mirror of
https://github.com/xen-project/xen.git
synced 2026-10-28 02:01:24 +01:00
Jan Beulich
9c94eda1e3
When multiple devices share resources and one of them is to be passed through to a guest, security of the entire system and of respective guests individually cannot really be guaranteed without knowing internals of any of the involved guests. Therefore such a configuration cannot really be security-supported, yet making that explicit was so far missing. This is XSA-461 / CVE-2024-31146. Signed-off-by: Jan Beulich <jbeulich@suse.com> Reviewed-by: Juergen Gross <jgross@suse.com>
1210 lines
31 KiB
Markdown
1210 lines
31 KiB
Markdown
% Support statement for this release
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This document describes the support status
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and in particular the security support status of the Xen branch
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within which you find it.
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See the bottom of the file
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for the definitions of the support status levels etc.
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# Release Support
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Xen-Version: 4.20-unstable
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Initial-Release: n/a
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Supported-Until: TBD
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Security-Support-Until: Unreleased - not yet security-supported
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Release Notes
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: <a href="https://wiki.xenproject.org/wiki/Xen_Project_X.YY_Release_Notes">RN</a>
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# Feature Support
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## Kconfig
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EXPERT and DEBUG Kconfig options are not security supported. Other
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Kconfig options are supported, if the related features are marked as
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supported in this document.
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## Host Architecture
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### x86-64
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Status: Supported
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Status, Xeon Phi: Not supported.
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### ARM v7 + Virtualization Extensions
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Status: Supported
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### ARM v8
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Status, Xen in AArch64 mode: Supported
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Status, Xen in AArch32 mode: Tech Preview
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Status, Cortex A57 r0p0-r1p1: Supported, not security supported
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Status, Cortex A77 r0p0-r1p0: Supported, not security supported
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For the Cortex A57 r0p0 - r1p1, see Errata 832075.
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For the Cortex A77 r0p0 - r1p0, see Errata 1508412.
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## Host hardware support
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### ACPI CPU Hotplug
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Status, x86: Experimental
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### Physical Memory
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Status, x86: Supported up to 12 TiB. Hosts with more memory are supported, but not security supported.
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Status, Arm32: Supported up to 12 GiB
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Status, Arm64: Supported up to 2 TiB
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### Physical Memory Hotplug
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Status, x86: Supported
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### Physical CPUs
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Status, x86: Supported up to 4096
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Status, ARM: Supported up to 128
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### Host ACPI (via Domain 0)
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Status, x86 PV: Supported
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Status, ARM: Experimental
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### Host EFI Boot
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Status, x86: Supported
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Status, Arm64: Supported
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### Host EFI Secure Boot
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Status, x86: Experimental
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Status, Arm64: Experimental
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### x86/Intel Platform QoS Technologies
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Status: Tech Preview
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### IOMMU
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Status, AMD IOMMU: Supported
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Status, Intel VT-d: Supported
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Status, ARM SMMUv1: Supported, not security supported
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Status, ARM SMMUv2: Supported, not security supported
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Status, ARM SMMUv3: Tech Preview
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Status, Renesas IPMMU-VMSA: Supported, not security supported
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### ARM/GICv3
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GICv3 is an interrupt controller specification designed by Arm.
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Status, Arm64: Security supported
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Status, Arm32: Supported, not security supported
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### ARM/GICv3 ITS
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Extension to the GICv3 interrupt controller to support MSI.
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Status: Experimental
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### ARM/Partial Emulation
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Enable partial emulation of registers, otherwise considered unimplemented,
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that would normally trigger a fault injection.
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Status: Supported, with caveats
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Only the following system registers are security supported:
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* MDCCSR_EL0
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* DBGDTR_EL0
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* DBGDTRTX_EL0
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* DBGDTRRX_EL0
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* DBGDSCRINT
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* DBGDTRTXINT
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* DBGDTRRXINT
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### ARM Scalable Vector Extension (SVE/SVE2)
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Arm64 domains can use Scalable Vector Extension (SVE/SVE2).
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Status: Tech Preview
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## Guest Type
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### x86/PV
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Traditional Xen PV guest
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No hardware requirements
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Status, x86_64: Supported
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Status, x86_32, shim: Supported
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Status, x86_32, without shim: Supported, not security supported
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### x86/HVM
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Fully virtualised guest using hardware virtualisation extensions
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Requires hardware virtualisation support (Intel VMX / AMD SVM)
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Status, domU: Supported
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### x86/PVH
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PVH is a next-generation paravirtualized mode
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designed to take advantage of hardware virtualization support when possible.
