xref: /linux/Documentation/devicetree/bindings/arm/xen.txt (revision e7d759f31ca295d589f7420719c311870bb3166f)
1* Xen hypervisor device tree bindings
2
3Xen ARM virtual platforms shall have a top-level "hypervisor" node with
4the following properties:
5
6- compatible:
7	compatible = "xen,xen-<version>", "xen,xen";
8  where <version> is the version of the Xen ABI of the platform.
9
10- reg: specifies the base physical address and size of the regions in memory
11  where the special resources should be mapped to, using an HYPERVISOR_memory_op
12  hypercall.
13  Region 0 is reserved for mapping grant table, it must be always present.
14  The memory region is large enough to map the whole grant table (it is larger
15  or equal to gnttab_max_grant_frames()).
16  Regions 1...N are extended regions (unused address space) for mapping foreign
17  GFNs and grants, they might be absent if there is nothing to expose.
18
19- interrupts: the interrupt used by Xen to inject event notifications.
20  A GIC node is also required.
21
22To support UEFI on Xen ARM virtual platforms, Xen populates the FDT "uefi" node
23under /hypervisor with following parameters:
24
25________________________________________________________________________________
26Name                      | Size   | Description
27================================================================================
28xen,uefi-system-table     | 64-bit | Guest physical address of the UEFI System
29			  |	   | Table.
30--------------------------------------------------------------------------------
31xen,uefi-mmap-start       | 64-bit | Guest physical address of the UEFI memory
32			  |	   | map.
33--------------------------------------------------------------------------------
34xen,uefi-mmap-size        | 32-bit | Size in bytes of the UEFI memory map
35                          |        | pointed to in previous entry.
36--------------------------------------------------------------------------------
37xen,uefi-mmap-desc-size   | 32-bit | Size in bytes of each entry in the UEFI
38                          |        | memory map.
39--------------------------------------------------------------------------------
40xen,uefi-mmap-desc-ver    | 32-bit | Version of the mmap descriptor format.
41--------------------------------------------------------------------------------
42
43Example (assuming #address-cells = <2> and #size-cells = <2>):
44
45hypervisor {
46	compatible = "xen,xen-4.3", "xen,xen";
47	reg = <0 0xb0000000 0 0x20000>;
48	interrupts = <1 15 0xf08>;
49	uefi {
50		xen,uefi-system-table = <0xXXXXXXXX>;
51		xen,uefi-mmap-start = <0xXXXXXXXX>;
52		xen,uefi-mmap-size = <0xXXXXXXXX>;
53		xen,uefi-mmap-desc-size = <0xXXXXXXXX>;
54		xen,uefi-mmap-desc-ver = <0xXXXXXXXX>;
55        };
56};
57
58The format and meaning of the "xen,uefi-*" parameters are similar to those in
59Documentation/arch/arm/uefi.rst, which are provided by the regular UEFI stub. However
60they differ because they are provided by the Xen hypervisor, together with a set
61of UEFI runtime services implemented via hypercalls, see
62http://xenbits.xen.org/docs/unstable/hypercall/x86_64/include,public,platform.h.html.
63