2025-09-29T11:48:08+10:00, Alistair Francis <[email protected]>:
> On Mon, Sep 15, 2025 at 5:08 PM Xie Bo <[email protected]> wrote:
>>
>> For KVM mode, the privilege mode should not include M-mode, and the
>> initial value should be set to S-mode. Additionally, a following patch
>> adds the implementation of putting the vCPU privilege mode to KVM.
>> When the vCPU runs for the first time, QEMU will first put the privilege
>> state to KVM. If the initial value is set to M-mode, KVM will encounter
>> an error.
>>
>> In addition, this patch introduces the 'mp_state' field to RISC-V
>> vCPUs, following the convention used by KVM on x86. The 'mp_state'
>> reflects the multiprocessor state of a vCPU, and is used to control
>> whether the vCPU is runnable by KVM. Randomly select one CPU as the
>> boot CPU. Since each CPU executes the riscv_cpu_reset_hold() function
>> and CPU0 executes first, only CPU0 randomly selects the boot CPU.
>>
>> Signed-off-by: Xie Bo <[email protected]>
>> ---
>> target/riscv/cpu.c | 17 ++++++++++++++++-
>> target/riscv/cpu.h | 2 ++
>> 2 files changed, 18 insertions(+), 1 deletion(-)
>
> This fails to build with the following error, it seems an include is missing
>
> ../target/riscv/cpu.c: In function ‘riscv_cpu_reset_hold’:
> ../target/riscv/cpu.c:711:25: error: ‘KVM_MP_STATE_RUNNABLE’
> undeclared (first use in this function)
> 711 | env->mp_state = KVM_MP_STATE_RUNNABLE;
> | ^~~~~~~~~~~~~~~~~~~~~
> ../target/riscv/cpu.c:711:25: note: each undeclared identifier is
> reported only once for each function it appears in
> ../target/riscv/cpu.c:713:25: error: ‘KVM_MP_STATE_STOPPED’ undeclared
> (first use in this function); did you mean ‘S390_CPU_STATE_STOPPED’?
> 713 | env->mp_state = KVM_MP_STATE_STOPPED;
> | ^~~~~~~~~~~~~~~~~~~~
> | S390_CPU_STATE_STO
I think this is because the code belongs in kvm_riscv_reset_vcpu().
>> diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
>> + static int boot_cpu_index;
>> + MachineState *ms = MACHINE(qdev_get_machine());
>> + if (cs->cpu_index == 0) {
>> + boot_cpu_index = g_random_int_range(0, ms->smp.cpus);
>> + }
If we're already touching the code, can we also express boot_cpu_index
in a VM state? Using a static variable is pretty scary.
Thanks.
