Re: [PATCH] hw/cxl/cxl-host: Fix guest crash when getting cxl-fmw property

[Zhijian Li (Fujitsu)]

On 04/07/2024 17:34, Zhao Liu wrote:
> From: Zhao Liu <zhao1.liu@intel.com>
> 
> Guest crashes (Segmentation fault) when getting cxl-fmw property via
> qmp:
> 

IMO, it's fair to say "Guest crashes" which generally means the guest kernel 
panic etc.
I'd prefer the subject like:
hw/cxl/cxl-host: Fix segmentation fault when getting cxl-fmw property


Otherwise,

Reviewed-by: Li Zhijian <lizhijian@fujitsu.com>


> (QEMU) qom-get path=machine property=cxl-fmw
> 
> This issue is caused by accessing wrong callback (opaque) type in
> machine_get_cfmw().
> 
> cxl_machine_init() sets the callback as `CXLState *` type but
> machine_get_cfmw() treats the callback as
> `CXLFixedMemoryWindowOptionsList **`.
> 
> Fix this error by casting opaque to `CXLState *` type in
> machine_get_cfmw().
> 
> Fixes: 03b39fcf64bc ("hw/cxl: Make the CXL fixed memory window setup a 
> machine parameter.")
> Signed-off-by: Zhao Liu <zhao1.liu@intel.com>
> ---
>   hw/cxl/cxl-host.c | 3 ++-
>   1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/hw/cxl/cxl-host.c b/hw/cxl/cxl-host.c
> index c5f5fcfd64d0..e9f2543c43c6 100644
> --- a/hw/cxl/cxl-host.c
> +++ b/hw/cxl/cxl-host.c
> @@ -315,7 +315,8 @@ static void machine_set_cxl(Object *obj, Visitor *v, 
> const char *name,
>   static void machine_get_cfmw(Object *obj, Visitor *v, const char *name,
>                                void *opaque, Error **errp)
>   {
> -    CXLFixedMemoryWindowOptionsList **list = opaque;
> +    CXLState *state = opaque;
> +    CXLFixedMemoryWindowOptionsList **list = &state->cfmw_list;
>   
>       visit_type_CXLFixedMemoryWindowOptionsList(v, name, list, errp);
>   }