Re: [PATCH] pnv_lpc: disable reentrancy detection for lpc-hc

[Cédric Le Goater]

Hello Alexander

On 5/11/23 10:53, Alexander Bulekov wrote:
> As lpc-hc is designed for re-entrant calls from xscom, mark it
> re-entrancy safe.
>
> Reported-by: Thomas Huth <thuth@redhat.com>
> Signed-off-by: Alexander Bulekov <alxndr@bu.edu>
> ---
>   hw/ppc/pnv_lpc.c | 2 ++
>   1 file changed, 2 insertions(+)
>
> diff --git a/hw/ppc/pnv_lpc.c b/hw/ppc/pnv_lpc.c
> index 01f44c19eb..67fd049a7f 100644
> --- a/hw/ppc/pnv_lpc.c
> +++ b/hw/ppc/pnv_lpc.c
> @@ -738,6 +738,8 @@ static void pnv_lpc_realize(DeviceState *dev, Error **errp)
>                                   &lpc->opb_master_regs);
>       memory_region_init_io(&lpc->lpc_hc_regs, OBJECT(dev), &lpc_hc_ops, lpc,
>                             "lpc-hc", LPC_HC_REGS_OPB_SIZE);
> +    /* xscom writes to lpc-hc. As such mark lpc-hc re-entrancy safe */
> +    lpc->lpc_hc_regs.disable_reentrancy_guard = true;
>       memory_region_add_subregion(&lpc->opb_mr, LPC_HC_REGS_OPB_ADDR,
>                                   &lpc->lpc_hc_regs);
>   

The warning changed :

  qemu-system-ppc64: warning: Blocked re-entrant IO on MemoryRegion: 
lpc-opb-master at addr: 0x8

I will take a look unless you know exactly what to do.

Thanks,

C.