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During development this was sometimes called HVMLite or PVHv2.
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Requires hardware virtualisation support (Intel VMX / AMD SVM).
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Dom0 support requires an IOMMU (Intel VT-d / AMD IOMMU).
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Status, domU: Supported
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Status, dom0: Supported, with caveats
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PVH dom0 hasn't received the same test coverage as PV dom0, so it can exhibit
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unexpected behavior or issues on some hardware.
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At least the following features are missing on a PVH dom0:
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* PCI SR-IOV and Resizable BARs.
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* Native NMI forwarding (nmi=dom0 command line option).
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* MCE handling.
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* PCI Passthrough to any kind of domUs.
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### ARM
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ARM only has one guest type at the moment
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Status: Supported
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## Guest Limits
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### Memory
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Status, x86: Supported up to 8 TiB. Guests with more memory, but less than 16 TiB, are supported, but not security supported.
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Status, Arm32: Supported up to 12 GiB
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Status, Arm64: Supported up to 1 TiB
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## Hypervisor file system
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### Build info
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Status: Supported
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### Hypervisor config
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Status: Supported
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### Runtime parameters
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Status: Supported
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## Toolstack
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While 32-bit builds of the tool stack are generally supported, restrictions
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apply in particular when running on top of a 64-bit hypervisor. For example,
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very large guests aren't expected to be manageable in this case. This includes
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guests giving the appearance of being large, by altering their own memory
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layouts.
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### xl
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Status: Supported
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### Direct-boot kernel image format
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Format which the toolstack accepts for direct-boot kernels
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Supported, x86: bzImage, ELF
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Supported, ARM32: zImage
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Supported, ARM64: Image
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### Dom0 init support for xl
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Status, SysV: Supported
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Status, systemd: Supported
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Status, BSD-style: Supported
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### JSON output support for xl
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Output of information in machine-parseable JSON format
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Status: Experimental
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### Open vSwitch integration for xl
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Status, Linux: Supported
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### Virtual cpu hotplug
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Status: Supported
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### QEMU backend hotplugging for xl
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Status: Supported
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### xenlight Go package
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Go (golang) bindings for libxl
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Status: Experimental
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### Linux device model stubdomains
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Support for running qemu-xen device model in a linux stubdomain.
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Status: Tech Preview
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## Xenstore
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### C xenstored daemon
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Status: Supported
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Status, Liveupdate: Tech Preview
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### OCaml xenstored daemon
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Status: Supported
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Status, untrusted driver domains: Supported, not security supported
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Status, Liveupdate: Not functional
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## Toolstack/3rd party
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### libvirt driver for xl
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Status: Supported, Security support external
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## Debugging, analysis, and crash post-mortem
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### Host serial console
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Status, NS16550: Supported
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Status, EHCI: Supported
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Status, Cadence UART (ARM): Supported
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Status, PL011 UART (ARM): Supported
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Status, Exynos 4210 UART (ARM): Supported
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Status, OMAP UART (ARM): Supported
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Status, SCI(F) UART: Supported
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### Hypervisor 'debug keys'
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These are functions triggered either from the host serial console,
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or via the xl 'debug-keys' command,
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which cause Xen to dump various hypervisor state to the console.
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Status: Supported, not security supported
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### Hypervisor synchronous console output (sync_console)
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Xen command-line flag to force synchronous console output.
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Status: Supported, not security supported
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Useful for debugging, but not suitable for production environments
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due to incurred overhead.
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### gdbsx
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Status, x86: Supported, not security supported
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Debugger to debug ELF guests
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### Soft-reset for PV guests
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Soft-reset allows a new kernel to start 'from scratch' with a fresh VM state,
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but with all the memory from the previous state of the VM intact.
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This is primarily designed to allow "crash kernels",
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which can do core dumps of memory to help with debugging in the event of a crash.
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Status: Supported
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### xentrace
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Tool to capture Xen trace buffer data
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Status, x86: Supported
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### gcov
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Export hypervisor coverage data suitable for analysis by gcov or lcov.
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Status: Supported, Not security supported
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### Processor trace support
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Support for using Intel Processor Trace technology to trace guests
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from dom0.
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Status, x86: Tech Preview
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## Memory Management
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### Dynamic memory control
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Allows a guest to add or remove memory after boot-time.
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This is typically done by a guest kernel agent known as a "balloon driver".
