Re: [RFC PATCH v3 08/27] x86/sgx: Initialize virtual EPC driver even when SGX driver is disabled

Jarkko Sakkinen
2021-01-30T14:47:55Z

On Tue, Jan 26, 2021 at 10:31:00PM +1300, Kai Huang wrote:
> Modify sgx_init() to always try to initialize the virtual EPC driver,
> even if the bare-metal SGX driver is disabled. The bare-metal driver
> might be disabled if SGX Launch Control is in locked mode, or not
> supported in the hardware at all. This allows (non-Linux) guests that
> support non-LC configurations to use SGX.
>
> Signed-off-by: Kai Huang <kai.huang@intel.com>
> ---
> v2->v3:
>
> - Changed from sgx_virt_epc_init() to sgx_vepc_init().
>
> ---
> arch/x86/kernel/cpu/sgx/main.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/arch/x86/kernel/cpu/sgx/main.c b/arch/x86/kernel/cpu/sgx/main.c
> index 21c2ffa13870..93d249f7bff3 100644
> --- a/arch/x86/kernel/cpu/sgx/main.c
> +++ b/arch/x86/kernel/cpu/sgx/main.c
> @@ -12,6 +12,7 @@
> #include "driver.h"
> #include "encl.h"
> #include "encls.h"
> +#include "virt.h"
>
> struct sgx_epc_section sgx_epc_sections[SGX_MAX_EPC_SECTIONS];
> static int sgx_nr_epc_sections;
> @@ -712,7 +713,8 @@ static int __init sgx_init(void)
> goto err_page_cache;
> }
>
> - ret = sgx_drv_init();
> + /* Success if the native *or* virtual EPC driver initialized cleanly. */
> + ret = !!sgx_drv_init() & !!sgx_vepc_init();

If would create more dumb code and just add

ret = sgx_vepc_init()
if (ret)
goto err_kthread;

> if (ret)
> goto err_kthread;
>
> --
> 2.29.2
>

/Jarkko
>