Re: [PATCH-for-5.2] memory: Add trace events to audit MemoryRegionOps fields

[Paolo Bonzini]

On 06/08/20 17:26, Philippe Mathieu-Daudé wrote:
> Add trace events to audit MemoryRegionOps field such:
>  - are all the valid/impl fields provided?
>  - is the region a power of two?
> 
> These cases are accepted, but it is interesting to list them.
> 
> Example:
> 
>   $ qemu-system-i386 -S -trace memory_region_io_check\*
>   memory_region_io_check_odd_size mr name:'dma-page' size:0x3
>   memory_region_io_check_access_size_incomplete mr name:'acpi-tmr' 
> min/max:[valid:1/4 impl:4/0]
>   memory_region_io_check_access_size_incomplete mr name:'acpi-evt' 
> min/max:[valid:1/2 impl:2/0]
>   memory_region_io_check_access_size_incomplete mr name:'acpi-cnt' 
> min/max:[valid:1/2 impl:2/0]

Can they be detected using Coccinelle instead?

Paolo

> 
> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
> ---
> Based-on: <20200805130221.24487-1-philmd@redhat.com>
>           "softmmu: Add missing trace-events file"
> ---
>  softmmu/memory.c     | 11 +++++++++++
>  softmmu/trace-events |  2 ++
>  2 files changed, 13 insertions(+)
> 
> diff --git a/softmmu/memory.c b/softmmu/memory.c
> index d030eb6f7c..daa0daf2a8 100644
> --- a/softmmu/memory.c
> +++ b/softmmu/memory.c
> @@ -1488,6 +1488,17 @@ void memory_region_init_io(MemoryRegion *mr,
>      mr->ops = ops ? ops : &unassigned_mem_ops;
>      mr->opaque = opaque;
>      mr->terminates = true;
> +    if (size != UINT64_MAX && !is_power_of_2(size)) {
> +        trace_memory_region_io_check_odd_size(name, size);
> +    }
> +    if (ops && (!ops->impl.min_access_size || !ops->impl.max_access_size ||
> +                !ops->valid.min_access_size || !ops->valid.max_access_size)) 
> {
> +        trace_memory_region_io_check_access_size_incomplete(name,
> +                mr->ops->valid.min_access_size,
> +                mr->ops->valid.max_access_size,
> +                mr->ops->impl.min_access_size,
> +                mr->ops->impl.max_access_size);
> +    }
>  }
>  
>  void memory_region_init_ram_nomigrate(MemoryRegion *mr,
> diff --git a/softmmu/trace-events b/softmmu/trace-events
> index b80ca042e1..00eb316aef 100644
> --- a/softmmu/trace-events
> +++ b/softmmu/trace-events
> @@ -18,6 +18,8 @@ memory_region_ram_device_write(int cpu_index, void *mr, 
> uint64_t addr, uint64_t
>  flatview_new(void *view, void *root) "%p (root %p)"
>  flatview_destroy(void *view, void *root) "%p (root %p)"
>  flatview_destroy_rcu(void *view, void *root) "%p (root %p)"
> +memory_region_io_check_odd_size(const char *name, uint64_t size) "mr 
> name:'%s' size:0x%"PRIx64
> +memory_region_io_check_access_size_incomplete(const char *name, unsigned 
> vmin, unsigned vmax, unsigned imin, unsigned imax) "mr name:'%s' 
> min/max:[valid:%u/%u impl:%u/%u]"
>  
>  # vl.c
>  vm_state_notify(int running, int reason, const char *reason_str) "running %d 
> reason %d (%s)"
>