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Status: Supported
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### Populate-on-demand memory
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This is a mechanism that allows normal operating systems with only a balloon driver
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to boot with memory < maxmem.
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Status, x86 HVM: Supported
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### Static Allocation
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Static allocation refers to domains for which memory areas are
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pre-defined by configuration using physical address ranges.
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Status, ARM: Tech Preview
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### Static Heap
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Allow reserving parts of RAM through the device tree using physical
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address ranges as heap.
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Status, ARM: Tech Preview
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### Memory Sharing
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Allow sharing of identical pages between guests
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Status, x86 HVM: Experimental
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### Static Memory Sharing
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Allow to statically set up shared memory on dom0less system,
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enabling domains to do shm-based communication
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Status, ARM: Tech Preview
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### Memory Paging
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Allow pages belonging to guests to be paged to disk
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Status, x86 HVM: Experimental
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### Alternative p2m
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Alternative p2m (altp2m) allows external monitoring of guest memory
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by maintaining multiple physical to machine (p2m) memory mappings.
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Status, x86 HVM: Tech Preview
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Status, ARM: Tech Preview
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## Resource Management
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### CPU Pools
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Groups physical cpus into distinct groups called "cpupools",
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with each pool having the capability
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of using different schedulers and scheduling properties.
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Status: Supported
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### Core Scheduling
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Allows to group virtual cpus into virtual cores which are scheduled on the
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physical cores. This results in never running different guests at the same
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time on the same physical core.
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Status, x86: Experimental
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### Credit Scheduler
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A weighted proportional fair share virtual CPU scheduler.
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This is the default scheduler.
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Status: Supported
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### Credit2 Scheduler
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A general purpose scheduler for Xen,
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designed with particular focus on fairness, responsiveness, and scalability
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Status: Supported
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### RTDS based Scheduler
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A soft real-time CPU scheduler
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built to provide guaranteed CPU capacity to guest VMs on SMP hosts
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Status: Experimental
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### ARINC653 Scheduler
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A periodically repeating fixed timeslice scheduler.
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Status: Supported
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Currently only single-vcpu domains are supported.
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### Null Scheduler
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A very simple, very static scheduling policy
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that always schedules the same vCPU(s) on the same pCPU(s).
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It is designed for maximum determinism and minimum overhead
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on embedded platforms and the x86 PV shim.
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Status: Experimental
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Status, x86/shim: Supported
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### NUMA scheduler affinity
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Enables NUMA aware scheduling in Xen
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Status, x86: Supported
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## Scalability
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### Super page support
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NB that this refers to the ability of guests
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to have higher-level page table entries point directly to memory,
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improving TLB performance.
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On ARM, and on x86 in HAP mode,
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the guest has whatever support is enabled by the hardware.
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This feature is independent
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of the ARM "page granularity" feature (see below).
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Status, x86 HVM/PVH, HAP: Supported
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Status, x86 HVM/PVH, Shadow, 2MiB: Supported
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Status, ARM: Supported
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On x86 in shadow mode, only 2MiB (L2) superpages are available;
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furthermore, they do not have the performance characteristics
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of hardware superpages.
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### x86/PVHVM
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This is a useful label for a set of hypervisor features
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which add paravirtualized functionality to HVM guests
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for improved performance and scalability.
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This includes exposing event channels to HVM guests.
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Status: Supported
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## High Availability and Fault Tolerance
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### Remus Fault Tolerance
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Status: Experimental
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### COLO Manager
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Status: Experimental
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### x86/vMCE
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Forward Machine Check Exceptions to appropriate guests
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Status: Supported
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## Virtual driver support, guest side
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### Blkfront
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Guest-side driver capable of speaking the Xen PV block protocol
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Status, Linux: Supported
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Status, FreeBSD: Supported, Security support external
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Status, NetBSD: Supported, Security support external
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Status, OpenBSD: Supported, Security support external
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Status, Windows: Supported, with caveats
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Windows frontend currently trusts the backend;
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bugs in the frontend which allow backend to cause mischief will not be
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considered security vulnerabilities.
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### Netfront
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Guest-side driver capable of speaking the Xen PV networking protocol
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Status, Linux: Supported
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Status, FreeBSD: Supported, Security support external
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Status, NetBSD: Supported, Security support external
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Status, OpenBSD: Supported, Security support external
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Status, Windows: Supported, with caveats
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Windows frontend currently trusts the backend;
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bugs in the frontend which allow backend to cause mischief will not be
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considered security vulnerabilities.
