On Thu, Mar 03, 2022 at 10:47:20AM -0600, Brijesh Singh wrote: > I did not fail on !req.cert_len, because my read of the GHCB spec says that > additional data (certificate blob) is optional. A user could call > SNP_GET_EXT_REPORT without asking for the extended certificate. In this > case, SNP_GET_EXT_REPORT == SNP_GET_REPORT. > > Text from the GHCB spec section 4.1.8 > --------------- > https://developer.amd.com/wp-content/resources/56421.pdf > > The SNP Extended Guest Request NAE event is very similar to the SNP Guest > Request NAE event. The difference is related to the additional data that can > be returned based on the guest request. Any SNP Guest Request that does not > support returning additional data must execute as if invoked as an SNP Guest > Request. > -------------- Sorry, it is still not clear to me how "without asking for the extended certificate" == !req.certs_len That's not explained in the help text either. And ->certs_len is part of the input structure but nowhere does it say that when that thing is 0, the request will be downgraded to a SNP_GET_REPORT. How is the user of this supposed to know? And regardless, you can still streamline the code as in the example I gave so that it is clear which values are checked and for which does the request get failed... -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette
