Add references for hugepages and booting steps for Arm64. Include info about the current supported architectures for the NE kernel driver. Changelog v1 -> v2 * Add information about supported architectures for the NE kernel driver. Signed-off-by: Andra Paraschiv <andraprs@xxxxxxxxxx> --- Documentation/virt/ne_overview.rst | 21 +++++++++++++-------- 1 file changed, 13 insertions(+), 8 deletions(-) diff --git a/Documentation/virt/ne_overview.rst b/Documentation/virt/ne_overview.rst index 39b0c8fe2654a..74c2f5919c886 100644 --- a/Documentation/virt/ne_overview.rst +++ b/Documentation/virt/ne_overview.rst @@ -14,12 +14,15 @@ instances [1]. For example, an application that processes sensitive data and runs in a VM, can be separated from other applications running in the same VM. This application then runs in a separate VM than the primary VM, namely an enclave. +It runs alongside the VM that spawned it. This setup matches low latency +applications needs. -An enclave runs alongside the VM that spawned it. This setup matches low latency -applications needs. The resources that are allocated for the enclave, such as -memory and CPUs, are carved out of the primary VM. Each enclave is mapped to a -process running in the primary VM, that communicates with the NE driver via an -ioctl interface. +The current supported architectures for the NE kernel driver, available in the +upstream Linux kernel, are x86 and ARM64. + +The resources that are allocated for the enclave, such as memory and CPUs, are +carved out of the primary VM. Each enclave is mapped to a process running in the +primary VM, that communicates with the NE kernel driver via an ioctl interface. In this sense, there are two components: @@ -43,8 +46,8 @@ for the enclave VM. An enclave does not have persistent storage attached. The memory regions carved out of the primary VM and given to an enclave need to be aligned 2 MiB / 1 GiB physically contiguous memory regions (or multiple of this size e.g. 8 MiB). The memory can be allocated e.g. by using hugetlbfs from -user space [2][3]. The memory size for an enclave needs to be at least 64 MiB. -The enclave memory and CPUs need to be from the same NUMA node. +user space [2][3][7]. The memory size for an enclave needs to be at least +64 MiB. The enclave memory and CPUs need to be from the same NUMA node. An enclave runs on dedicated cores. CPU 0 and its CPU siblings need to remain available for the primary VM. A CPU pool has to be set for NE purposes by an @@ -61,7 +64,7 @@ device is placed in memory below the typical 4 GiB. The application that runs in the enclave needs to be packaged in an enclave image together with the OS ( e.g. kernel, ramdisk, init ) that will run in the enclave VM. The enclave VM has its own kernel and follows the standard Linux -boot protocol [6]. +boot protocol [6][8]. The kernel bzImage, the kernel command line, the ramdisk(s) are part of the Enclave Image Format (EIF); plus an EIF header including metadata such as magic @@ -93,3 +96,5 @@ enclave process can exit. [4] https://www.kernel.org/doc/html/latest/admin-guide/kernel-parameters.html [5] https://man7.org/linux/man-pages/man7/vsock.7.html [6] https://www.kernel.org/doc/html/latest/x86/boot.html +[7] https://www.kernel.org/doc/html/latest/arm64/hugetlbpage.html +[8] https://www.kernel.org/doc/html/latest/arm64/booting.html -- 2.20.1 (Apple Git-117) Amazon Development Center (Romania) S.R.L. registered office: 27A Sf. Lazar Street, UBC5, floor 2, Iasi, Iasi County, 700045, Romania. Registered in Romania. Registration number J22/2621/2005.