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### PV Framebuffer (frontend)
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Guest-side driver capable of speaking the Xen PV Framebuffer protocol
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Status, Linux (xen-fbfront): Supported, with caveats
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Linux frontend currently trusts the backend;
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bugs in the frontend which allow backend to cause mischief will not be
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considered security vulnerabilities.
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### PV display (frontend)
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Guest-side driver capable of speaking the Xen PV display protocol
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Status, Linux, outside of "backend allocation" mode: Supported, with caveats
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Status, Linux, "backend allocation" mode: Experimental
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Linux frontend currently trusts the backend;
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bugs in the frontend which allow backend to cause mischief will not be
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considered security vulnerabilities.
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### PV Console (frontend)
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Guest-side driver capable of speaking the Xen PV console protocol
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Status, Linux (hvc_xen): Supported
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Status, FreeBSD: Supported, Security support external
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Status, NetBSD: Supported, Security support external
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Status, Windows: Supported, with caveats
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Windows frontend currently trusts the backend;
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bugs in the frontend which allow backend to cause mischief will not be
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considered security vulnerabilities.
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### PV keyboard (frontend)
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Guest-side driver capable of speaking the Xen PV keyboard protocol.
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Note that the "keyboard protocol" includes mouse / pointer /
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multi-touch support as well.
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Status, Linux (xen-kbdfront): Supported, with caveats
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Linux frontend currently trusts the backend;
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bugs in the frontend which allow backend to cause mischief will not be
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considered security vulnerabilities.
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### PV USB (frontend)
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Status, Linux: Supported, with caveats
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Linux frontend currently trusts the backend;
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bugs in the frontend which allow backend to cause mischief will not be
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considered security vulnerabilities.
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### PV SCSI protocol (frontend)
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Status, Linux: Supported, with caveats
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NB that while the PV SCSI frontend is in Linux and tested regularly,
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there is currently no xl support.
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Linux frontend currently trusts the backend;
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bugs in the frontend which allow backend to cause mischief will not be
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considered security vulnerabilities.
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### PV TPM (frontend)
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Guest-side driver capable of speaking the Xen PV TPM protocol
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Status, Linux (xen-tpmfront): Tech Preview
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### PV 9pfs frontend
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Guest-side driver capable of speaking the Xen 9pfs protocol
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Status, Linux: Tech Preview
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### PVCalls (frontend)
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Guest-side driver capable of making pv system calls
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Status, Linux: Tech Preview
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### PV sound (frontend)
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Guest-side driver capable of speaking the Xen PV sound protocol
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Status, Linux: Supported, with caveats
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Linux frontend currently trusts the backend;
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bugs in the frontend which allow backend to cause mischief will not be
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considered security vulnerabilities.
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## Virtual device support, host side
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|
|
For host-side virtual device support,
|
|
"Supported" and "Tech preview" include xl/libxl support
|
|
unless otherwise noted.
|
|
|
|
### Blkback
|
|
|
|
Host-side implementations of the Xen PV block protocol.
|
|
|
|
Status, Linux (xen-blkback): Supported
|
|
Status, QEMU (xen_disk), raw format: Supported
|
|
Status, QEMU (xen_disk), qcow format: Supported
|
|
Status, QEMU (xen_disk), qcow2 format: Supported
|
|
Status, QEMU (xen_disk), vhd format: Supported
|
|
Status, FreeBSD (blkback): Supported, Security support external
|
|
Status, NetBSD (xbdback): Supported, security support external
|
|
Status, Blktap2, raw format: Deprecated
|
|
Status, Blktap2, vhd format: Deprecated
|
|
|
|
Backends only support raw format unless otherwise specified.
|
|
|
|
### Netback
|
|
|
|
Host-side implementations of Xen PV network protocol
|
|
|
|
Status, Linux (xen-netback): Supported
|
|
Status, FreeBSD (netback): Supported, Security support external
|
|
Status, NetBSD (xennetback): Supported, Security support external
|
|
|
|
### PV Framebuffer (backend)
|
|
|
|
Host-side implementation of the Xen PV framebuffer protocol
|
|
|
|
Status, QEMU: Supported
|
|
|
|
### PV Console (xenconsoled)
|
|
|
|
Host-side implementation of the Xen PV console protocol
|
|
|
|
Status: Supported
|
|
|
|
### PV keyboard (backend)
|
|
|
|
Host-side implementation of the Xen PV keyboard protocol.
|
|
Note that the "keyboard protocol" includes mouse / pointer support as well.
