Re: [PATCH v3 07/25] x86/sgx: Initialize virtual EPC driver even when SGX driver is disabled

Kai Huang
2021-04-02T11:08:18Z

On Fri, 2 Apr 2021 11:48:16 +0200 Borislav Petkov wrote:
> On Fri, Mar 19, 2021 at 08:23:02PM +1300, Kai Huang wrote:
> > Modify sgx_init() to always try to initialize the virtual EPC driver,
> > even if the SGX driver is disabled. The SGX 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.
> >
> > Acked-by: Dave Hansen <dave.hansen@intel.com>
> > Reviewed-by: Sean Christopherson <seanjc@google.com>
> > Signed-off-by: Kai Huang <kai.huang@intel.com>
> > ---
> > arch/x86/kernel/cpu/sgx/main.c | 10 +++++++++-
> > 1 file changed, 9 insertions(+), 1 deletion(-)
> >
> > diff --git a/arch/x86/kernel/cpu/sgx/main.c b/arch/x86/kernel/cpu/sgx/main.c
> > index 6a734f484aa7..b73114150ff8 100644
> > --- a/arch/x86/kernel/cpu/sgx/main.c
> > +++ b/arch/x86/kernel/cpu/sgx/main.c
> > @@ -743,7 +743,15 @@ static int __init sgx_init(void)
> > goto err_page_cache;
> > }
> >
> > - ret = sgx_drv_init();
> > + /*
> > + * Always try to initialize the native *and* KVM drivers.
> > + * The KVM driver is less picky than the native one and
> > + * can function if the native one is not supported on the
> > + * current system or fails to initialize.
> > + *
> > + * Error out only if both fail to initialize.
> > + */
> > + ret = !!sgx_drv_init() & !!sgx_vepc_init();
>
> This is a silly way of writing:
>
> if (sgx_drv_init() && sgx_vepc_init())
> goto err_kthread;
>
> methinks.

Works for me. Thanks.

Do you want me to send updated patch?