Re: [PATCH v3 3/3] hw/vfio: let read-only flag take effect for mmap'd regions

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

On 4/13/20 8:37 AM, Yan Zhao wrote:
> along side setting host page table to be read-only, the memory regions
> are also required to be read-only, so that when guest writes to the
> read-only & mmap'd regions, vmexits would happen and region write handlers
> are called.
> 
> Signed-off-by: Yan Zhao <yan.y.zhao@intel.com>
> Signed-off-by: Xin Zeng <xin.zeng@intel.com>
> ---
>   hw/vfio/common.c | 4 ++++
>   1 file changed, 4 insertions(+)
> 
> diff --git a/hw/vfio/common.c b/hw/vfio/common.c
> index fd6ee1fe3e..fc7618e041 100644
> --- a/hw/vfio/common.c
> +++ b/hw/vfio/common.c
> @@ -977,6 +977,10 @@ int vfio_region_mmap(VFIORegion *region)
>                                             name, region->mmaps[i].size,
>                                             region->mmaps[i].mmap);
>           g_free(name);
> +
> +        if (!(region->flags & VFIO_REGION_INFO_FLAG_WRITE)) {
> +            memory_region_set_readonly(&region->mmaps[i].mem, true);
> +        }
>           memory_region_add_subregion(region->mem, region->mmaps[i].offset,
>                                       &region->mmaps[i].mem);
>   
> 

Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>