Re: [Bug 1916112] Re: Illegal instruction crash of QEMU on Jetson Nano

[Stefan Weil]

Am 20.02.21 um 14:31 schrieb Stefan Weil:

> TCG works and I get a Linux boot prompt in the guest Raspbian when
> vector instructions for TCG are disabled, so obviously the undefined
> instruction is simply unsupported for Jetson Nano and Xavier.
>
> Patch used to disable it:
>
> diff --git a/tcg/aarch64/tcg-target.h b/tcg/aarch64/tcg-target.h
> index 5ec30dba25..2240adad1e 100644
> --- a/tcg/aarch64/tcg-target.h
> +++ b/tcg/aarch64/tcg-target.h
> @@ -125,8 +125,8 @@ typedef enum {
>   #define TCG_TARGET_HAS_mulsh_i64        1
>   #define TCG_TARGET_HAS_direct_jump      1
>   
> -#define TCG_TARGET_HAS_v64              1
> -#define TCG_TARGET_HAS_v128             1
> +#define TCG_TARGET_HAS_v64              0
> +#define TCG_TARGET_HAS_v128             0
>   #define TCG_TARGET_HAS_v256             0
>   
>   #define TCG_TARGET_HAS_andc_vec         1



cc'ing qemu-arm@nongnu.org

I think QEMU TCG for AARCH64 hosts needs a runtime check to decide which 
vector instructions are supported by the host (like it is done for 
AMD64). It currently fails because it generates instructions which are 
unknown for NVIDIA Jetson Nano and Xavier (Tegra CPU).

TCI works (now tested on Apple M1), too.

Stefan