On Fri, 2 Apr 2021 15:42:51 +0000 Sean Christopherson wrote: > On Fri, Apr 02, 2021, 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@xxxxxxxxx> > > > Reviewed-by: Sean Christopherson <seanjc@xxxxxxxxxx> > > > Signed-off-by: Kai Huang <kai.huang@xxxxxxxxx> > > > --- > > > 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. > > Nope! That's wrong, as sgx_epc_init() will not be called if sgx_drv_init() > succeeds. And writing it as "if (sgx_drv_init() || sgx_vepc_init())" is also > wrong since that would kill SGX when one of the drivers is alive and well. Right. Thanks for pointing out.
