On Fri, Mar 12, 2021 at 01:44:58PM -0800, Sean Christopherson wrote: > On Tue, Mar 09, 2021, 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> > > 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 44fe91a5bfb3..8c922e68274d 100644 > > --- a/arch/x86/kernel/cpu/sgx/main.c > > +++ b/arch/x86/kernel/cpu/sgx/main.c > > @@ -712,7 +712,15 @@ 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(); > > I love this code. > > Reviewed-by: Sean Christopherson <seanjc@xxxxxxxxxx> I'm still wondering why this code let's go through when sgx_drv_init() succeeds and sgx_vepc_init() fails. The inline comment explains only the mirrored case (which does make sense). /Jarkko
