Re: [PATCH v4 20/21] mm: add mmap_action_map_kernel_pages[_full]()

On 3/20/26 23:39, Lorenzo Stoakes (Oracle) wrote:
> A user can invoke mmap_action_map_kernel_pages() to specify that the
> mapping should map kernel pages starting from desc->start of a specified
> number of pages specified in an array.
> 
> In order to implement this, adjust mmap_action_prepare() to be able to
> return an error code, as it makes sense to assert that the specified
> parameters are valid as quickly as possible as well as updating the VMA
> flags to include VMA_MIXEDMAP_BIT as necessary.
> 
> This provides an mmap_prepare equivalent of vm_insert_pages().  We
> additionally update the existing vm_insert_pages() code to use
> range_in_vma() and add a new range_in_vma_desc() helper function for the
> mmap_prepare case, sharing the code between the two in range_is_subset().
> 
> We add both mmap_action_map_kernel_pages() and
> mmap_action_map_kernel_pages_full() to allow for both partial and full VMA
> mappings.
> 
> We update the documentation to reflect the new features.
> 
> Finally, we update the VMA tests accordingly to reflect the changes.
> 
> Reviewed-by: Suren Baghdasaryan <[email protected]>
> Signed-off-by: Lorenzo Stoakes (Oracle) <[email protected]>

Acked-by: Vlastimil Babka (SUSE) <[email protected]>