Re: [PATCH v4 2/5] docs/about/deprecated: Deprecate the qemu-system-i386 binary

[Thomas Huth]

On 06/03/2023 10.27, Daniel P. Berrangé wrote:
> On Mon, Mar 06, 2023 at 09:46:55AM +0100, Thomas Huth wrote:
> > [...] If a 32-bit CPU guest
> > +environment should be enforced, you can switch off the "long mode" CPU
> > +flag, e.g. with ``-cpu max,lm=off``.
>
> I had the idea to check this today and this is not quite sufficient,
[...]
> A further difference is that qemy-system-i686 does not appear to enable
> the 'syscall' flag, but I've not figured out where that difference is
> coming from in the code.

I think I just spotted this by accident in target/i386/cpu.c
around line 637:

#ifdef TARGET_X86_64
#define TCG_EXT2_X86_64_FEATURES (CPUID_EXT2_SYSCALL | CPUID_EXT2_LM)
#else
#define TCG_EXT2_X86_64_FEATURES 0
#endif

 Thomas