|
|
|
|
Status, QEMU: Supported
|
|
|
|
### PV USB (backend)
|
|
|
|
Host-side implementation of the Xen PV USB protocol
|
|
|
|
Status, QEMU: Supported
|
|
|
|
### PV SCSI protocol (backend)
|
|
|
|
Status, Linux: Experimental
|
|
|
|
NB that while the PV SCSI backend is in Linux and tested regularly,
|
|
there is currently no xl support.
|
|
|
|
### PV TPM (backend)
|
|
|
|
Status: Tech Preview
|
|
|
|
### PV 9pfs (backend)
|
|
|
|
Status, QEMU: Tech Preview
|
|
Status, xen-9pfsd: Experimental
|
|
|
|
### PVCalls (backend)
|
|
|
|
Status, Linux: Experimental
|
|
|
|
PVCalls backend has been checked into Linux,
|
|
but has no xl support.
|
|
|
|
### Online resize of virtual disks
|
|
|
|
Status: Supported
|
|
|
|
## Security
|
|
|
|
### Driver Domains
|
|
|
|
"Driver domains" means allowing non-Domain 0 domains
|
|
with access to physical devices to act as back-ends.
|
|
|
|
Status: Supported, with caveats
|
|
|
|
See the appropriate "Device Passthrough" section
|
|
for more information about security support.
|
|
|
|
### Device Model Stub Domains
|
|
|
|
Status: Supported, with caveats
|
|
|
|
Vulnerabilities of a device model stub domain
|
|
to a hostile driver domain (either compromised or untrusted)
|
|
are excluded from security support.
|
|
|
|
### Device Model Deprivileging
|
|
|
|
Status, Linux dom0: Tech Preview, with limited support
|
|
|
|
This means adding extra restrictions to a device model in order to
|
|
prevent a compromised device model from attacking the rest of the
|
|
domain it's running in (normally dom0).
|
|
|
|
"Tech preview with limited support" means we will not issue XSAs for
|
|
the _additional_ functionality provided by the feature; but we will
|
|
issue XSAs in the event that enabling this feature opens up a security
|
|
hole that would not be present without the feature disabled.
|
|
|
|
For example, while this is classified as tech preview, a bug in libxl
|
|
which failed to change the user ID of QEMU would not receive an XSA,
|
|
since without this feature the user ID wouldn't be changed. But a
|
|
change which made it possible for a compromised guest to read
|
|
arbitrary files on the host filesystem without compromising QEMU would
|
|
be issued an XSA, since that does weaken security.
|
|
|
|
### KCONFIG Expert
|
|
|
|
Status: Experimental
|
|
|
|
### Live Patching
|
|
|
|
Status, x86: Supported
|
|
Status, ARM: Experimental
|
|
|
|
Compile time disabled for ARM by default.
|
|
|
|
### Virtual Machine Introspection
|
|
|
|
Status, x86: Supported, not security supported
|
|
|
|
### XSM & FLASK
|
|
|
|
Status: Experimental
|
|
|
|
Compile time disabled by default.
|
|
|
|
Also note that using XSM
|
|
to delegate various domain control hypercalls
|
|
to particular other domains, rather than only permitting use by dom0,
|
|
is also specifically excluded from security support for many hypercalls.
|
|
Please see XSA-77 for more details.
|
|
|
|
### FLASK default policy
|
|
|
|
Status: Experimental
|
|
|
|
The default policy includes FLASK labels and roles for a "typical" Xen-based system
|
|
with dom0, driver domains, stub domains, domUs, and so on.
|
|
|
|
## Virtual Hardware, Hypervisor
|
|
|
|
### x86/Nested PV
|
|
|
|
This means running a Xen hypervisor inside an HVM domain on a Xen system,
|
|
with support for PV L2 guests only
|
|
(i.e., hardware virtualization extensions not provided
|
|
to the guest).
|
|
|
|
Status, x86 Xen HVM: Tech Preview
|
|
|
|
This works, but has performance limitations
|
|
because the L1 dom0 can only access emulated L1 devices.
|
|
|
|
Xen may also run inside other hypervisors (KVM, Hyper-V, VMWare),
|
|
but nobody has reported on performance.
|
|
|
|
### x86/Nested HVM
|
|
|
|
This means providing hardware virtulization support to guest VMs
|
|
allowing, for instance, a nested Xen to support both PV and HVM guests.
|
|
It also implies support for other hypervisors,
|
|
such as KVM, Hyper-V, Bromium, and so on as guests.
