Gunyah is a Type-1 hypervisor independent of any high-level OS kernel,
and runs in a higher CPU privilege level. It does not depend on any
lower-privileged OS kernel/code for its core functionality. This
increases its security and can support a much smaller trusted computing
base than a Type-2 hypervisor. Gunyah is designed for isolated virtual
machine use cases and to support launching trusted+isolated virtual
machines from a relatively less trusted host virtual machine.
Gunyah is an open source hypervisor. The source repo is available at
https://github.com/quic/gunyah-hypervisor.
The diagram below shows the architecture for AArch64.
::
VM A VM B
+-----+ +-----+ | +-----+ +-----+ +-----+
| | | | | | | | | | |
EL0 | APP | | APP | | | APP | | APP | | APP |
| | | | | | | | | | |
+-----+ +-----+ | +-----+ +-----+ +-----+
---------------------|-------------------------
+--------------+ | +----------------------+
| | | | |
EL1 | Linux Kernel | | |Linux kernel/Other OS | ...
| | | | |
+--------------+ | +----------------------+
--------hvc/smc------|------hvc/smc------------
+----------------------------------------+
| |
EL2 | Gunyah Hypervisor |
| |
+----------------------------------------+
Gunyah provides these following features.
- Threads and Scheduling: The scheduler schedules virtual CPUs (VCPUs)
on physical CPUs and enables time-sharing of the CPUs.
- Memory Management: Gunyah tracks memory ownership and use of all
memory under its control. It provides low level dynamic memory
management APIs on top of which higher level donation, lending and sharing
is built. Gunyah provides strong VM memory isolation for trusted VMs.
- Interrupt Virtualization: Interrupts are managed by the hypervisor
and are routed directly to the assigned VM.
- Inter-VM Communication: There are several different mechanisms
provided for communicating between VMs.
- Device Virtualization: Para-virtualization of devices is supported
using inter-VM communication and virtio primitives. Low level architecture
features and devices such as cpu timers, interrupt controllers are supported
with hardware virtualization and emulation where required.
- Resource Manager: Gunyah supports a "root" VM that initially owns all
VM memory and IO resources. The Gunyah Resource Manager is the default
bundled root VM and provides high-level services including dynamic VM
management and secure memory donation, lending and sharing.
This series adds the basic framework for detecting that Linux is running
under Gunyah as a virtual machine, communication with the Gunyah
Resource Manager, and a sample virtual machine manager capable of
launching virtual machines.
Changes in v17:
- Replace RM's irq_chip with irq_create_fwspec_mapping
- Unmap lent memory from kernel logical map
- Small optimization to unlock folio earlier to allow vCPUs racing for
the same folio to run sooner
- Add missed "safe to lend" checks for a folio when constructing mem
parcel
Changes in v16:
https://lore.kernel.org/r/20240109-gunyah-v16-0-634904bf4ce9@quicinc.com
- Fleshed out memory reclaim while VM is running
- Documentation and comments
Changes in v15:
https://lore.kernel.org/r/20231215-gunyah-v15-0-192a5d872a30@quicinc.com
- First implementation of virtual machines backed by guestmemfd and
using demand paging to provide memory instead of all up front.
- Use message queue hypercalls directly instead of traversing through
mailbox framework.
Changes in v14: https://lore.kernel.org/all/20230613172054.3959700-1-quic_eberman@quicinc.com/
- Coding/cosmetic tweaks suggested by Alex
- Mark IRQs as wake-up capable
Changes in v13:
https://lore.kernel.org/all/20230509204801.2824351-1-quic_eberman@quicinc.com/
- Tweaks to message queue driver to address race condition between IRQ
and mailbox registration
- Allow removal of VM functions by function-specific comparison --
specifically to allow
removing irqfd by label only and not requiring original FD to be
provided.
