0x00002013,
APIC_ACCESS_ADDR = 0x00002014,
APIC_ACCESS_ADDR_HIGH = 0x00002015,
POSTED_INTR_DESC_ADDR = 0x00002016,
POSTED_INTR_DESC_ADDR_HIGH = 0x00002017,
VM_FUNCTION_CONTROL = 0x00002018,
VM_FUNCTION_CONTROL_HIGH = 0x00002019,
EPT_POINTER = 0x0000201a,
EPT_POINTER_HIGH = 0x0000201b,
EOI_EXIT_BITMAP0 = 0x0000201c,
EOI_EXIT_BITMAP0_HIGH = 0x0000201d,
EOI_EXIT_BITMAP1 = 0x0000201e,
EOI_EXIT_BITMAP1_HIGH = 0x0000201f,
EOI_EXIT_BITMAP2 = 0x00002020,
EOI_EXIT_BITMAP2_HIGH = 0x00002021,
EOI_EXIT_BITMAP3 = 0x00002022,
EOI_EXIT_BITMAP3_HIGH = 0x00002023,
EPTP_LIST_ADDRESS = 0x00002024,
EPTP_LIST_ADDRESS_HIGH = 0x00002025,
VMREAD_BITMAP = 0x00002026,
VMREAD_BITMAP_HIGH = 0x00002027,
VMWRITE_BITMAP = 0x00002028,
VMWRITE_BITMAP_HIGH = 0x00002029,
XSS_EXIT_BITMAP = 0x0000202C,
XSS_EXIT_BITMAP_HIGH = 0x0000202D,
ENCLS_EXITING_BITMAP = 0x0000202E,
ENCLS_EXITING_BITMAP_HIGH = 0x0000202F,
TSC_MULTIPLIER = 0x00002032,
TSC_MULTIPLIER_HIGH = 0x00002033,
GUEST_PHYSICAL_ADDRESS = 0x00002400,
GUEST_PHYSICAL_ADDRESS_HIGH = 0x00002401,
VMCS_LINK_POINTER = 0x00002800,
VMCS_LINK_POINTER_HIGH = 0x00002801,
GUEST_IA32_DEBUGCTL = 0x00002802,
GUEST_IA32_DEBUGCTL_HIGH = 0x00002803,
GUEST_IA32_PAT = 0x00002804,
GUEST_IA32_PAT_HIGH = 0x00002805,
GUEST_IA32_EFER = 0x00002806,
GUEST_IA32_EFER_HIGH = 0x00002807,
GUEST_IA32_PERF_GLOBAL_CTRL = 0x00002808,
GUEST_IA32_PERF_GLOBAL_CTRL_HIGH= 0x00002809,
GUEST_PDPTR0 = 0x0000280a,
GUEST_PDPTR0_HIGH = 0x0000280b,
GUEST_PDPTR1 = 0x0000280c,
GUEST_PDPTR1_HIGH = 0x0000280d,
GUEST_PDPTR2 = 0x0000280e,
GUEST_PDPTR2_HIGH = 0x0000280f,
GUEST_PDPTR3 = 0x00002810,
GUEST_PDPTR3_HIGH = 0x00002811,
GUEST_BNDCFGS = 0x00002812,
GUEST_BNDCFGS_HIGH = 0x00002813,
GUEST_IA32_RTIT_CTL = 0x00002814,
GUEST_IA32_RTIT_CTL_HIGH = 0x00002815,
HOST_IA32_PAT = 0x00002c00,
HOST_IA32_PAT_HIGH = 0x00002c01,
HOST_IA32_EFER = 0x00002c02,
HOST_IA32_EFER_HIGH = 0x00002c03,
HOST_IA32_PERF_GLOBAL_CTRL = 0x00002c04,
HOST_IA32_PERF_GLOBAL_CTRL_HIGH = 0x00002c05,
PIN_BASED_VM_EXEC_CONTROL = 0x00004000,
CPU_BASED_VM_EXEC_CONTROL = 0x00004002,
EXCEPTION_BITMAP = 0x00004004,
PAGE_FAULT_ERROR_CODE_MASK = 0x00004006,
PAGE_FAULT_ERROR_CODE_MATCH = 0x00004008,
CR3_TARGET_COUNT = 0x0000400a,
VM_EXIT_CONTROLS = 0x0000400c,
VM_EXIT_MSR_STORE_COUNT = 0x0000400e,
VM_EXIT_MSR_LOAD_COUNT = 0x00004010,
VM_ENTRY_CONTROLS = 0x00004012,
VM_ENTRY_MSR_LOAD_COUNT = 0x00004014,
VM_ENTRY_INTR_INFO_FIELD = 0x00004016,
