Re: [PATCH 2/2] hw/riscv/virt.c: fix non-KVM --enable-debug build

[Richard Henderson <richard.henderson@linaro.org>]

On 8/29/23 16:09, Daniel Henrique Barboza wrote:
>> -- >8 --
>> diff --git a/hw/riscv/virt.c b/hw/riscv/virt.c
>> @@ -79,7 +79,9 @@
>>   /* KVM AIA only supports APLIC MSI. APLIC Wired is always emulated by QEMU. */
>>   static bool virt_use_kvm_aia(RISCVVirtState *s)
>>   {
>> -    return kvm_irqchip_in_kernel() && s->aia_type == VIRT_AIA_TYPE_APLIC_IMSIC;
>> +    return kvm_enabled()
>> +        && kvm_irqchip_in_kernel()
>> +        && s->aia_type == VIRT_AIA_TYPE_APLIC_IMSIC;
>>   }
>> ---
> 
> It doesn't work. Same error:
> 
> diff --git a/hw/riscv/virt.c b/hw/riscv/virt.c
> index 388e52a294..ac710006e7 100644
> --- a/hw/riscv/virt.c
> +++ b/hw/riscv/virt.c
> @@ -79,7 +79,8 @@
>   /* KVM AIA only supports APLIC MSI. APLIC Wired is always emulated by QEMU. */
>   static bool virt_use_kvm_aia(RISCVVirtState *s)
>   {
> -    return kvm_irqchip_in_kernel() && s->aia_type == VIRT_AIA_TYPE_APLIC_IMSIC;
> +    return kvm_enabled() &&
> +           kvm_irqchip_in_kernel() && s->aia_type == VIRT_AIA_TYPE_APLIC_IMSIC;
>   }
> 
>   static const MemMapEntry virt_memmap[] = {
> diff --git a/target/riscv/kvm_riscv.h b/target/riscv/kvm_riscv.h
> index 01be45cc69..7d4b7c60e2 100644
> --- a/target/riscv/kvm_riscv.h
> +++ b/target/riscv/kvm_riscv.h
> @@ -22,19 +22,9 @@
>   void kvm_riscv_init_user_properties(Object *cpu_obj);
>   void kvm_riscv_reset_vcpu(RISCVCPU *cpu);
>   void kvm_riscv_set_irq(RISCVCPU *cpu, int irq, int level);
> -
> -#ifdef CONFIG_KVM
>   void kvm_riscv_aia_create(MachineState *machine, uint64_t group_shift,
>                             uint64_t aia_irq_num, uint64_t aia_msi_num,
>                             uint64_t aplic_base, uint64_t imsic_base,
>                             uint64_t guest_num);
> -#else
> -static inline void kvm_riscv_aia_create(MachineState *machine,
> -                                uint64_t group_shift, uint64_t aia_irq_num,
> -                                uint64_t aia_msi_num, uint64_t aplic_base,
> -                                uint64_t imsic_base, uint64_t guest_num) {
> -    g_assert_not_reached();
> -}
> -#endif
> 
> 
> 
> /usr/bin/ld: libqemu-riscv64-softmmu.fa.p/hw_riscv_virt.c.o: in function `virt_machine_init':
> /home/danielhb/work/qemu/build/../hw/riscv/virt.c:1466: undefined reference to 
> `kvm_riscv_aia_create'
> collect2: error: ld returned 1 exit status
> 
> 
> I'm no compiler expert by any means but it seems that the --enable-debug build does not 
> strip things
> out like the usual build does, e.g. it won't elide a 'if kvm_enabled()' block out by 
> checking that
> kvm_enabled() is always false.

The compiler certainly does eliminate 0 && foo(), even at -O0.

There must be something else going on.
Pointer to your tree?

r~