Re: [PATCH 1/1] target/riscv: Fix VS mode interrupts forwarding.

[Rajnesh Kanwal]

Hello Jose,

Sorry I didn't see that as it hadn't became a part of the port. I don't know how

they proceed with same patches.

Just to add, there is a minor problem with your patch. The cause value should
only be decremented by one for VS mode interrupts. In case if hypervisor has

delegated S mode interrupts then we should not decrement cause for those

interrupts.

Regards,

Rajnesh

On Sun, Feb 23, 2020 at 7:41 PM Jose Martins <address@hidden> wrote:

Hello rajnesh,

I had already submitted almost this exact patch a few weeks ago.

Jose

On Sun, 23 Feb 2020 at 13:51, <address@hidden> wrote:
>
> From: Rajnesh Kanwal <address@hidden>
>
> Currently riscv_cpu_local_irq_pending is used to find out pending
> interrupt and VS mode interrupts are being shifted to represent
> S mode interrupts in this function. So when the cause returned by
> this function is passed to riscv_cpu_do_interrupt to actually
> forward the interrupt, the VS mode forwarding check does not work
> as intended and interrupt is actually forwarded to hypervisor. This
> patch fixes this issue.
>
> Signed-off-by: Rajnesh Kanwal <address@hidden>
> ---
>  target/riscv/cpu_helper.c | 9 ++++++++-
>  1 file changed, 8 insertions(+), 1 deletion(-)
>
> diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
> index b9e90dfd9a..59535ecba6 100644
> --- a/target/riscv/cpu_helper.c
> +++ b/target/riscv/cpu_helper.c
> @@ -46,7 +46,7 @@ static int riscv_cpu_local_irq_pending(CPURISCVState *env)
>      target_ulong pending = env->mip & env->mie &
>                                 ~(MIP_VSSIP | MIP_VSTIP | MIP_VSEIP);
>      target_ulong vspending = (env->mip & env->mie &
> -                              (MIP_VSSIP | MIP_VSTIP | MIP_VSEIP)) >> 1;
> +                              (MIP_VSSIP | MIP_VSTIP | MIP_VSEIP));
>
>      target_ulong mie    = env->priv < PRV_M ||
>                            (env->priv == PRV_M && mstatus_mie);
> @@ -900,6 +900,13 @@ void riscv_cpu_do_interrupt(CPUState *cs)
>
>              if (riscv_cpu_virt_enabled(env) && ((hdeleg >> cause) & 1) &&
>                  !force_hs_execp) {
> +                /*
> +                 * See if we need to adjust cause. Yes if its VS mode interrupt
> +                 * no if hypervisor has delegated one of hs mode's interrupt
> +                 */
> +                if (cause == IRQ_VS_TIMER || cause == IRQ_VS_SOFT ||
> +                    cause == IRQ_VS_EXT)
> +                    cause = cause - 1;
>                  /* Trap to VS mode */
>              } else if (riscv_cpu_virt_enabled(env)) {
>                  /* Trap into HS mode, from virt */
> --
> 2.17.1
>
>