Re: [PATCH V2 1/2] efi/unaccepted: Do not let /proc/vmcore try to access unaccepted memory

[David Hildenbrand <david@redhat.com>]

On 11.09.23 13:21, Adrian Hunter wrote:
> Support for unaccepted memory was added recently, refer commit dcdfdd40fa82
> ("mm: Add support for unaccepted memory"), whereby a virtual machine may
> need to accept memory before it can be used.
> 
> Do not let /proc/vmcore try to access unaccepted memory because it can
> cause the guest to fail.
> 
> For /proc/vmcore, which is read-only, this means a read or mmap of
> unaccepted memory will return zeros.
> 
> Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
> ---

[...]

> +static inline bool pfn_is_unaccepted_memory(unsigned long pfn)
> +{
> +	phys_addr_t paddr = pfn << PAGE_SHIFT;
> +
> +	return range_contains_unaccepted_memory(paddr, paddr + PAGE_SIZE);
> +}
> +
>   #endif /* _LINUX_MM_H */

As stated, if the relevant table is not already properly populated with 
information about unaccepted memory by the first kernel, this probably 
logically belongs into Kirills series.

Reviewed-by: David Hildenbrand <david@redhat.com>

-- 
Cheers,

David / dhildenb