Changes in v12:
https://lore.kernel.org/all/20230424231558.70911-1-quic_eberman@quicinc.com/
- Stylistic/cosmetic tweaks suggested by Alex
- Remove patch "virt: gunyah: Identify hypervisor version" and squash
the
check that we're running under a reasonable Gunyah hypervisor into RM
driver
- Refactor platform hooks into a separate module per suggestion from
Srini
- GFP_KERNEL_ACCOUNT and account_locked_vm() for page pinning
- enum-ify related constants
Changes in v11:
https://lore.kernel.org/all/20230304010632.2127470-1-quic_eberman@quicinc.com/
- Rename struct gh_vm_dtb_config:gpa -> guest_phys_addr & overflow
checks for this
- More docstrings throughout
- Make resp_buf and resp_buf_size optional
- Replace deprecated idr with xarray
- Refconting on misc device instead of RM's platform device
- Renaming variables, structs, etc. from gunyah_ -> gh_
- Drop removal of user mem regions
- Drop mem_lend functionality; to converge with restricted_memfd later
Changes in v10:
https://lore.kernel.org/all/20230214211229.3239350-1-quic_eberman@quicinc.com/
- Fix bisectability (end result of series is same, --fixups applied to
wrong commits)
- Convert GH_ERROR_* and GH_RM_ERROR_* to enums
- Correct race condition between allocating/freeing user memory
- Replace offsetof with struct_size
- Series-wide renaming of functions to be more consistent
- VM shutdown & restart support added in vCPU and VM Manager patches
- Convert VM function name (string) to type (number)
- Convert VM function argument to value (which could be a pointer) to
remove memory wastage for arguments
- Remove defensive checks of hypervisor correctness
- Clean ups to ioeventfd as suggested by Srivatsa
Changes in v9:
https://lore.kernel.org/all/20230120224627.4053418-1-quic_eberman@quicinc.com/
- Refactor Gunyah API flags to be exposed as feature flags at kernel
level
- Move mbox client cleanup into gunyah_msgq_remove()
- Simplify gh_rm_call return value and response payload
- Missing clean-up/error handling/little endian fixes as suggested by
Srivatsa and Alex in v8 series
Changes in v8:
https://lore.kernel.org/all/20221219225850.2397345-1-quic_eberman@quicinc.com/
- Treat VM manager as a library of RM
- Add patches 21-28 as RFC to support proxy-scheduled vCPUs and
necessary bits to support virtio
from Gunyah userspace
Changes in v7:
https://lore.kernel.org/all/20221121140009.2353512-1-quic_eberman@quicinc.com/
- Refactor to remove gunyah RM bus
- Refactor allow multiple RM device instances
- Bump UAPI to start at 0x0
- Refactor QCOM SCM's platform hooks to allow
CONFIG_QCOM_SCM=Y/CONFIG_GUNYAH=M combinations
Changes in v6:
https://lore.kernel.org/all/20221026185846.3983888-1-quic_eberman@quicinc.com/
- *Replace gunyah-console with gunyah VM Manager*
- Move include/asm-generic/gunyah.h into include/linux/gunyah.h
- s/gunyah_msgq/gh_msgq/
- Minor tweaks and documentation tidying based on comments from Jiri,
Greg, Arnd, Dmitry, and Bagas.
Changes in v5
https://lore.kernel.org/all/20221011000840.289033-1-quic_eberman@quicinc.com/
- Dropped sysfs nodes
- Switch from aux bus to Gunyah RM bus for the subdevices
- Cleaning up RM console
Changes in v4:
https://lore.kernel.org/all/20220928195633.2348848-1-quic_eberman@quicinc.com/
- Tidied up documentation throughout based on questions/feedback received
- Switched message queue implementation to use mailboxes
- Renamed "gunyah_device" as "gunyah_resource"
Changes in v3:
https://lore.kernel.org/all/20220811214107.1074343-1-quic_eberman@quicinc.com/
- /Maintained/Supported/ in MAINTAINERS
- Tidied up documentation throughout based on questions/feedback received
- Moved hypercalls into arch/arm64/gunyah/; following hyper-v's implementation
- Drop opaque typedefs
- Move sysfs nodes under /sys/hypervisor/gunyah/
- Moved Gunyah console driver to drivers/tty/
- Reworked gh_device design to drop the Gunyah bus.
