arch/x86/kernel/cpu/sgx/driver.c

Source file repositories/reference/linux-study-clean/arch/x86/kernel/cpu/sgx/driver.c

File Facts

System
Linux kernel
Corpus path
arch/x86/kernel/cpu/sgx/driver.c
Extension
.c
Size
4530 bytes
Lines
205
Domain
Architecture Layer
Bucket
arch/x86
Inferred role
Architecture Layer: operation-table or driver-model contract
Status
pattern implementation candidate

Why This File Exists

CPU and platform-specific kernel glue: boot entry, traps, syscall entry, interrupts, page tables, context switch, and low-level barriers.

Dependency Surface

Detected Declarations

Annotated Snippet

static const struct file_operations sgx_encl_fops = {
	.owner			= THIS_MODULE,
	.open			= sgx_open,
	.release		= sgx_release,
	.unlocked_ioctl		= sgx_ioctl,
#ifdef CONFIG_COMPAT
	.compat_ioctl		= sgx_compat_ioctl,
#endif
	.mmap			= sgx_mmap,
	.get_unmapped_area	= sgx_get_unmapped_area,
};

static struct miscdevice sgx_dev_enclave = {
	.minor = MISC_DYNAMIC_MINOR,
	.name = "sgx_enclave",
	.nodename = "sgx_enclave",
	.fops = &sgx_encl_fops,
};

int __init sgx_drv_init(void)
{
	unsigned int eax, ebx, ecx, edx;
	u64 attr_mask;
	u64 xfrm_mask;
	int ret;

	if (!cpu_feature_enabled(X86_FEATURE_SGX_LC)) {
		pr_info("SGX disabled: SGX launch control CPU feature is not available, /dev/sgx_enclave disabled.\n");
		return -ENODEV;
	}

	cpuid_count(SGX_CPUID, 0, &eax, &ebx, &ecx, &edx);

	if (!(eax & 1))  {
		pr_info("SGX disabled: SGX1 instruction support not available, /dev/sgx_enclave disabled.\n");
		return -ENODEV;
	}

	sgx_misc_reserved_mask = ~ebx | SGX_MISC_RESERVED_MASK;

	cpuid_count(SGX_CPUID, 1, &eax, &ebx, &ecx, &edx);

	attr_mask = (((u64)ebx) << 32) + (u64)eax;
	sgx_attributes_reserved_mask = ~attr_mask | SGX_ATTR_RESERVED_MASK;

	if (cpu_feature_enabled(X86_FEATURE_OSXSAVE)) {
		xfrm_mask = (((u64)edx) << 32) + (u64)ecx;
		sgx_xfrm_reserved_mask = ~xfrm_mask;
	}

	ret = misc_register(&sgx_dev_enclave);
	if (ret) {
		pr_info("SGX disabled: Unable to register the /dev/sgx_enclave driver (%d).\n", ret);
		return ret;
	}

	return 0;
}

Annotation

Implementation Notes