Xen ARM with Virtualization Extensions: Difference between revisions
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:A [[device tree]] in the flat device tree format (.dtb). The device tree source for the AEM is here: [http://xenbits.xen.org/gitweb/?p=people/dvrabel/device-trees.git;a=summary git://xenbits.xen.org/people/dvrabel/device-trees.git]. |
:A [[device tree]] in the flat device tree format (.dtb). The device tree source for the AEM is here: [http://xenbits.xen.org/gitweb/?p=people/dvrabel/device-trees.git;a=summary git://xenbits.xen.org/people/dvrabel/device-trees.git]. |
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;Xen |
;Xen |
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:xen-unstable as of |
:xen-unstable as of 1 Mar 2012. |
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;Linux kernel for dom0 |
;Linux kernel for dom0 |
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:vexpress-dt branch of [http://xenbits.xen.org/gitweb/?p=people/dvrabel/linux.git;a=summary git://xenbits.xen.org/people/dvrabel/linux.git] |
:vexpress-dt branch of [http://xenbits.xen.org/gitweb/?p=people/dvrabel/linux.git;a=summary git://xenbits.xen.org/people/dvrabel/linux.git] |
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The DTB to use is specified by the CONFIG_DTB_FILE config variable which should be set to the absolute path of the DTB. This variable may be set in <tt>.config</tt> or on the make command line. |
The DTB to use is specified by the CONFIG_DTB_FILE config variable which should be set to the absolute path of the DTB. This variable may be set in <tt>.config</tt> or on the make command line. |
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The Xen command line may be set with the <tt>bootargs</tt> parameter of the <tt>chosen</tt> node of the device tree. |
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== Dom0 kernel == |
== Dom0 kernel == |
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Enable at least ARCH_VEXPRESS, ARCH_VEXPRESS_DT, |
Enable at least ARCH_VEXPRESS, ARCH_VEXPRESS_DT, . Disable SPARSE_IRQ (it doesn't play nicely with device tree support). |
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A working configuration is available [http://xenbits.xen.org/people/dvrabel/xen-arm/vexpress-dt.config here]. |
A working configuration is available [http://xenbits.xen.org/people/dvrabel/xen-arm/vexpress-dt.config here]. |
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The Linux command line may be set with the <tt>xen,dom0-bootargs</tt> parameter of the <tt>chosen</tt> node of the device tree supplied to Xen. |
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=== Device Tree Blob (DTB) === |
=== Device Tree Blob (DTB) === |
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=== Flash Image === |
=== Flash Image === |
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The dom0 kernel is loaded by Xen from the beginning of the flash |
The dom0 kernel is loaded by Xen from the beginning of the flash. |
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=== Native boot === |
=== Native boot === |
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To boot the kernel natively use an updated boot-wrapper from [http://xenbits.xen.org/gitweb/?p=people/dvrabel/boot-wrapper.git;a=summary git://xenbits.xen.org/people/dvrabel/boot-wrapper.git]. |
To boot the kernel natively use an updated boot-wrapper from [http://xenbits.xen.org/gitweb/?p=people/dvrabel/boot-wrapper.git;a=summary git://xenbits.xen.org/people/dvrabel/boot-wrapper.git]. |
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For a native boot the kernel should have ARM_APPENDED_DTB and ARM_ATAG_DTB_COMPAT enabled. The kernel zImage and the DTB should be appended. e.g., <tt>cat zImage vexpress-v2p-aem-v7a.dtb > image.bin</tt>. |
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== Developer FAQs == |
== Developer FAQs == |
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Revision as of 16:45, 28 February 2012
The ARM v7-A architecture includes the optional virtualization extensions that allow a hypervisor to manage fully hardware virtualized guests. These extensions will be available in some ARM Cortex A15 and Cortex A7 processors.
This port is a work-in-progress and cannot yet start any guests (other than dom0).
Hardware
Currently there are no processors available which implement the virtualisation extensions. Therefore we are currently targetting the Real-time System Model's provided by ARM. See Xen ARMv7 with Virtualization Extensions/FastModels for more information on obtaining and building the necessary model.
Requirements
- ARM Fast Model
- Either the v7-A ARM Envelope Model (AEM) or the Cortex A15/A7 models (single CPU only).
- Device Tree
- A device tree in the flat device tree format (.dtb). The device tree source for the AEM is here: git://xenbits.xen.org/people/dvrabel/device-trees.git.
- Xen
- xen-unstable as of 1 Mar 2012.
- Linux kernel for dom0
- vexpress-dt branch of git://xenbits.xen.org/people/dvrabel/linux.git
- dom0 userspace
- (more details here)
Device Trees
Xen needs the device trees to be in the flat device tree format (the device tree blob or DTB). This is built by the device tree compiler (dtc) from the device tree source files (.dts and .dtsi.
Version 1.3 or later of dtc is required.
Build the .dtb files with make.
A pre-built vexpress-v2p-aem-v7a.dtb.
Xen
When running on the model there is no bootloader to provide the DTB. Instead, it is linked with the xen image.
The DTB to use is specified by the CONFIG_DTB_FILE config variable which should be set to the absolute path of the DTB. This variable may be set in .config or on the make command line.
The Xen command line may be set with the bootargs parameter of the chosen node of the device tree.
Dom0 kernel
Enable at least ARCH_VEXPRESS, ARCH_VEXPRESS_DT, . Disable SPARSE_IRQ (it doesn't play nicely with device tree support).
A working configuration is available here.
The Linux command line may be set with the xen,dom0-bootargs parameter of the chosen node of the device tree supplied to Xen.
Device Tree Blob (DTB)
Build the device tree blobs (flattened device tree binary files) with make dtbs. A suitable DTB file for the envelope model is vexpress-v2p-aem-v7a.dtb.
Flash Image
The dom0 kernel is loaded by Xen from the beginning of the flash.
Native boot
To boot the kernel natively use an updated boot-wrapper from git://xenbits.xen.org/people/dvrabel/boot-wrapper.git.
For a native boot the kernel should have ARM_APPENDED_DTB and ARM_ATAG_DTB_COMPAT enabled. The kernel zImage and the DTB should be appended. e.g., cat zImage vexpress-v2p-aem-v7a.dtb > image.bin.
Developer FAQs
Use the Xen ARMv7 Dev FAQ page to cover commonly asked questions.