Changes in v2: https://lore.kernel.org/all/20220801211240.597859-1-quic_eberman@quicinc.com/
- DT bindings clean up
- Switch hypercalls to follow SMCCC
v1: https://lore.kernel.org/all/20220223233729.1571114-1-quic_eberman@quicinc.com/
Signed-off-by: Elliot Berman <quic_eberman@quicinc.com>
---
Elliot Berman (35):
docs: gunyah: Introduce Gunyah Hypervisor
dt-bindings: Add binding for gunyah hypervisor
gunyah: Common types and error codes for Gunyah hypercalls
virt: gunyah: Add hypercalls to identify Gunyah
virt: gunyah: Add hypervisor driver
virt: gunyah: msgq: Add hypercalls to send and receive messages
gunyah: rsc_mgr: Add resource manager RPC core
gunyah: vm_mgr: Introduce basic VM Manager
gunyah: rsc_mgr: Add VM lifecycle RPC
gunyah: vm_mgr: Add VM start/stop
virt: gunyah: Translate gh_rm_hyp_resource into gunyah_resource
virt: gunyah: Add resource tickets
gunyah: vm_mgr: Add framework for VM Functions
virt: gunyah: Add hypercalls for running a vCPU
virt: gunyah: Add proxy-scheduled vCPUs
gunyah: Add hypercalls for demand paging
gunyah: rsc_mgr: Add memory parcel RPC
mm/interval_tree: Export iter_first/iter_next
arch/mm: Export direct {un,}map functions
virt: gunyah: Add interfaces to map memory into guest address space
gunyah: rsc_mgr: Add platform ops on mem_lend/mem_reclaim
virt: gunyah: Add Qualcomm Gunyah platform ops
virt: gunyah: Implement guestmemfd
virt: gunyah: Add ioctl to bind guestmem to VMs
virt: gunyah: guestmem: Initialize RM mem parcels from guestmem
virt: gunyah: Share guest VM dtb configuration to Gunyah
gunyah: rsc_mgr: Add RPC to enable demand paging
virt: gunyah: Enable demand paging
gunyah: rsc_mgr: Add RPC to set VM boot context
virt: gunyah: Allow userspace to initialize context of primary vCPU
virt: gunyah: Add hypercalls for sending doorbell
virt: gunyah: Add irqfd interface
virt: gunyah: Add IO handlers
virt: gunyah: Add ioeventfd
MAINTAINERS: Add Gunyah hypervisor drivers section
.../bindings/firmware/gunyah-hypervisor.yaml | 82 ++
Documentation/userspace-api/ioctl/ioctl-number.rst | 1 +
Documentation/virt/gunyah/index.rst | 135 +++
Documentation/virt/gunyah/message-queue.rst | 68 ++
Documentation/virt/index.rst | 1 +
MAINTAINERS | 12 +
arch/arm64/Kbuild | 1 +
arch/arm64/gunyah/Makefile | 3 +
arch/arm64/gunyah/gunyah_hypercall.c | 279 ++++++
arch/arm64/include/asm/gunyah.h | 57 ++
arch/arm64/mm/pageattr.c | 3 +
drivers/virt/Kconfig | 2 +
drivers/virt/Makefile | 1 +
drivers/virt/gunyah/Kconfig | 47 +
drivers/virt/gunyah/Makefile | 9 +
drivers/virt/gunyah/guest_memfd.c | 987 ++++++++++++++++++++
drivers/virt/gunyah/gunyah.c | 52 ++
drivers/virt/gunyah/gunyah_ioeventfd.c | 139 +++
drivers/virt/gunyah/gunyah_irqfd.c | 187 ++++
drivers/virt/gunyah/gunyah_platform_hooks.c | 117 +++
drivers/virt/gunyah/gunyah_qcom.c | 220 +++++
drivers/virt/gunyah/gunyah_vcpu.c | 590 ++++++++++++
drivers/virt/gunyah/rsc_mgr.c | 836 +++++++++++++++++
drivers/virt/gunyah/rsc_mgr.h | 144 +++
drivers/virt/gunyah/rsc_mgr_rpc.c | 602 +++++++++++++
drivers/virt/gunyah/vm_mgr.c | 993 +++++++++++++++++++++
drivers/virt/gunyah/vm_mgr.h | 215 +++++
drivers/virt/gunyah/vm_mgr_mem.c | 356 ++++++++
include/linux/gunyah.h | 483 ++++++++++
include/uapi/linux/gunyah.h | 378 ++++++++
mm/interval_tree.c | 3 +
31 files changed, 7003 insertions(+)
---
base-commit: ffd2cb6b718e189e7e2d5d0c19c25611f92e061a
change-id: 20231208-gunyah-952aca7668e0
Best regards,
--
Elliot Berman <quic_eberman@quicinc.com>