Re: [Qemu-devel] [PATCH v1 2/6] pvrdma: add uar_read routine

[Marcel Apfelbaum <marcel.apfelbaum@gmail.com>]

Hi Prasad,


On 12/12/18 1:47 PM, P J P wrote:
> From: Prasad J Pandit <pjp@fedoraproject.org>
>
> Define skeleton 'uar_read' routine. Avoid NULL dereference.
>
> Reported-by: Li Qiang <liq3ea@163.com>
> Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org>
> ---
>   hw/rdma/vmw/pvrdma_main.c | 6 ++++++
>   1 file changed, 6 insertions(+)
>
> diff --git a/hw/rdma/vmw/pvrdma_main.c b/hw/rdma/vmw/pvrdma_main.c
> index 23dc9926e3..8a03ab4669 100644
> --- a/hw/rdma/vmw/pvrdma_main.c
> +++ b/hw/rdma/vmw/pvrdma_main.c
> @@ -448,6 +448,11 @@ static const MemoryRegionOps regs_ops = {
>       },
>   };
>   
> +static uint64_t uar_read(void *opaque, hwaddr addr, unsigned size)
> +{
> +    return 0;

The PCI read operation should fail if the read op is  not implemented.
Please use  "return 0xffffffff" to emulate the PCI read failure.
(0 is a successfully read)

Thanks,
Marcel

> +}
> +
>   static void uar_write(void *opaque, hwaddr addr, uint64_t val, unsigned size)
>   {
>       PVRDMADev *dev = opaque;
> @@ -489,6 +494,7 @@ static void uar_write(void *opaque, hwaddr addr, uint64_t val, unsigned size)
>   }
>   
>   static const MemoryRegionOps uar_ops = {
> +    .read = uar_read,
>       .write = uar_write,
>       .endianness = DEVICE_LITTLE_ENDIAN,
>       .impl = {