Re: [Qemu-devel] [PATCH] target-i386: Enhance the stub for kvm_arch_get_supported_cpuid()

[Kamil Rytarowski]

Ping?

On 02.02.2019 15:45, Kamil Rytarowski wrote:
> This improves the commit:
> "target-i386: Fix build by providing stub kvm_arch_get_supported_cpuid()"
> r. 2140cfa51d59177815f5b82e94ac48fb24909aba
> 
> Clang/LLVM on NetBSD with enabled optimization cannot link
> correct qemu program because of a missing symbol of
> kvm_arch_get_supported_cpuid() in kvm-stubs.o used by executables.
> 
> There are more than a single one kvm-stub.c and several types
> of possible programs such as bsd-user ones. the previous workaround
> does not work reliably for all use-cases. Instead of reworking
> the stubs and linking rules, move the workaround from a code that
> depends on the __OPTIMIZE__ builtin compiler flag, build option (KVM),
> compiler and arrangement of linking rules to a simple macro in a
> shared header with all the users that defines fallback dummy
> implementation, ignoring whether it is optimized out or not.
> 
> Signed-off-by: Kamil Rytarowski <address@hidden>
> ---
>  include/sysemu/kvm.h   | 13 +++++++++++++
>  target/i386/kvm-stub.c | 10 ----------
>  2 files changed, 13 insertions(+), 10 deletions(-)
> 
> diff --git a/include/sysemu/kvm.h b/include/sysemu/kvm.h
> index a6d1cd190f..93d3c0f0b3 100644
> --- a/include/sysemu/kvm.h
> +++ b/include/sysemu/kvm.h
> @@ -459,8 +459,21 @@ int kvm_vm_check_extension(KVMState *s, unsigned int 
> extension);
>          kvm_vcpu_ioctl(cpu, KVM_ENABLE_CAP, &cap);                   \
>      })
>  
> +#ifdef CONFIG_KVM
>  uint32_t kvm_arch_get_supported_cpuid(KVMState *env, uint32_t function,
>                                        uint32_t index, int reg);
> +#else
> +/*
> + * This function is only called inside conditionals which we
> + * rely on the compiler to optimize out when CONFIG_KVM is not
> + * defined.
> + */
> +#define kvm_arch_get_supported_cpuid(a, b, c, d)                     \
> +    ({                                                               \
> +        abort();                                                     \
> +        0;                                                           \
> +    })
> +#endif
>  uint32_t kvm_arch_get_supported_msr_feature(KVMState *s, uint32_t index);
>  
>  
> diff --git a/target/i386/kvm-stub.c b/target/i386/kvm-stub.c
> index e7a673e5db..9ce8566700 100644
> --- a/target/i386/kvm-stub.c
> +++ b/target/i386/kvm-stub.c
> @@ -29,16 +29,6 @@ bool kvm_enable_x2apic(void)
>  {
>      return false;
>  }
> -
> -/* This function is only called inside conditionals which we
> - * rely on the compiler to optimize out when CONFIG_KVM is not
> - * defined.
> - */
> -uint32_t kvm_arch_get_supported_cpuid(KVMState *env, uint32_t function,
> -                                      uint32_t index, int reg)
> -{
> -    abort();
> -}
>  #endif
>  
>  bool kvm_hv_vpindex_settable(void)
>

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