On Tue, Jan 30, 2024 at 8:18 PM Björn Töpel <bjorn@xxxxxxxxxx> wrote: > > Björn Töpel <bjorn@xxxxxxxxxx> writes: > > > Anup Patel <apatel@xxxxxxxxxxxxxxxx> writes: > > > >> On Tue, Jan 30, 2024 at 1:22 PM Björn Töpel <bjorn@xxxxxxxxxx> wrote: > >>> > >>> Björn Töpel <bjorn@xxxxxxxxxx> writes: > >>> > >>> > Anup Patel <apatel@xxxxxxxxxxxxxxxx> writes: > >>> > > >>> >> The RISC-V AIA specification is ratified as-per the RISC-V international > >>> >> process. The latest ratified AIA specifcation can be found at: > >>> >> https://github.com/riscv/riscv-aia/releases/download/1.0/riscv-interrupts-1.0.pdf > >>> >> > >>> >> At a high-level, the AIA specification adds three things: > >>> >> 1) AIA CSRs > >>> >> - Improved local interrupt support > >>> >> 2) Incoming Message Signaled Interrupt Controller (IMSIC) > >>> >> - Per-HART MSI controller > >>> >> - Support MSI virtualization > >>> >> - Support IPI along with virtualization > >>> >> 3) Advanced Platform-Level Interrupt Controller (APLIC) > >>> >> - Wired interrupt controller > >>> >> - In MSI-mode, converts wired interrupt into MSIs (i.e. MSI generator) > >>> >> - In Direct-mode, injects external interrupts directly into HARTs > >>> >> > >>> >> For an overview of the AIA specification, refer the AIA virtualization > >>> >> talk at KVM Forum 2022: > >>> >> https://static.sched.com/hosted_files/kvmforum2022/a1/AIA_Virtualization_in_KVM_RISCV_final.pdf > >>> >> https://www.youtube.com/watch?v=r071dL8Z0yo > >>> >> > >>> >> To test this series, use QEMU v7.2 (or higher) and OpenSBI v1.2 (or higher). > >>> >> > >>> >> These patches can also be found in the riscv_aia_v12 branch at: > >>> >> https://github.com/avpatel/linux.git > >>> >> > >>> >> Changes since v11: > >>> >> - Rebased on Linux-6.8-rc1 > >>> >> - Included kernel/irq related patches from "genirq, irqchip: Convert ARM > >>> >> MSI handling to per device MSI domains" series by Thomas. > >>> >> (PATCH7, PATCH8, PATCH9, PATCH14, PATCH16, PATCH17, PATCH18, PATCH19, > >>> >> PATCH20, PATCH21, PATCH22, PATCH23, and PATCH32 of > >>> >> https://lore.kernel.org/linux-arm-kernel/20221121135653.208611233@xxxxxxxxxxxxx/) > >>> >> - Updated APLIC MSI-mode driver to use the new WIRED_TO_MSI mechanism. > >>> >> - Updated IMSIC driver to support per-device MSI domains for PCI and > >>> >> platform devices. > >>> > > >>> > Thanks for working on this, Anup! I'm still reviewing the patches. > >>> > > >>> > I'm hitting a boot hang in text patching, with this series applied on > >>> > 6.8-rc2. IPI issues? > >>> > >>> Not text patching! One cpu spinning in smp_call_function_many_cond() and > >>> the others are in cpu_relax(). Smells like IPI... > >> > >> I tried bootefi from U-Boot multiple times but can't reproduce the > >> issue you are seeing. > > > > Thanks! I can reproduce without EFI, and simpler command-line: > > > > qemu-system-riscv64 \ > > -bios /path/to/fw_dynamic.bin \ > > -kernel /path/to/Image \ > > -append 'earlycon console=tty0 console=ttyS0' \ > > -machine virt,aia=aplic-imsic \ > > -no-reboot -nodefaults -nographic \ > > -smp 4 \ > > -object rng-random,filename=/dev/urandom,id=rng0 \ > > -device virtio-rng-device,rng=rng0 \ > > -m 4G -chardev stdio,id=char0 -serial chardev:char0 > > > > I can reproduce with your upstream riscv_aia_v12 plus the config in the > > gist [1], and all latest QEMU/OpenSBI: > > > > QEMU: 11be70677c70 ("Merge tag 'pull-vfio-20240129' of https://github.com/legoater/qemu into staging") > > OpenSBI: bb90a9ebf6d9 ("lib: sbi: Print number of debug triggers found") > > Linux: d9b9d6eb987f ("MAINTAINERS: Add entry for RISC-V AIA drivers") > > > > Removing ",aia=aplic-imsic" from the CLI above completes the boot (i.e. > > panicking about missing root mount ;-)) > > More context; The hang is during a late initcall, where an ftrace direct > (register_ftrace_direct()) modification is done. > > Stop machine is used to call into __ftrace_modify_call(). Then into the > arch specific patch_text_nosync(), where flush_icache_range() hangs in > flush_icache_all(). From "on_each_cpu(ipi_remote_fence_i, NULL, 1);" to > on_each_cpu_cond_mask() "smp_call_function_many_cond(mask, func, info, > scf_flags, cond_func);" which never returns from "csd_lock_wait(csd)" > right before the end of the function. > > Any ideas? Disabling CONFIG_HID_BPF, that does the early ftrace code > patching fixes the boot hang, but it does seem related to IPI... > Looks like flush_icache_all() does not use the IPIs (on_each_cpu() and friends) correctly. On other hand, the flush_icache_mm() does the right thing by doing local flush on the current CPU and IPI based flush on other CPUs. Can you try the following patch ? diff --git a/arch/riscv/mm/cacheflush.c b/arch/riscv/mm/cacheflush.c index 55a34f2020a8..a3dfbe4de832 100644 --- a/arch/riscv/mm/cacheflush.c +++ b/arch/riscv/mm/cacheflush.c @@ -19,12 +19,18 @@ static void ipi_remote_fence_i(void *info) void flush_icache_all(void) { + cpumask_t others; + local_flush_icache_all(); + cpumask_andnot(&others, cpu_online_mask, cpumask_of(smp_processor_id())); + if (cpumask_empty(&others)) + return; + if (IS_ENABLED(CONFIG_RISCV_SBI) && !riscv_use_ipi_for_rfence()) - sbi_remote_fence_i(NULL); + sbi_remote_fence_i(&others); else - on_each_cpu(ipi_remote_fence_i, NULL, 1); + on_each_cpu_mask(&others, ipi_remote_fence_i, NULL, 1); } EXPORT_SYMBOL(flush_icache_all); Regards, Anup
