Re: [Qemu-ppc] [Qemu-devel] [PATCH 3/3] target/ppc: filter out non-zero PCR values when using TCG

[Richard Henderson]

On 06/12/2018 10:19 PM, Greg Kurz wrote:
> I'm confused... I don't see anything related to HTM in TCG. Also we have
> the following in cap_htm_apply():
> 
>     if (tcg_enabled()) {
>         error_setg(errp,
>                    "No Transactional Memory support in TCG, try cap-htm=off");
> 
> I'm probably missing something... can you enlighten me ?

One of the two IBM machines -- and I thought it was ppc not s390x, but the code
you quote seems to deny that memory -- has stub support for TM within TCG.

To wit, the instructions are recognized and transactions always fail.  Which is
not a bad way to test the required fallback paths that rarely fail on hardware.
 ;-)


r~