Re: [libvirt][PATCH v4 0/4] Support query and use SGX

On Thu, Jul 01, 2021 at 08:10:25PM +0800, Haibin Huang wrote: > This patch series provides support for enabling Intel's Software Guard Extensions (SGX) feature in guest VM. > > Giving the SGX support in QEMU is still pending for reviewing, this patch series is not submmited for code > review, but only describe the SGX enabling solution design that contains changes to virConnectGetDomainCapabilities > API response and domain definition. All comments/suggestions would be highly appreciated. > > Intel Software Guard Extensions (Intel® SGX) is a set of instructions that increases the security of application > code and data, giving them more protection from disclosure or modification. Developers can partition sensitive > information into enclaves, which are areas of execution in memory with more security protection. > > The typical flow looks below at very high level: > > 1. Calls virConnectGetDomainCapabilities API to domain capabilities that includes the following SGX information. > > <feature> > ... > <sgx supported='yes'> > <epc_size unit=’KiB’>N</epc_size> > </sgx> > </feature> > > 2. User requests to start a guest calling virCreateXML() with SGX requirement. > It should contain > > <launchSecurity type='sgx'> > <epc_size unit='KiB'>N</epc_size> > </launchSecurity> I don't think that Intel SGX belongs into <launchSecurity> in libvirt. Similar feature to AMD SEV is Intel TDX which would be implement using <launchSecurity> as it offers isolation between host and VM. Looking at the patches this doesn't even use confidential-guest-support machine option, it adds a new memory backend and enables CPU features only if libvirt uses <cpu mode='custom'> so it would not work with any other CPU mode.

To me this sounds like we should split the feature into two components where one would add support for the new memory backend into correct XML part [1] and the other component would be support for CPU features related to Intel SGX [2].