Re: [PATCH v3 3/9] vfio: add quirk device write method

[Peter Maydell <peter.maydell@linaro.org>]

On Tue, 30 Jun 2020 at 13:30, P J P <ppandit@redhat.com> wrote:
>
> From: Prasad J Pandit <pjp@fedoraproject.org>
>
> Add vfio quirk device mmio write method to avoid NULL pointer
> dereference issue.
>
> Reported-by: Lei Sun <slei.casper@gmail.com>
> Reviewed-by: Li Qiang <liq3ea@gmail.com>
> Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org>
> ---
>  hw/vfio/pci-quirks.c | 8 ++++++++
>  1 file changed, 8 insertions(+)
>
> Update v3: Add Reviewed-by: ...
>   -> https://lists.gnu.org/archive/html/qemu-devel/2020-06/msg09406.html
>
> diff --git a/hw/vfio/pci-quirks.c b/hw/vfio/pci-quirks.c
> index d304c81148..cc6d5dbc23 100644
> --- a/hw/vfio/pci-quirks.c
> +++ b/hw/vfio/pci-quirks.c
> @@ -14,6 +14,7 @@
>  #include "config-devices.h"
>  #include "exec/memop.h"
>  #include "qemu/units.h"
> +#include "qemu/log.h"
>  #include "qemu/error-report.h"
>  #include "qemu/main-loop.h"
>  #include "qemu/module.h"
> @@ -264,8 +265,15 @@ static uint64_t vfio_ati_3c3_quirk_read(void *opaque,
>      return data;
>  }
>
> +static void vfio_ati_3c3_quirk_write(void *opaque, hwaddr addr,
> +                                        uint64_t data, unsigned size)
> +{
> +    qemu_log_mask(LOG_GUEST_ERROR, "%s not implemented\n", __func__);
> +}
> +
>  static const MemoryRegionOps vfio_ati_3c3_quirk = {
>      .read = vfio_ati_3c3_quirk_read,
> +    .write = vfio_ati_3c3_quirk_write,
>      .endianness = DEVICE_LITTLE_ENDIAN,
>  };


Alex (Williamson) -- as the vfio maintainer, do you have a view
on whether we should be logging write accesses to port 0x3c3
here as guest-errors or unimplemented-QEMU-functionality?

Guest-error seems plausible to me, anyway.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>

thanks
-- PMM