|
|
|
|
Status, x86 HVM: Experimental
|
|
|
|
### vPMU
|
|
|
|
Virtual Performance Management Unit
|
|
|
|
Status, x86 HVM: Supported, Not security supported
|
|
Status, ARM: Experimental
|
|
|
|
On ARM, support for accessing PMU registers from the guests.
|
|
There is no interrupt support and Xen will not save/restore
|
|
the register values on context switches.
|
|
|
|
Disabled by default.
|
|
On ARM, enable with guest parameter.
|
|
On x86, enable with hypervisor command line option.
|
|
|
|
This feature is not security supported: see https://xenbits.xen.org/xsa/advisory-163.html
|
|
|
|
### Argo: Inter-domain message delivery by hypercall
|
|
|
|
Status: Experimental
|
|
|
|
### x86/PCI Device Passthrough
|
|
|
|
Status, x86 PV: Supported, with caveats
|
|
Status, x86 HVM: Supported, with caveats
|
|
|
|
Only systems using IOMMUs are supported.
|
|
|
|
Passing through of devices sharing resources with another device is not
|
|
security supported. Such sharing could e.g. be the same line interrupt being
|
|
used by multiple devices, one of which is to be passed through, or two such
|
|
devices having memory BARs within the same 4k page.
|
|
|
|
Not compatible with migration, populate-on-demand, altp2m,
|
|
introspection, memory sharing, or memory paging.
|
|
|
|
Because of hardware limitations
|
|
(affecting any operating system or hypervisor),
|
|
it is generally not safe to use this feature
|
|
to expose a physical device to completely untrusted guests.
|
|
However, this feature can still confer significant security benefit
|
|
when used to remove drivers and backends from domain 0
|
|
(i.e., Driver Domains).
|
|
|
|
### x86/Multiple IOREQ servers
|
|
|
|
An IOREQ server provides emulated devices to HVM and PVH guests.
|
|
QEMU is normally the only IOREQ server,
|
|
but Xen has support for multiple IOREQ servers.
|
|
This allows for custom or proprietary device emulators
|
|
to be used in addition to QEMU.
|
|
|
|
Status: Experimental
|
|
|
|
### ARM/IOREQ servers
|
|
|
|
Status: Tech Preview
|
|
|
|
### ARM/Non-PCI device passthrough
|
|
|
|
Status: Supported, not security supported
|
|
|
|
Note that this still requires an IOMMU
|
|
that covers the DMA of the device to be passed through.
|
|
|
|
### ARM: 16K and 64K page granularity in guests
|
|
|
|
Status: Supported, with caveats
|
|
|
|
No support for QEMU backends in a 16K or 64K domain.
|
|
|
|
### ARM: Firmware Framework for Arm A-profile (FF-A) Mediator
|
|
|
|
Status, Arm64: Tech Preview
|
|
|
|
There are still some code paths where a vCPU may hog a pCPU longer than
|
|
necessary. The FF-A mediator is not yet implemented for Arm32. Part of the
|
|
FF-A specification is not supported, see the top comment in
|
|
xen/arch/arm/tee/ffa.c for limitations.
|
|
|
|
### ARM: Guest Device Tree support
|
|
|
|
Status: Supported
|
|
|
|
### Device Tree Overlays
|
|
|
|
Add/Remove device tree nodes using a device tree overlay binary (.dtbo).
|
|
|
|
Status, ARM: Experimental
|
|
|
|
### ARM: Guest ACPI support
|
|
|
|
Status: Supported
|
|
|
|
### Arm: OP-TEE Mediator
|
|
|
|
Status: Tech Preview
|
|
|
|
## Virtual Hardware, QEMU
|
|
|
|
This section describes supported devices available in HVM mode using a
|
|
qemu devicemodel (the default).
|
|
|
|
Status: Support scope restricted
|
|
|
|
Note that other devices are available but not security supported.
|
|
|
|
### x86/Emulated platform devices (QEMU):
|
|
|
|
Status, piix3: Supported
|
|
|
|
### x86/Emulated network (QEMU):
|
|
|
|
Status, e1000: Supported
|
|
Status, rtl8193: Supported
|
|
Status, virtio-net: Supported
|
|
|
|
### x86/Emulated storage (QEMU):
|
|
|
|
Status, piix3 ide: Supported
|
|
Status, ahci: Supported
|
|
|
|
See the section **Blkback** for image formats supported by QEMU.
