Re: Changing aarch64 pointer authentication algorithm in qemu-user

[Peter Maydell]

On Mon, 11 Apr 2022 at 11:05, Avi Kivity <avi@scylladb.com> wrote:
>
>
> On 11/04/2022 12.25, Peter Maydell wrote:
> > On Sun, 10 Apr 2022 at 21:03, Avi Kivity <avi@scylladb.com> wrote:
> >> I'm using qemu to cross-build container images with docker. It works
> >> well, but aarch64 emulation is slow, due to pointer authentication.
> >>
> >>
> >> The documentation refers to a pauth-impdef cpu feature to speed it up,
> >> but I could not find an example. What is the incantation?
> > "-cpu max,pauth-impdef=on" or similar should do.
>
>
> Thanks, subjectively feels much faster.
>
>
> In case someone googles this,
> https://github.com/avikivity/qemu-aarch64-static-fast can save you a bit
> of work.

For working via binfmt-misc the environment variable equivalents
for qemu-user-mode's command line arguments is often convenient.
In this case I think that ensuring that
QEMU_CPU="max,pauth-impdef=on"
is set in the environment would also work.

-- PMM