[kvm-unit-tests PATCH 0/7] riscv: ACPI boot and BRS-I SBI tests

[Xiang W]

Hi,

This series lets RISC-V kvm-unit-tests boot on BRS-I platforms that
describe the system with UEFI + ACPI instead of a device tree, and adds
a first unit test for the SBI rules in the RISC-V Boot and Runtime
Services specification [1].

The RISC-V port currently assumes a DT for CPU bring-up, timer
frequency, ISA-string parsing and console setup. BRS-I firmware
typically does not provide a usable DT, and often has no MMIO UART
either. Without these changes the existing tests abort in setup before
they can exercise SBI.

Patches 1-4 teach the RISC-V library to initialize from ACPI when a DT
is absent:

  - locate the ACPI 2.0 RSDP via the EFI configuration table
  - parse MADT RINTC entries for hart / CPU bring-up
  - read the timebase frequency from RHCT
  - parse the ISA string from RHCT Hart Info nodes (match by ACPI UID)

The RSDP is left in EFI_ACPI_RECLAIM_MEMORY; the RISC-V allocator does
not reuse that region, so the table is not copied aside.

Patch 5 splits CONFIG_SBI_CONSOLE out of the UART driver. io_init()
becomes a no-op and puts() issues SBI DBCN CONSOLE_WRITE directly, so
EFI/ACPI guests no longer depend on a described MMIO UART to print.

Patch 6 drops the EFI runner's EFI_USE_ACPI=y early exit. The runner
already omits -machine acpi=off in that case; QEMU virt defaults to
ACPI enabled.

Patch 7 adds riscv/riscv-brs.c for:

  SBI_010  spec version >= 2.0
  SBI_020  HSM required
  SBI_030  TIME required unless Sstc
  SBI_040  IPI required unless Ssaia
  SBI_050  RFENCE required unless Ssaia
  SBI_060  PMU required unless Smcsrind + Sscsrind + Smcdeleg + Ssccfg
  SBI_070  DBCN required when ACPI SPCR Interface Type is 0x15

The new test is in group "riscv-brs nodefault", so it is not part of
the default run_tests.sh pass. DT-only QEMU virt is unchanged.

Based on kvm-unit-tests master (5a221342).

[1] https://github.com/riscv-non-isa/riscv-brs

Testing
=======
Build:

  ./configure --arch=riscv64 \
              --cross-prefix=riscv64-linux-gnu- \
              --console=sbi --enable-efi && make

EFI + ACPI (BRS-I style):

  EFI_USE_ACPI=y EFI_UEFI=/path/to/RISCV_VIRT_CODE.fd \
    ./riscv/efi/run riscv/riscv-brs.efi

Please review.

Xiang W (7):
  riscv: Initialize the ACPI RSDP from the EFI system table
  riscv: Add ACPI support for CPU initialization
  riscv: Add ACPI support for timer frequency discovery
  riscv: Add ACPI support for ISA string discovery
  riscv: Decouple SBI console from UART init
  riscv: efi: Allow ACPI boots
  riscv: Add BRS SBI requirement tests

 lib/acpi.h                |  67 ++++++++++++++-
 lib/riscv/asm/isa.h       |   5 ++
 lib/riscv/asm/processor.h |   1 +
 lib/riscv/asm/sbi.h       |   2 +
 lib/riscv/io.c            |  50 +++++------
 lib/riscv/isa.c           |  82 ++++++++++++++++--
 lib/riscv/setup.c         |  55 ++++++++++++
 lib/riscv/timer.c         |  37 ++++++---
 riscv/Makefile            |   1 +
 riscv/efi/run             |   5 --
 riscv/riscv-brs.c         | 171 ++++++++++++++++++++++++++++++++++++++
 riscv/unittests.cfg       |   4 +
 12 files changed, 424 insertions(+), 56 deletions(-)
 create mode 100644 riscv/riscv-brs.c

-- 
2.47.3