VM_ENTRY_EXCEPTION_ERROR_CODE = 0x00004018,
VM_ENTRY_INSTRUCTION_LEN = 0x0000401a,
TPR_THRESHOLD = 0x0000401c,
SECONDARY_VM_EXEC_CONTROL = 0x0000401e,
PLE_GAP = 0x00004020,
PLE_WINDOW = 0x00004022,
VM_INSTRUCTION_ERROR = 0x00004400,
VM_EXIT_REASON = 0x00004402,
VM_EXIT_INTR_INFO = 0x00004404,
VM_EXIT_INTR_ERROR_CODE = 0x00004406,
IDT_VECTORING_INFO_FIELD = 0x00004408,
IDT_VECTORING_ERROR_CODE = 0x0000440a,
VM_EXIT_INSTRUCTION_LEN = 0x0000440c,
VMX_INSTRUCTION_INFO = 0x0000440e,
GUEST_ES_LIMIT = 0x00004800,
GUEST_CS_LIMIT = 0x00004802,
GUEST_SS_LIMIT = 0x00004804,
GUEST_DS_LIMIT = 0x00004806,
GUEST_FS_LIMIT = 0x00004808,
GUEST_GS_LIMIT = 0x0000480a,
GUEST_LDTR_LIMIT = 0x0000480c,
GUEST_TR_LIMIT = 0x0000480e,
GUEST_GDTR_LIMIT = 0x00004810,
GUEST_IDTR_LIMIT = 0x00004812,
GUEST_ES_AR_BYTES = 0x00004814,
GUEST_CS_AR_BYTES = 0x00004816,
GUEST_SS_AR_BYTES = 0x00004818,
GUEST_DS_AR_BYTES = 0x0000481a,
GUEST_FS_AR_BYTES = 0x0000481c,
GUEST_GS_AR_BYTES = 0x0000481e,
GUEST_LDTR_AR_BYTES = 0x00004820,
GUEST_TR_AR_BYTES = 0x00004822,
GUEST_INTERRUPTIBILITY_INFO = 0x00004824,
GUEST_ACTIVITY_STATE = 0X00004826,
GUEST_SYSENTER_CS = 0x0000482A,
VMX_PREEMPTION_TIMER_VALUE = 0x0000482E,
HOST_IA32_SYSENTER_CS = 0x00004c00,
CR0_GUEST_HOST_MASK = 0x00006000,
CR4_GUEST_HOST_MASK = 0x00006002,
CR0_READ_SHADOW = 0x00006004,
CR4_READ_SHADOW = 0x00006006,
CR3_TARGET_VALUE0 = 0x00006008,
CR3_TARGET_VALUE1 = 0x0000600a,
CR3_TARGET_VALUE2 = 0x0000600c,
CR3_TARGET_VALUE3 = 0x0000600e,
EXIT_QUALIFICATION = 0x00006400,
GUEST_LINEAR_ADDRESS = 0x0000640a,
GUEST_CR0 = 0x00006800,
GUEST_CR3 = 0x00006802,
GUEST_CR4 = 0x00006804,
GUEST_ES_BASE = 0x00006806,
GUEST_CS_BASE = 0x00006808,
GUEST_SS_BASE = 0x0000680a,
GUEST_DS_BASE = 0x0000680c,
GUEST_FS_BASE = 0x0000680e,
GUEST_GS_BASE = 0x00006810,
GUEST_LDTR_BASE = 0x00006812,
GUEST_TR_BASE = 0x00006814,
GUEST_GDTR_BASE = 0x00006816,
GUEST_IDTR_BASE = 0x00006818,
GUEST_DR7 = 0x0000681a,
GUEST_RSP = 0x0000681c,
GUEST_RIP = 0x0000681e,
GUEST_RFLAGS = 0x00006820,
GUEST_PENDING_DBG_EXCEPTIONS = 0x00006822,
GUEST_SYSENTER_ESP = 0x00006824,
GUEST_SYSENTER_EIP = 0x00006826,
HOST_CR0 = 0x00006c00,
HOST_CR3 = 0x00006c02,
HOST_CR4 = 0x00006c04,
HOST_FS_BASE = 0x00006c06,
HOST_GS_BASE = 0x00006c08,
HOST_TR_BASE = 0x00006c0a,
HOST_GDTR_BASE = 0x00006c0c,
HOST_IDTR_BASE = 0x00006c0e,
HOST_IA32_SYSENTER_ESP = 0x00006c10,
HOST_IA32_SYSENTER_EIP = 0x00006c12,
HOST_RSP = 0x00006c14,
HOST_RIP = 0x00006c16,
};