On Mon, Oct 19, 2020 at 07:10:58AM -0700, Dave Hansen wrote: > On 10/2/20 9:50 PM, Jarkko Sakkinen wrote: > > > > Add X86_FEATURE_SGX1 and X86_FEATURE_SGX2 from CPUID.(EAX=12H, ECX=0), > > which describe the level of SGX support available [1]. > > The SDM says there are 6 leaf functions added with SGX2 (SDM Vol 3D > Table 36-2): > > ENCLS[EAUG] > ENCLS[EMODPR] > ENCLS[EMODT] > ENCLU[EACCEPT] > ENCLU[EMODPE] > ENCLU[EACCEPTCOPY] > > But I don't see *ANY* of those in use in this patch set. I know we > added a bunch of infrastructure around mitigating if EMODPE got *used*, > but does the kernel need to change its behavior if SGX1 vs. SGX2 is > supported? > > BTW, the SG2 bit is defined: > > Bit 01: SGX2. If 1, Indicates Intel SGX supports the collection > of SGX2 leaf functions. > > which makes me think it's for leaf functions only. As mentioned in the other thread, SGX1 hardware takes an erratum on the #PF behavior of the EPCM, i.e. on SGX2+, EPCM violations generate #PF with PFEC.SGX=1, whereas SGX1 hardware will #GP.
