x86/cpu: Clarify the error message when BIOS does not support SGX

When SGX is not supported by the BIOS, the kernel log contains the error
'SGX disabled by BIOS', which can be confusing since there might not be an
SGX-related option in the BIOS settings.

For the kernel it's difficult to distinguish between the BIOS not
supporting SGX and the BIOS supporting SGX but having it disabled.

Therefore, update the error message to 'SGX disabled or unsupported by
BIOS' to make it easier for those reading kernel logs to understand what's
happening.

Reported-by: Bo Wu <[email protected]>
Co-developed-by: Zelong Xiang <[email protected]>
Signed-off-by: Zelong Xiang <[email protected]>
Signed-off-by: WangYuli <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Acked-by: Kai Huang <[email protected]>
Link: https://lore.kernel.org/all/[email protected]
Closes: linuxdeepin/developer-center#10032

Author: WangYuli

arch/x86/kernel/cpu/feat_ctl.c

@@ -188,7 +188,7 @@ void init_ia32_feat_ctl(struct cpuinfo_x86 *c)
 update_sgx:
 	if (!(msr & FEAT_CTL_SGX_ENABLED)) {
 		if (enable_sgx_kvm || enable_sgx_driver)
-			pr_err_once("SGX disabled by BIOS.\n");
+			pr_err_once("SGX disabled or unsupported by BIOS.\n");
 		clear_cpu_cap(c, X86_FEATURE_SGX);
 		return;
 	}