On Tue, 2021-03-02 at 18:53 +0100, Boris Petkov wrote: > On March 2, 2021 5:02:13 PM GMT+01:00, Sean Christopherson <seanjc@xxxxxxxxxx> wrote: > > The KVM use case is to query /proc/cpuinfo to see if sgx2 can be > > enabled in a > > guest. > > You mean before the guest ia created? I sure hope there's a better way to query HV-supported features than grepping /proc/cpuinfo... > > > The counter-argument to that is we might want sgx2 in /proc/cpuinfo to > > mean sgx2 > > is enabled in hardware _and_ supported by the kernel. Userspace can > > grep for > > sgx in /proc/cpuinfo, and use cpuid to discover sgx2, so it's not a > > blocker. > > Question is, what exactly that flag should denote: that EDMM is supported in the HV and guests can do the dynamic thing of adding/rwmoving EPC pages? Is that the only feature behind SGX2? Yes SGX2 == EDMM. Other sub-features, such as VMM oversubscription, have other CPUID bits. > > > That being said, adding some form of capability/versioning to SGX seems > > inevitable, not sure it's worth witholding sgx2 from /proc/cpuinfo. > > See what I typed earlier - no objections from me if a proper use case is identified and written down. > > Thx.
