RE: [libvirt][PATCH v13 0/6] Support query and use SGX

True, QEMU only need read and write access to /dev/sgx_vepc and /dev/sgx_provision. /dev/sgx_vepc allows userspace to allocate "raw" EPC without an associated enclave. The only known use case for raw EPC allocation is to expose EPC to a KVM guest, hence call it 'vepc'. /dev/sgx_enclave allows creating host enclave. It is not suitable for allocating EPC for KVM guest. Having separate device nodes, /dev/sgx_vepc and /dev/sgx_enclave, allows separate permission control for creating host SGX enclaves and KVM SGX guests. /dev/sgx_provision allows creating provisioning enclaves, which typically have more strict permissions than the plain enclave device /dev/sgx_enclave. Usually /dev/sgx_enclave and /dev/sgx_provision should exist together on your system. Set "CONFIG_X86_SGX=y" in Kconfig and enable SGX in bios should enable SGX driver and create /dev/sgx_enclave and /dev/sgx_provision device nodes. "CONFIG_X86_SGX_KVM=y" will create /dev/sgx_vepc device node. Regrading to permission control, one suggested way is making /dev/sgx_enclave is accessible to all userspace applications to create its enclave. Having strict permissions on /dev/sgx_vepc and /dev/sgx_provision only for user in specific group "XYZ". # ls -l /dev/sgx* crw-rw-rw- 1 root root 10, 125 Nov 16 2021 /dev/sgx_enclave crw-rw---- 1 root XYZ 10, 126 Nov 16 2021 /dev/sgx_provision crw-rw---- 1 root XYZ 10, 124 Nov 16 2021 /dev/sgx_vepc Instead of running QEMU by root, one straightforward way is admin create a dedicated "qemu" user and add it to "XYZ" group. In /etc/libvirt/qemu.conf, user = "qemu" Any concerns about this solution? Thanks, Lin.