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Prepare syscall hooking

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This commit is contained in:
momo5502 2024-05-09 16:36:21 +02:00
parent c1d0a354c2
commit 761490c808
1 changed files with 63 additions and 1 deletions
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64
src/driver/hypervisor.cpp
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@ -44,6 +44,12 @@ namespace
return cpuid_data[0] == 'momo';
}
void enable_syscall_hooking()
{
int32_t cpu_info[4]{0};
__cpuidex(cpu_info, 0x41414141, 0x42424243);
}
void cpature_special_registers(vmx::special_registers& special_registers)
{
special_registers.cr0 = __readcr0();
@ -454,13 +460,67 @@ void vmx_handle_invd()
__wbinvd();
}
bool is_system()
{
return (read_vmx(VMCS_GUEST_CS_SELECTOR) & SEGMENT_ACCESS_RIGHTS_DESCRIPTOR_PRIVILEGE_LEVEL_MASK) == DPL_SYSTEM;
}
void set_exception_bit(const exception_vector bit)
{
auto exception_bitmap = read_vmx(VMCS_CTRL_EXCEPTION_BITMAP);
exception_bitmap |= 1ULL << bit;
__vmx_vmwrite(VMCS_CTRL_EXCEPTION_BITMAP, exception_bitmap);
}
void vmx_enable_syscall_hooks()
{
ULARGE_INTEGER msr{};
ia32_efer_register efer_register{};
ia32_vmx_basic_register vmx_basic_register{};
ia32_vmx_exit_ctls_register exit_ctls_register{};
ia32_vmx_entry_ctls_register entry_ctls_register{};
vmx_basic_register.flags = __readmsr(IA32_VMX_BASIC);
exit_ctls_register.flags = read_vmx(VMCS_CTRL_VMEXIT_CONTROLS);
entry_ctls_register.flags = read_vmx(VMCS_CTRL_VMENTRY_CONTROLS);
efer_register.flags = __readmsr(IA32_EFER);
// ---------------------------------------
efer_register.syscall_enable = false;
exit_ctls_register.save_ia32_efer = true;
entry_ctls_register.load_ia32_efer = true;
// ---------------------------------------
msr.QuadPart = __readmsr(vmx_basic_register.vmx_controls ? IA32_VMX_TRUE_ENTRY_CTLS : IA32_VMX_ENTRY_CTLS);
__vmx_vmwrite(VMCS_CTRL_VMENTRY_CONTROLS, adjust_msr(msr, entry_ctls_register.flags));
msr.QuadPart = __readmsr(vmx_basic_register.vmx_controls ? IA32_VMX_TRUE_EXIT_CTLS : IA32_VMX_EXIT_CTLS);
__vmx_vmwrite(VMCS_CTRL_VMEXIT_CONTROLS, adjust_msr(msr, exit_ctls_register.flags));
__vmx_vmwrite(VMCS_GUEST_EFER, efer_register.flags);
set_exception_bit(invalid_opcode);
}
void vmx_handle_cpuid(vmx::guest_context& guest_context)
{
if (guest_context.vp_regs->Rax == 0x41414141 &&
guest_context.vp_regs->Rcx == 0x42424243 &&
is_system())
{
vmx_enable_syscall_hooks();
return;
}
INT32 cpu_info[4];
if (guest_context.vp_regs->Rax == 0x41414141 &&
guest_context.vp_regs->Rcx == 0x42424242 &&
(read_vmx(VMCS_GUEST_CS_SELECTOR) & SEGMENT_ACCESS_RIGHTS_DESCRIPTOR_PRIVILEGE_LEVEL_MASK) == DPL_SYSTEM)
is_system())
{
guest_context.exit_vm = true;
return;
@ -767,6 +827,8 @@ void hypervisor::enable_core(const uint64_t system_directory_table_base)
{
throw std::runtime_error("Hypervisor is not present");
}
enable_syscall_hooking();
}
void hypervisor::disable_core()