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

[Fabiano Rosas <farosas@linux.ibm.com>]

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

> From: Bin Meng <bin.meng@windriver.com>
>
> Per PowerISA v2.07 [1], Book III-E, chapter 7.6 "Interrupt definitions"

Which BookE board are you concerned about? I don't think we have any
BookE ISA v2.07 in QEMU currently.

> "When in Internal Debug Mode with MSR.DE=0, then Instruction Complete
> and Branch Taken debug events cannot occur, and no DBSR status bits
> are set and no subsequent imprecise Debug interrupt will occur."
>
> 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.
>

The rationale and the change itself look ok.

> [1] https://ibm.ent.box.com/s/jd5w15gz301s5b5dt375mshpq9c3lh4u
>
> Signed-off-by: Bin Meng <bin.meng@windriver.com>
> ---
>
>  target/ppc/helper_regs.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/target/ppc/helper_regs.c b/target/ppc/helper_regs.c
> index 9a691d6833..77bc57415c 100644
> --- a/target/ppc/helper_regs.c
> +++ b/target/ppc/helper_regs.c
> @@ -63,10 +63,10 @@ static uint32_t hreg_compute_hflags_value(CPUPPCState *env)
>  
>      if (ppc_flags & POWERPC_FLAG_DE) {
>          target_ulong dbcr0 = env->spr[SPR_BOOKE_DBCR0];
> -        if (dbcr0 & DBCR0_ICMP) {
> +        if ((dbcr0 & DBCR0_ICMP) && msr_de) {
>              hflags |= 1 << HFLAGS_SE;
>          }
> -        if (dbcr0 & DBCR0_BRT) {
> +        if ((dbcr0 & DBCR0_BRT) && msr_de) {
>              hflags |= 1 << HFLAGS_BE;
>          }
>      } else {