/* linux_boot.c — VMCS configuration and vmlaunch for Linux 6.6 guest. * * Configures the VMCS guest state for 64-bit Linux entry (startup_64): * - RIP = kernel 64-bit entry point * - RSI = boot_params GPA (Linux calling convention) * - RSP = guest stack top * - CR3 = guest page tables GPA (identity-mapped 4GB) * - GDT = guest GDT GPA (64-bit code/data/TSS) * - EFER.LME | EFER.LMA | EFER.NXE * * After vmlaunch, the VM-Exit handler (vmexit.c) processes exits and * resumes the guest. */ #include #include #include #include #include #include #include #include "../arch/x86_64/limine.h" extern volatile struct limine_hhdm_request g_hhdm_request; /* VM-Exit assembly entry and C dispatcher (from vmm.c / vmexit_asm.S) */ extern void vmx_vm_exit_handler(void); extern int vmexit_dispatch(void); extern u64 vmexit_get_count(void); /* g_saved_host_rsp / g_saved_return_rip / g_guest_terminated / * g_last_exit_reason / g_linux_guest_active / g_guest_parked / * g_guest_regs / g_host_stack 通过 声明（vmm.c 定义）。 */ extern u8 g_host_stack[8192]; /* CR helpers */ static inline u64 read_cr0_local(void) { u64 v; __asm__ volatile("mov %%cr0, %0" : "=r"(v)); return v; } static inline u64 read_cr3_local(void) { u64 v; __asm__ volatile("mov %%cr3, %0" : "=r"(v)); return v; } static inline u64 read_cr4_local(void) { u64 v; __asm__ volatile("mov %%cr4, %0" : "=r"(v)); return v; } static u64 vmx_adjust_control(u64 value, u32 msr) { u32 allowed0 = (u32)vmx_read_msr(msr); u32 allowed1 = (u32)(vmx_read_msr(msr) >> 32); u32 adjusted = (u32)value | allowed0; adjusted &= allowed1; return adjusted; } /* MSR bitmap (4KB, all zeros = don't intercept any MSR) */ static u8 g_linux_msr_bitmap[4096] __attribute__((aligned(4096))); /* ===== VMCS host state (same as vmm.c, but for Linux guest) ===== */ static void linux_vmcs_setup_host_state(void) { vmx_vmcs_write(VMCS_HOST_CR0, read_cr0_local() | CR0_PE | CR0_NE | CR0_PG); vmx_vmcs_write(VMCS_HOST_CR3, read_cr3_local()); vmx_vmcs_write(VMCS_HOST_CR4, read_cr4_local() | CR4_VMXE); /* Host segment selectors: UTSM GDT 0x08 (code) / 0x10 (data) */ vmx_vmcs_write(VMCS_HOST_CS_SELECTOR, 0x08); vmx_vmcs_write(VMCS_HOST_SS_SELECTOR, 0x10); vmx_vmcs_write(VMCS_HOST_DS_SELECTOR, 0x10); vmx_vmcs_write(VMCS_HOST_ES_SELECTOR, 0x10); vmx_vmcs_write(VMCS_HOST_FS_SELECTOR, 0); vmx_vmcs_write(VMCS_HOST_GS_SELECTOR, 0); vmx_vmcs_write(VMCS_HOST_FS_BASE, 0); vmx_vmcs_write(VMCS_HOST_GS_BASE, 0); /* Host GDT/IDT + TR */ { struct __attribute__((packed)) { u16 limit; u64 base; } gdtr, idtr; __asm__ volatile("sgdt %0" : "=m"(gdtr)); __asm__ volatile("sidt %0" : "=m"(idtr)); vmx_vmcs_write(VMCS_HOST_GDTR_BASE, gdtr.base); vmx_vmcs_write(VMCS_HOST_IDTR_BASE, idtr.base); u16 tr_sel; u64 tr_base; __asm__ volatile("str %0" : "=r"(tr_sel)); u64 gdt_base = gdtr.base; u64 *tss_desc = (u64 *)(gdt_base + (tr_sel & 0xFFF8)); u64 low = tss_desc[0]; u64 high = tss_desc[1]; tr_base = (low >> 16) & 0xFFFFFF; tr_base |= ((low >> 32) & 0xFF) << 24; tr_base |= (high & 0xFFFFFFFF) << 32; vmx_vmcs_write(VMCS_HOST_TR_SELECTOR, tr_sel); vmx_vmcs_write(VMCS_HOST_TR_BASE, tr_base); } /* Host SYSENTER */ { u64 sysenter_cs; __asm__ volatile("rdmsr" : "=a"(sysenter_cs) : "c"(0x174)); vmx_vmcs_write(VMCS_HOST_SYSENTER_CS, sysenter_cs & 0xFFFFFFFF); vmx_vmcs_write(VMCS_HOST_SYSENTER_ESP, 0); vmx_vmcs_write(VMCS_HOST_SYSENTER_EIP, 0); } /* Host EFER */ { u32 low, high; __asm__ volatile("rdmsr" : "=a"(low), "=d"(high) : "c"(0xC0000080)); u64 host_efer = ((u64)high << 32) | low; vmx_vmcs_write(VMCS_HOST_IA32_EFER, host_efer); } /* Host RSP/RIP: VM-Exit handler */ vmx_vmcs_write(VMCS_HOST_RSP, (u64)&g_host_stack[sizeof(g_host_stack) - 16]); vmx_vmcs_write(VMCS_HOST_RIP, (u64)vmx_vm_exit_handler); } /* ===== VMCS guest state for Linux ===== */ static void linux_vmcs_setup_guest_state(const struct linux_guest_info *gi) { /* CR0/CR3/CR4: long mode with paging */ vmx_vmcs_write(VMCS_GUEST_CR0, CR0_PE | CR0_NE | CR0_PG | CR0_WP); /* CR3 points to guest PML4 (GPA) */ vmx_vmcs_write(VMCS_GUEST_CR3, gi->pgt_gpa); vmx_vmcs_write(VMCS_GUEST_CR4, CR4_PAE | CR4_PGE | CR4_PSE); /* Segment selectors from guest GDT */ vmx_vmcs_write(VMCS_GUEST_CS_SELECTOR, 0x08); vmx_vmcs_write(VMCS_GUEST_SS_SELECTOR, 0x10); vmx_vmcs_write(VMCS_GUEST_DS_SELECTOR, 0x10); vmx_vmcs_write(VMCS_GUEST_ES_SELECTOR, 0x10); vmx_vmcs_write(VMCS_GUEST_FS_SELECTOR, 0); vmx_vmcs_write(VMCS_GUEST_GS_SELECTOR, 0); vmx_vmcs_write(VMCS_GUEST_LDTR_SELECTOR, 0); vmx_vmcs_write(VMCS_GUEST_TR_SELECTOR, 0x18); /* Segment bases: flat model, TR points to TSS in GDT page */ vmx_vmcs_write(VMCS_GUEST_CS_BASE, 0); vmx_vmcs_write(VMCS_GUEST_SS_BASE, 0); vmx_vmcs_write(VMCS_GUEST_DS_BASE, 0); vmx_vmcs_write(VMCS_GUEST_ES_BASE, 0); vmx_vmcs_write(VMCS_GUEST_FS_BASE, 0); vmx_vmcs_write(VMCS_GUEST_GS_BASE, 0); vmx_vmcs_write(VMCS_GUEST_LDTR_BASE, 0); vmx_vmcs_write(VMCS_GUEST_TR_BASE, gi->gdt_gpa + 0x100); vmx_vmcs_write(VMCS_GUEST_GDTR_BASE, gi->gdt_gpa); vmx_vmcs_write(VMCS_GUEST_IDTR_BASE, 0); /* Segment limits */ vmx_vmcs_write(VMCS_GUEST_CS_LIMIT, 0xFFFFFFFF); vmx_vmcs_write(VMCS_GUEST_SS_LIMIT, 0xFFFFFFFF); vmx_vmcs_write(VMCS_GUEST_DS_LIMIT, 0xFFFFFFFF); vmx_vmcs_write(VMCS_GUEST_ES_LIMIT, 0xFFFFFFFF); vmx_vmcs_write(VMCS_GUEST_FS_LIMIT, 0xFFFFFFFF); vmx_vmcs_write(VMCS_GUEST_GS_LIMIT, 0xFFFFFFFF); vmx_vmcs_write(VMCS_GUEST_LDTR_LIMIT, 0xFFFF); vmx_vmcs_write(VMCS_GUEST_TR_LIMIT, 0x67); vmx_vmcs_write(VMCS_GUEST_GDTR_LIMIT, 0x28); vmx_vmcs_write(VMCS_GUEST_IDTR_LIMIT, 0xFFFF); /* Access rights */ vmx_vmcs_write(VMCS_GUEST_CS_ACCESS, 0xA09B); /* 64-bit code, L=1 */ vmx_vmcs_write(VMCS_GUEST_SS_ACCESS, 0xC093); vmx_vmcs_write(VMCS_GUEST_DS_ACCESS, 0xC093); vmx_vmcs_write(VMCS_GUEST_ES_ACCESS, 0xC093); vmx_vmcs_write(VMCS_GUEST_FS_ACCESS, 0xC093); vmx_vmcs_write(VMCS_GUEST_GS_ACCESS, 0xC093); vmx_vmcs_write(VMCS_GUEST_LDTR_ACCESS, 0x82); /* unusable */ vmx_vmcs_write(VMCS_GUEST_TR_ACCESS, 0x8B); /* busy 64-bit TSS */ /* Guest RIP = Linux 64-bit entry (startup_64) */ vmx_vmcs_write(VMCS_GUEST_RIP, gi->kernel_entry); /* Guest RSP = top of stack page */ vmx_vmcs_write(VMCS_GUEST_RSP, LINUX_GUEST_STACK_GPA + 0x1000); /* NOTE: RSI (boot_params address) is NOT a VMCS field. * VMX does not save/restore GPRs (RAX-R15) in VMCS. * RSI is set via the inline asm launch stub in linux_launch(). */ vmx_vmcs_write(VMCS_GUEST_RFLAGS, 0x2); /* interrupts disabled */ /* Guest EFER: long mode active */ vmx_vmcs_write(VMCS_GUEST_IA32_EFER, EFER_LME | EFER_LMA | EFER_NXE); /* Guest SYSENTER (unused but required by VMX) */ vmx_vmcs_write(VMCS_GUEST_SYSENTER_CS, 0); vmx_vmcs_write(VMCS_GUEST_SYSENTER_ESP, 0); vmx_vmcs_write(VMCS_GUEST_SYSENTER_EIP, 0); /* Guest DR7, activity state, interruptibility */ vmx_vmcs_write(VMCS_GUEST_DR7, 0x400); vmx_vmcs_write(VMCS_GUEST_ACTIVITY_STATE, 0); vmx_vmcs_write(VMCS_GUEST_INTERRUPTIBILITY, 0); } /* ===== VMCS controls for Linux ===== */ static void linux_vmcs_setup_controls(u64 eptp) { /* Pin-based：外部中断 exit + NMI exit + VMX preemption timer（若支持）。 * preemption timer 提供 1ms 周期 exit，用于轮询 host 串口 RX、 * 推进 guest PIT tick、注入 pending virtio/COM1 IRQ。 */ u64 pin_want = PIN_EXT_INTERRUPT_EXITING | PIN_NMI_EXITING; if (vmx_preemption_timer_supported()) { pin_want |= PIN_VMX_PREEMPTION_TIMER; } u64 pin = vmx_adjust_control(pin_want, IA32_VMX_TRUE_PINBASED_CTLS); /* CPU-based: exit on HLT, INVLPG, MWAIT, IO, use MSR bitmap, * activate secondary controls. Don't intercept RDTSC (Linux needs it). */ u64 cpu = CPU_BASED_HLT_EXITING | CPU_BASED_ACTIVATE_SECONDARY | CPU_BASED_USE_MSR_BITMAPS | CPU_BASED_UNCOND_IO_EXITING | CPU_BASED_INVLPG_EXITING; cpu = vmx_adjust_control(cpu, IA32_VMX_TRUE_PROCBASED_CTLS); /* Secondary: EPT + VPID */ u64 cpu2 = SEC_EXEC_ENABLE_EPT | SEC_EXEC_ENABLE_VPID; { u64 msr = vmx_read_msr(IA32_VMX_PROCBASED_CTLS2); u32 allowed1 = (u32)(msr >> 32); cpu2 &= allowed1; cpu2 |= SEC_EXEC_ENABLE_EPT; } u64 exit_ctrl = VM_EXIT_SAVE_DEBUG_CONTROLS | VM_EXIT_HOST_ADDR_SPACE_SIZE | VM_EXIT_LOAD_HOST_EFER; exit_ctrl = vmx_adjust_control(exit_ctrl, IA32_VMX_TRUE_EXIT_CTLS); u64 entry_ctrl = VM_ENTRY_LOAD_DEBUG_CONTROLS | VM_ENTRY_IA32E_MODE_GUEST | VM_ENTRY_LOAD_GUEST_EFER; entry_ctrl = vmx_adjust_control(entry_ctrl, IA32_VMX_TRUE_ENTRY_CTLS); vmx_vmcs_write(VMCS_PIN_BASED_VM_EXEC_CONTROL, pin); vmx_vmcs_write(VMCS_CPU_BASED_VM_EXEC_CONTROL, cpu); vmx_vmcs_write(VMCS_SECONDARY_VM_EXEC_CONTROL, cpu2); vmx_vmcs_write(VMCS_VM_EXIT_CONTROLS, exit_ctrl); vmx_vmcs_write(VMCS_VM_ENTRY_CONTROLS, entry_ctrl); /* MSR bitmap */ { u64 hhdm = g_hhdm_request.response ? g_hhdm_request.response->offset : 0; u64 msr_bitmap_phys = (u64)g_linux_msr_bitmap - hhdm; vmx_vmcs_write(VMCS_MSR_BITMAP, msr_bitmap_phys); } vmx_vmcs_write(VMCS_EPT_POINTER, eptp); vmx_vmcs_write(VMCS_VPID, 2); /* VPID 1 = self-test, VPID 2 = Linux */ /* Exception bitmap: catch #GP, #PF, #UD, #DF (triple fault handled separately) */ vmx_vmcs_write(VMCS_EXCEPTION_BITMAP, (1ULL << 13) | (1ULL << 14) | (1ULL << 6) | (1ULL << 8)); } /* ===== Global for passing RSI to launch asm ===== */ static volatile u64 g_linux_rsi; /* ===== Linux launch ===== * * This function is called after vmm_init() + linux_loader_init(). * It configures the VMCS for the Linux guest and performs vmlaunch. * * NOTE: VMX general registers (RAX-R15) are NOT saved in VMCS. * We use inline assembly to set RSI = boot_params GPA before vmlaunch. * * Returns 0 on successful guest termination, negative on error. */ int linux_launch(void) { const struct linux_guest_info *gi = linux_get_guest_info(); if (!gi || !gi->loaded) { log_error("[LINUX] guest not loaded"); return -1; } if (!vmm_is_ready()) { log_error("[LINUX] VMM not ready"); return -2; } log_info("[LINUX] launch begin"); /* 注册 virtio-mmio 后端（block + net），guest 经 cmdline * virtio_mmio.device= 发现。幂等：重复调用直接返回。 */ virtio_mmio_init(); /* 真机 EPT TLB 刷新：在 vmlaunch 前确保 EPT 映射对 TLB 可见 */ ept_flush_ept(); /* Reset VM-Exit state */ g_guest_terminated = 0; g_last_exit_reason = 0xFFFFFFFFULL; g_linux_guest_active = 1; /* 标记当前 guest 为 Linux（HLT 时 park） */ g_guest_parked = 0; /* Configure VMCS */ linux_vmcs_setup_guest_state(gi); linux_vmcs_setup_controls(vmm_get_eptp()); linux_vmcs_setup_host_state(); /* 初始 arm preemption timer（1ms 后首次周期 exit） */ vmx_vmcs_write(VMCS_GUEST_PREEMPTION_TIMER, vmx_preemption_quantum_1ms()); /* Set RSI for Linux boot_params (passed via global, loaded in asm) */ g_linux_rsi = gi->bootparams_gpa; log_hex64("[LINUX] RIP=", gi->kernel_entry); log_hex64("[LINUX] RSP=", LINUX_GUEST_STACK_GPA + 0x1000); log_hex64("[LINUX] RSI=", gi->bootparams_gpa); log_hex64("[LINUX] CR3=", gi->pgt_gpa); log_hex64("[LINUX] GDTR=", gi->gdt_gpa); log_info("[LINUX] vmlaunch"); /* vmlaunch with RSI = boot_params. * Same control flow pattern as vmm_self_test: * - On failure: failed=1, falls through * - On success: enters guest, VM-Exit → vmx_vm_exit_handler * - On terminate: handler restores RSP, jmps to post_guest label */ int failed; __asm__ volatile( "movq %%rsp, g_saved_host_rsp(%%rip)\n\t" "leaq 1f(%%rip), %%rax\n\t" "movq %%rax, g_saved_return_rip(%%rip)\n\t" "movq g_linux_rsi(%%rip), %%rsi\n\t" /* RSI = boot_params GPA */ "vmlaunch\n\t" /* ---- failure path ---- */ "movl $1, %0\n\t" "jmp 2f\n\t" /* ---- post_guest: terminate path jmps here ---- */ "1:\n\t" "movl $0, %0\n\t" "2:\n\t" : "=r"(failed) :: "rax", "rcx", "rdx", "rsi", "rdi", "r8", "r9", "r10", "r11", "memory" ); if (failed) { u64 error = vmx_vmcs_read(VMCS_VMX_INSTRUCTION_ERROR); log_hex64("[LINUX] vmlaunch failed, error=", error); g_linux_guest_active = 0; return -3; } /* Guest parked (HLT) — Linux daemon 已驻留，等待 linux_resume() 唤醒 */ g_linux_guest_active = 0; /* 回到 host 上下文，清除 active 标志 */ g_guest_parked = 1; /* 标记 guest 已 park，linux_resume() 可唤醒 */ log_info("[LINUX] guest parked (daemon ready)"); log_hex64("[LINUX] last exit reason=", g_last_exit_reason); log_hex64("[LINUX] vmexit count=", vmexit_get_count()); return 0; }