On Thursday, 2020-07-16 at 16:52:46 +03, Jarkko Sakkinen wrote:
> Add kernel parameter to disable Intel SGX kernel support.
>
> Tested-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>
> Reviewed-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>
> Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@xxxxxxxxxxxxxxx>
Reviewed-by: Darren Kenny <darren.kenny@xxxxxxxxxx>
> ---
> Documentation/admin-guide/kernel-parameters.txt | 2 ++
> arch/x86/kernel/cpu/feat_ctl.c | 9 +++++++++
> 2 files changed, 11 insertions(+)
>
> diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
> index fb95fad81c79..e747bd9ca911 100644
> --- a/Documentation/admin-guide/kernel-parameters.txt
> +++ b/Documentation/admin-guide/kernel-parameters.txt
> @@ -3314,6 +3314,8 @@
>
> nosep [BUGS=X86-32] Disables x86 SYSENTER/SYSEXIT support.
>
> + nosgx [X86-64,SGX] Disables Intel SGX kernel support.
> +
> nosmp [SMP] Tells an SMP kernel to act as a UP kernel,
> and disable the IO APIC. legacy for "maxcpus=0".
>
> diff --git a/arch/x86/kernel/cpu/feat_ctl.c b/arch/x86/kernel/cpu/feat_ctl.c
> index c3afcd2e4342..1837df39527f 100644
> --- a/arch/x86/kernel/cpu/feat_ctl.c
> +++ b/arch/x86/kernel/cpu/feat_ctl.c
> @@ -101,6 +101,15 @@ static void clear_sgx_caps(void)
> setup_clear_cpu_cap(X86_FEATURE_SGX2);
> }
>
> +static int __init nosgx(char *str)
> +{
> + clear_sgx_caps();
> +
> + return 0;
> +}
> +
> +early_param("nosgx", nosgx);
> +
> void init_ia32_feat_ctl(struct cpuinfo_x86 *c)
> {
> bool tboot = tboot_enabled();
> --
> 2.25.1
