Re: [PATCH 4/6] prep: add ppc-parity write method

["Philippe Mathieu-Daudé" <philmd@redhat.com>]

On 6/17/20 7:39 AM, P J P wrote:
> From: Prasad J Pandit <pjp@fedoraproject.org>
> 
> Add ppc-parity mmio write method to avoid NULL pointer dereference
> issue.
> 
> Reported-by: Lei Sun <slei.casper@gmail.com>
> Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org>
> ---
>  hw/ppc/prep_systemio.c | 8 ++++++++
>  1 file changed, 8 insertions(+)
> 
> diff --git a/hw/ppc/prep_systemio.c b/hw/ppc/prep_systemio.c
> index bbc51b6e9a..aacd7831fd 100644
> --- a/hw/ppc/prep_systemio.c
> +++ b/hw/ppc/prep_systemio.c
> @@ -23,6 +23,7 @@
>   */
>  
>  #include "qemu/osdep.h"
> +#include "qemu/log.h"
>  #include "hw/irq.h"
>  #include "hw/isa/isa.h"
>  #include "hw/qdev-properties.h"
> @@ -235,8 +236,15 @@ static uint64_t ppc_parity_error_readl(void *opaque, hwaddr addr,
>      return val;
>  }
>  
> +static void ppc_parity_error_writel(void *opaque, hwaddr addr,
> +                                    uint64_t data, unsigned size)
> +{
> +    qemu_log_mask(LOG_UNIMP, "%s not implemented\n", __func__);

I understand the parity bits are calculated by the hardware, I doubt we
can write them. So probably LOG_GUEST_ERROR or a transaction failure here.

> +}
> +
>  static const MemoryRegionOps ppc_parity_error_ops = {
>      .read = ppc_parity_error_readl,
> +    .write = ppc_parity_error_writel,
>      .valid = {
>          .min_access_size = 4,
>          .max_access_size = 4,
>