Re: [PATCH v36 07/24] x86/cpu/intel: Add nosgx kernel parameter

[Darren Kenny]

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 
> Reviewed-by: Sean Christopherson 
> Signed-off-by: Jarkko Sakkinen 

Reviewed-by: Darren Kenny 

> ---
>  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

[PATCH v36 07/24] x86/cpu/intel: Add nosgx kernel parameter

[Jarkko Sakkinen]

Add kernel parameter to disable Intel SGX kernel support.

Tested-by: Sean Christopherson 
Reviewed-by: Sean Christopherson 
Signed-off-by: Jarkko Sakkinen 
---
 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