From: George Guo <[email protected]>> This series adds Kexec Handover (KHO) support for LoongArch64 and extends the KHO selftest infrastructure to run on LoongArch under QEMU.
KHO support (patches 1-2) -------------------------- Patch 1 wires up the three pieces needed for KHO on LoongArch: - Kconfig: select ARCH_SUPPORTS_KEXEC_HANDOVER for 64BIT - machine_kexec_file: call cmdline_add_kho() to pass the KHO FDT and scratch buffer addresses via "kho_handover=" on the kernel cmdline - setup: parse "kho_handover=" early and call kho_populate() Patch 2 fixes a duplicate-parameter bug when kexec is invoked with --reuse-cmdline: the running kernel's cmdline already contains a stale kho_handover= from the previous load. load_other_segments() prepends a fresh entry but appends the original cmdline verbatim, so early_param() calls kho_populate() twice and the second call overwrites the first with a stale FDT pointer, panicking early in mm_core_init(). Bug fixes (patches 3-4) ------------------------ Patch 3 fixes a build failure with CONFIG_KFENCE=y: virt_to_phys() and phys_to_virt() in asm/io.h expand to use offset_in_page() and page_address(), which require <linux/mm.h> that was not included. Patch 4 moves KEXEC_CONTROL_CODE from 0x100000 to 0x180000. QEMU places its machine FDT at 0x100000 when booting with '-kernel'; the previous placement silently overwrote the FDT with the relocation trampoline, breaking earlycon in the kexec'd kernel. Selftest support (patches 5-7) ------------------------------- Patch 5 adds loongarch.conf and extends vmtest.sh to recognise loongarch64 as a build target. QEMU's LoongArch virt machine is FDT-only (no ACPI), so 'earlycon' must appear on the kernel cmdline or the console UART is never discovered and the test log stays empty. Patch 6 disables SERIO_I8042 and its dependents in the QEMU_KCONFIG fragment. QEMU's LoongArch virt machine has no i8042 controller; the fallback port probe hits a page fault on the memory-mapped I/O range and panics before reaching userspace. Patch 7 polls the serial output for the test verdict and kills QEMU once it appears. QEMU provides no EFI runtime services on LoongArch, so machine_restart() falls through to an infinite idle loop and QEMU never exits after kexec. George Guo (7): LoongArch: Add KHO basic support LoongArch: kho: strip stale kho_handover= from reused cmdline LoongArch: Add missing linux/mm.h include in asm/io.h LoongArch: kexec: avoid overwriting QEMU's machine FDT at 0x100000 selftests/kho: add LoongArch vmtest support selftests/kho: LoongArch: disable PS/2 input devices for QEMU virt selftests/kho: handle QEMU not exiting after kexec on LoongArch arch/loongarch/Kconfig | 3 ++ arch/loongarch/include/asm/io.h | 1 + arch/loongarch/kernel/machine_kexec.c | 9 +++- arch/loongarch/kernel/machine_kexec_file.c | 57 ++++++++++++++++++++++ arch/loongarch/kernel/setup.c | 27 ++++++++++ tools/testing/selftests/kho/loongarch.conf | 10 ++++ tools/testing/selftests/kho/vmtest.sh | 38 ++++++++++++--- 7 files changed, 135 insertions(+), 10 deletions(-) create mode 100644 tools/testing/selftests/kho/loongarch.conf -- 2.25.1
