(*)QEMU RV32 virt pc:
https://github.com/zephyrproject-rtos/zephyr/pull/28749

That PR looks fine. But you definitely will have some work to do to get SMP working on Risc-V, starting with changing the arch to select CONFIG_SWITCH, and then implement arch_start_cpu(), arch_curr_cpu(), etc.

But I don't understand Zephyr's SMP mechanism perfectly and don't know
required conditions (Ex. regression tests) if I want to change these area.

There are an assortment of tests with 'smp' in their tags, defined by testcase.yaml.

So you can do:

sanitycheck -p <your target name> -t smp

To quickly run these.

HTH
Andrew

-----Original Message-----
From: devel@lists.zephyrproject.org <devel@lists.zephyrproject.org> On
Behalf Of Katsuhiro Suzuki
Sent: Tuesday, October 6, 2020 1:54 AM
To: zephyr-devel <zephyr-devel@lists.zephyrproject.org>
Subject: [Zephyr-devel] [RFC] SMP support for RISC-V privilege architecture

Hello All,

I'm working on SMP support for RISC-V privilege architecture.
https://github.com/katsuster/zephyr/tree/riscv_virt_pc_smp

It seems worked well on QEMU RV32 virt pc (*) porting.
(RV64 not tested yet)

But I don't understand Zephyr's SMP mechanism perfectly and don't know
required conditions (Ex. regression tests) if I want to change these area.

I'm welcome comments or review of my patch.



Command line:
qemu-system-riscv32 -nographic -machine virt -net none \
-chardev stdio,id=con,mux=on -serial chardev:con \
-mon chardev=con,mode=readline -kernel zephyr/zephyr.elf \
-cpu rv32 -smp cpus=4 -bios none

Best Regards,
Katsuhiro Suzuki