[PATCH v3 0/1] Add support for generating OpenSBI domains in the device tree

[Gregor Haas <gregorhaas1997@gmail.com>]

This patch series adds support for specifying OpenSBI domains on the QEMU
command line. A simple example of what this looks like is below, including
mapping the board's UART into the secondary domain:

qemu-system-riscv64 -machine virt -bios fw_jump.bin -cpu max -smp 2 -m 4G -nographic \
        -device opensbi-memregion,id=mem,base=0xBC000000,order=26,mmio=false \
        -device opensbi-memregion,id=uart,base=0x10000000,order=12,mmio=true,device0="/soc/serial@10000000" \
        -device opensbi-domain,id=domain,possible-harts=0-1,boot-hart=0x0,next-addr=0xBC000000,next-mode=1,region0=mem,perms0=0x3f,region1=uart,perms1=0x3f

As a result of the above configuration, QEMU will add the following subnodes to
the device tree:

chosen {
        opensbi-domains {
                compatible = "opensbi,domain,config";

                domain {
                        next-mode = <0x01>;
                        next-addr = <0x00 0xbc000000>;
                        boot-hart = <0x03>;
                        regions = <0x8000 0x3f 0x8002 0x3f>;
                        possible-harts = <0x03 0x01>;
                        phandle = <0x8003>;
                        compatible = "opensbi,domain,instance";
                };

                uart {
                        phandle = <0x8002>;
                        devices = <0x1800000>;
                        mmio;
                        order = <0x0c>;
                        base = <0x00 0x10000000>;
                        compatible = "opensbi,domain,memregion";
                };

                mem {
                        phandle = <0x8000>;
                        order = <0x1a>;
                        base = <0x00 0xbc000000>;
                        compatible = "opensbi,domain,memregion";
                };
        };
};

This results in OpenSBI output as below, where regions 01-03 are inherited from
the root domain and regions 00 and 04 correspond to the user specified ones:

Domain1 Name              : domain
Domain1 Boot HART         : 0
Domain1 HARTs             : 0,1
Domain1 Region00          : 0x0000000010000000-0x0000000010000fff M: (I,R,W,X) S/U: (R,W,X)
Domain1 Region01          : 0x0000000002000000-0x000000000200ffff M: (I,R,W) S/U: ()
Domain1 Region02          : 0x0000000080080000-0x000000008009ffff M: (R,W) S/U: ()
Domain1 Region03          : 0x0000000080000000-0x000000008007ffff M: (R,X) S/U: ()
Domain1 Region04          : 0x00000000bc000000-0x00000000bfffffff M: (R,W,X) S/U: (R,W,X)
Domain1 Next Address      : 0x00000000bc000000
Domain1 Next Arg1         : 0x0000000000000000
Domain1 Next Mode         : S-mode
Domain1 SysReset          : no
Domain1 SysSuspend        : no

v3:
- Addressed review comments from v2 by adding default values to new properties.
  This results in concrete errors at QEMU configuration time if a mandatory
  property (as mandated by the OpenSBI spec) is not provided.
- Changed command line encoding for the possible-harts field from a CPU bitmask
  (e.g. where bit X is set if CPU X is a possible hart) to a range format (e.g.
  the possible harts should be CPUs X-Y, where Y >= X). This does constrain the
  hart assignment to consecutive ranges of harts, but this constraint is also
  present for other QEMU subsystems (such as NUMA).
- Added create_fdt_one_device(), which is invoked when scanning the device tree
  for a memregion's devices. This function allocates a phandle for a region's
  device if one does not yet exist.

v2:
- Addressed review comments from v1. Specifically, renamed domain.{c,h} ->
  opensbi_domain.{c,h} to increase clarity of what these files do. Also, more
  consistently use g_autofree for dynamically allocated variables
- Added an "assign" flag to OpenSBIDomainState, which indicates whether to
  assign the domain's boot hart to it at domain parsing time.

Gregor Haas (1):
  Add support for generating OpenSBI domains in the device tree

 MAINTAINERS                       |   7 +
 hw/riscv/Kconfig                  |   4 +
 hw/riscv/meson.build              |   1 +
 hw/riscv/opensbi_domain.c         | 542 ++++++++++++++++++++++++++++++
 hw/riscv/virt.c                   |   3 +
 include/hw/riscv/opensbi_domain.h |  50 +++
 6 files changed, 607 insertions(+)
 create mode 100644 hw/riscv/opensbi_domain.c
 create mode 100644 include/hw/riscv/opensbi_domain.h

-- 
2.45.2