Re: [PATCH v2] target/ppc: Fix BookE debug interrupt generation

[Fabiano Rosas]

Bin Meng <bmeng.cn@gmail.com> writes:

> From: Bin Meng <bin.meng@windriver.com>
>
> Per E500 core reference manual [1], chapter 8.4.4 "Branch Taken Debug
> Event" and chapter 8.4.5 "Instruction Complete Debug Event":
>
>   "A branch taken debug event occurs if both MSR[DE] and DBCR0[BRT]
>   are set ... Branch taken debug events are not recognized if MSR[DE]
>   is cleared when the branch instruction executes."
>
>   "An instruction complete debug event occurs when any instruction
>   completes execution so long as MSR[DE] and DBCR0[ICMP] are both
>   set ... Instruction complete debug events are not recognized if
>   MSR[DE] is cleared at the time of the instruction execution."
>
> Current codes do not check MSR.DE bit before setting HFLAGS_SE and
> HFLAGS_BE flag, which would cause the immediate debug interrupt to
> be generated, e.g.: when DBCR0.ICMP bit is set by guest software
> and MSR.DE is not set.
>
> [1] https://www.nxp.com/docs/en/reference-manual/E500CORERM.pdf
>
> Signed-off-by: Bin Meng <bin.meng@windriver.com>

Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>