[PATCH v4 1/9] docs: geniezone: Introduce GenieZone hypervisor

[Yi-De Wu <yi-de.wu@mediatek.com>]

From: "Yi-De Wu" <yi-de.wu@mediatek.com>

GenieZone is MediaTek proprietary hypervisor solution, and it is running
in EL2 stand alone as a type-I hypervisor. It is a pure EL2
implementation which implies it does not rely any specific host VM, and
this behavior improves GenieZone's security as it limits its interface.

Signed-off-by: Yingshiuan Pan <yingshiuan.pan@mediatek.com>
Signed-off-by: Liju Chen <liju-clr.chen@mediatek.com>
Signed-off-by: Yi-De Wu <yi-de.wu@mediatek.com>
---
 Documentation/virt/geniezone/introduction.rst | 79 +++++++++++++++++++
 MAINTAINERS                                   |  6 ++
 2 files changed, 85 insertions(+)
 create mode 100644 Documentation/virt/geniezone/introduction.rst

diff --git a/Documentation/virt/geniezone/introduction.rst b/Documentation/virt/geniezone/introduction.rst
new file mode 100644
index 000000000000..872c66f60e7f
--- /dev/null
+++ b/Documentation/virt/geniezone/introduction.rst
@@ -0,0 +1,79 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+======================
+GenieZone Introduction
+======================
+
+Overview
+========
+
+GenieZone hypervisor(gzvm) is a type-1 hypervisor that supports various virtual
+machine types and provides security features such as TEE-like scenarios and
+secure boot. It can create guest VMs for security use cases and has
+virtualization capabilities for both platform and interrupt. Although the
+hypervisor can be booted independently, it requires the assistance of GenieZone
+hypervisor kernel driver(gzvm-ko) to leverage the ability of Linux kernel for
+vCPU scheduling, memory management, inter-VM communication and virtio backend
+support.
+
+Supported Architecture
+======================
+
+GenieZone now only supports MediaTek ARM64 SoC.
+
+Features
+========
+
+- vCPU Management
+VM manager aims to provide vCPUs on the basis of time sharing on physical CPUs.
+It requires Linux kernel in host VM for vCPU scheduling and VM power management.
+
+- Memory Management
+Direct use of physical memory from VMs is forbidden and designed to be dictated
+to the privilege models managed by GenieZone hypervisor for security reason.
+With the help of gzvm-ko, the hypervisor would be able to manipulate memory as
+objects.
+
+- Virtual Platform
+We manage to emulate a virtual mobile platform for guest OS running on guest
+VM. The platform supports various architecture-defined devices, such as
+virtual virtual arch timer, GIC, MMIO, PSCI, and exception watching...etc.
+
+- Inter-VM Communication
+Communication among guest VMs was provided mainly on RPC. More communication
+mechanisms were to be provided in the future based on VirtIO-vsock.
+
+- Device Virtualization
+The solution is provided using the well-known VirtIO. The gzvm-ko would
+redirect MMIO traps back to VMM where the virtual devices are mostly emulated.
+Ioeventfd is implemented using eventfd for signaling host VM that some IO
+events in guest VMs need to be processed.
+
+- Interrupt virtualization
+All Interrupts during some guest VMs running would be handled by GenieZone
+hypervisor with the help of gzvm-ko, both virtual and physical ones. In case
+there's no guest VM running out there, physical interrupts would be handled by
+host VM directly for performance reason. Irqfd is also implemented using
+eventfd for accepting vIRQ requests in gzvm-ko.
+
+Platform architecture component
+===============================
+
+- vm
+The vm component is responsible for setting up the capability and memory
+management for the protected VMs. The capability is mainly about the lifecycle
+control and boot context initialization. And the memory management is highly
+integrated with ARM 2-stage translation tables to convert VA to IPA to PA under
+proper security measures required by protected VMs.
+
+- vcpu
+The vcpu component is the core of virtualizing aarch64 physical CPU runnable,
+and it controls the vCPU lifecycle including creating, running and destroying.
+With self-defined exit handler, the vm component would be able to act
+accordingly before terminated.
+
+- vgic
+The vgic component exposes control interfaces to Linux kernel via irqchip, and
+we intend to support all SPI, PPI, and SGI. When it comes to virtual
+interrupts, the GenieZone hypervisor would write to list registers and trigger
+vIRQ injection in guest VMs via GIC.
diff --git a/MAINTAINERS b/MAINTAINERS
index 3a05599017b4..1b1db2073f8b 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -8745,6 +8745,12 @@ F:	include/vdso/
 F:	kernel/time/vsyscall.c
 F:	lib/vdso/
 
+GENIEZONE HYPERVISOR DRIVER
+M:	Yingshiuan Pan <yingshiuan.pan@mediatek.com>
+M:	Ze-Yu Wang <ze-yu.wang@mediatek.com>
+M:	Yi-De Wu <yi-de.wu@mediatek.com>
+F:	Documentation/virt/geniezone/
+
 GENWQE (IBM Generic Workqueue Card)
 M:	Frank Haverkamp <haver@linux.ibm.com>
 S:	Supported
-- 
2.18.0