Hi, Mike, On Mon, May 25, 2026 at 3:48 PM Mike Rapoport <[email protected]> wrote: > > On Mon, 25 May 2026 14:28:03 +0800, George Guo <[email protected]> wrote: > > Hi, > > > [...] > > > > 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. > > This fix looks unrelated to KHO, it makes sense to send it as a separate > patch. He tried, but it causes new problems, but I agree this patch has nothing to do with KHO. https://lore.kernel.org/loongarch/[email protected]/T/#t
> > > > > 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 > > And I believe that patch 2 and patch 4 can be folded into patch 1 so > that addition of KHO support will be a single patch. Patch 2 should be folded, but Patch 4 can be separate, because it should be backported. > > > 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. > > This should be folded into patch 5 for sure. I completely don't know why Patch 6 is needed, for normal use I8042 doesn't cause problems in virtual machines. Huacai > > > > > 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. > > And since without this selftest would hang on loongarch, the timeout > handing should be folded into patch 5. > > In general, the rationale when adding new features is to make sure that > after each patch there are no regressions and the new functionality > either works or cannot be enabled until completely implemented. > > -- > Sincerely yours, > Mike. >