|
|
|
|
### x86/Emulated graphics (QEMU):
|
|
|
|
Status, cirrus-vga: Supported
|
|
Status, stdvga: Supported
|
|
|
|
### x86/Emulated audio (QEMU):
|
|
|
|
Status, sb16: Supported
|
|
Status, es1370: Supported
|
|
Status, ac97: Supported
|
|
|
|
### x86/Emulated input (QEMU):
|
|
|
|
Status, usbmouse: Supported
|
|
Status, usbtablet: Supported
|
|
Status, ps/2 keyboard: Supported
|
|
Status, ps/2 mouse: Supported
|
|
|
|
### x86/Emulated serial card (QEMU):
|
|
|
|
Status, UART 16550A: Supported
|
|
|
|
### x86/Host USB passthrough (QEMU):
|
|
|
|
Status: Supported, not security supported
|
|
|
|
### qemu-xen-traditional ###
|
|
|
|
The Xen Project provides an old version of qemu with modifications
|
|
which enable use as a device model stub domain. The old version is
|
|
normally selected by default only in a stub dm configuration, but it
|
|
can be requested explicitly in other configurations, for example in
|
|
`xl` with `device_model_version="QEMU_XEN_TRADITIONAL"`.
|
|
|
|
Status, Device Model Stub Domains: Supported, with caveats
|
|
Status, as host process device model: No security support, not recommended
|
|
|
|
qemu-xen-traditional is security supported only for those available
|
|
devices which are supported for mainstream QEMU (see above), with
|
|
trusted driver domains (see Device Model Stub Domains).
|
|
|
|
## Virtual Firmware
|
|
|
|
### x86/HVM iPXE
|
|
|
|
Booting a guest via PXE.
|
|
|
|
Status: Supported, with caveats
|
|
|
|
PXE inherently places full trust of the guest in the network,
|
|
and so should only be used
|
|
when the guest network is under the same administrative control
|
|
as the guest itself.
|
|
|
|
### x86/HVM BIOS
|
|
|
|
Booting a guest via guest BIOS firmware
|
|
|
|
Status, SeaBIOS (qemu-xen): Supported
|
|
Status, ROMBIOS (qemu-xen-traditional): Supported
|
|
|
|
### x86/HVM OVMF
|
|
|
|
OVMF firmware implements the UEFI boot protocol.
|
|
|
|
Status, qemu-xen: Supported
|
|
|
|
## Dom0less
|
|
|
|
Guest creation from the hypervisor at boot without Dom0 intervention.
|
|
|
|
Status, ARM: Supported
|
|
|
|
Memory of dom0less DomUs is not scrubbed at boot when bootscrub=on or
|
|
bootscrub=off are passed as Xen command line parameters. (Memory should
|
|
be scrubbed with bootscrub=idle.) No XSAs will be issues due to
|
|
unscrubbed memory.
|
|
|
|
## Static Event Channel
|
|
|
|
Allow to setup the static event channel on dom0less system, enabling domains
|
|
to send/receive notifications.
|
|
|
|
Status, ARM: Tech Preview
|
|
|
|
# Format and definitions
|
|
|
|
This file contains prose, and machine-readable fragments.
|
|
The data in a machine-readable fragment relate to
|
|
the section and subsection in which it is found.
|
|
|
|
The file is in markdown format.
|
|
The machine-readable fragments are markdown literals
|
|
containing RFC-822-like (deb822-like) data.
|
|
|
|
In each case, descriptions which expand on the name of a feature as
|
|
provided in the section heading, precede the Status indications.
|
|
Any paragraphs which follow the Status indication are caveats or
|
|
qualifications of the information provided in Status fields.
|
|
|
|
## Keys found in the Feature Support subsections
|
|
|
|
### Status
|
|
|
|
This gives the overall status of the feature,
|
|
including security support status, functional completeness, etc.
|
|
Refer to the detailed definitions below.
|
|
|
|
If support differs based on implementation
|
|
(for instance, x86 / ARM, Linux / QEMU / FreeBSD),
|
|
one line for each set of implementations will be listed.
|
|
|
|
## Definition of Status labels
|
|
|
|
Each Status value corresponds to levels of security support,
|
|
testing, stability, etc., as follows:
|
|
|
|
### Experimental
|
|
|
|
Functional completeness: No
|
|
Functional stability: Here be dragons
|
|
Interface stability: Not stable
|
|
Security supported: No
|
|
|
|
### Tech Preview
|
|
|
|
Functional completeness: Yes
|
|
Functional stability: Quirky
|
|
Interface stability: Provisionally stable
|
|
Security supported: No
|
|
|
|
#### Supported
|
|
|
|
Functional completeness: Yes
|
|
Functional stability: Normal
|
|
Interface stability: Yes
|
|
Security supported: Yes
|
|
|
|
#### Deprecated
|
|
|
|
Functional completeness: Yes
|
|
Functional stability: Quirky
|
|
Interface stability: No (as in, may disappear the next release)
|
|
Security supported: Yes
|
|
|
|
All of these may appear in modified form.
