Re: [PATCH] target/arm: trap DCC access in user mode emulation

[Peter Maydell]

On Sat, 3 Jun 2023 at 05:52, Richard Henderson
<richard.henderson@linaro.org> wrote:
>
> On 6/2/23 14:43, Zhuojia Shen wrote:
> > Accessing EL0-accessible Debug Communication Channel (DCC) registers in
> > user mode emulation is currently enabled.  However, it does not match
> > Linux behavior as Linux sets MDSCR_EL1.TDCC on startup to disable EL0
> > access to DCC (see __cpu_setup() in arch/arm64/mm/proc.S).
> >
> > This patch fixes access_tdcc() to check MDSCR_EL1.TDCC for EL0 and sets
> > MDSCR_EL1.TDCC for user mode emulation to match Linux.
> >
> > Signed-off-by: Zhuojia Shen <chaosdefinition@hotmail.com>
>
> It would be nice to define the fields of MDSCR properly but either way,
>
> Reviewed-by: Richard Henderson <richard.henderson@linaro.org>



Applied to target-arm.next, thanks.

-- PMM