|
|
There are several interfaces, for instance,
|
|
which are officially declared as not stable;
|
|
in such a case this feature may be described as "Stable / Interface not stable".
|
|
|
|
## Definition of the status label interpretation tags
|
|
|
|
### Functionally complete
|
|
|
|
Does it behave like a fully functional feature?
|
|
Does it work on all expected platforms,
|
|
or does it only work for a very specific sub-case?
|
|
Does it have a sensible UI,
|
|
or do you have to have a deep understanding of the internals
|
|
to get it to work properly?
|
|
|
|
### Functional stability
|
|
|
|
What is the risk of it exhibiting bugs?
|
|
|
|
General answers to the above:
|
|
|
|
* **Here be dragons**
|
|
|
|
Pretty likely to still crash / fail to work.
|
|
Not recommended unless you like life on the bleeding edge.
|
|
|
|
* **Quirky**
|
|
|
|
Mostly works but may have odd behavior here and there.
|
|
Recommended for playing around or for non-production use cases.
|
|
|
|
* **Normal**
|
|
|
|
Ready for production use
|
|
|
|
### Interface stability
|
|
|
|
If I build a system based on the current interfaces,
|
|
will they still work when I upgrade to the next version?
|
|
|
|
* **Not stable**
|
|
|
|
Interface is still in the early stages and
|
|
still fairly likely to be broken in future updates.
|
|
|
|
* **Provisionally stable**
|
|
|
|
We're not yet promising backwards compatibility,
|
|
but we think this is probably the final form of the interface.
|
|
It may still require some tweaks.
|
|
|
|
* **Stable**
|
|
|
|
We will try very hard to avoid breaking backwards compatibility,
|
|
and to fix any regressions that are reported.
|
|
|
|
### Security supported
|
|
|
|
Will XSAs be issued if security-related bugs are discovered
|
|
in the functionality?
|
|
|
|
If "no",
|
|
anyone who finds a security-related bug in the feature
|
|
will be advised to
|
|
post it publicly to the Xen Project mailing lists
|
|
(or contact another security response team,
|
|
if a relevant one exists).
|
|
|
|
Bugs found after the end of **Security-Support-Until**
|
|
in the Release Support section will receive an XSA
|
|
if they also affect newer, security-supported, versions of Xen.
|
|
However, the Xen Project will not provide official fixes
|
|
for non-security-supported versions.
|
|
|
|
Three common 'diversions' from the 'Supported' category
|
|
are given the following labels:
|
|
|
|
* **Supported, Not security supported**
|
|
|
|
Functionally complete, normal stability,
|
|
interface stable, but no security support
|
|
|
|
* **Supported, Security support external**
|
|
|
|
This feature is security supported
|
|
by a different organization (not the XenProject).
|
|
The extent of support is defined by that organization.
|
|
It might be limited, e.g. like described in **Supported, with caveats**
|
|
below.
|
|
See **External security support** below.
|
|
|
|
* **Supported, with caveats**
|
|
|
|
This feature is security supported only under certain conditions,
|
|
or support is given only for certain aspects of the feature,
|
|
or the feature should be used with care
|
|
because it is easy to use insecurely without knowing it.
|
|
Additional details will be given in the description.
|
|
|
|
### Interaction with other features
|
|
|
|
Not all features interact well with all other features.
|
|
Some features are only for HVM guests; some don't work with migration, &c.
|
|
|
|
### External security support
|
|
|
|
The XenProject security team
|
|
provides security support for XenProject projects.
|
|
|
|
We also provide security support for Xen-related code in Linux,
|
|
which is an external project but doesn't have its own security process.
|
|
|
|
External projects that provide their own security support for Xen-related features are listed below.
|
|
|
|
* QEMU https://wiki.qemu.org/index.php/SecurityProcess
|
|
|
|
* Libvirt https://libvirt.org/securityprocess.html
|
|
|
|
* FreeBSD https://www.freebsd.org/security/
|
|
|
|
* NetBSD http://www.netbsd.org/support/security/
|
|
|
|
* OpenBSD https://www.openbsd.org/security.html
|