On 4/26/22, Mike Rapoport <rppt@xxxxxxxxxx> wrote:
> On Mon, Apr 25, 2022 at 02:15:19PM -0300, Martin Fernandez wrote:
>> Add the capability to mark regions of the memory memory_type able of
>> hardware memory encryption.
>>
>> Also add the capability to query if all regions of a memory node are
>> able to do hardware memory encryption to call it when initializing the
>> nodes. Warn the user if a node has both encryptable and
>> non-encryptable regions.
>>
>> Signed-off-by: Martin Fernandez <martin.fernandez@xxxxxxxxxxxxx>
>> ---
>> include/linux/memblock.h | 5 ++++
>> mm/memblock.c | 62 ++++++++++++++++++++++++++++++++++++++++
>> 2 files changed, 67 insertions(+)
>>
>> diff --git a/include/linux/memblock.h b/include/linux/memblock.h
>> index 50ad19662a32..00c4f1a20335 100644
>> --- a/include/linux/memblock.h
>> +++ b/include/linux/memblock.h
>> @@ -40,6 +40,7 @@ extern unsigned long long max_possible_pfn;
>> * via a driver, and never indicated in the firmware-provided memory map
>> as
>> * system RAM. This corresponds to IORESOURCE_SYSRAM_DRIVER_MANAGED in
>> the
>> * kernel resource tree.
>> + * @MEMBLOCK_CRYPTO_CAPABLE: capable of hardware encryption
>> */
>> enum memblock_flags {
>> MEMBLOCK_NONE = 0x0, /* No special request */
>> @@ -47,6 +48,7 @@ enum memblock_flags {
>> MEMBLOCK_MIRROR = 0x2, /* mirrored region */
>> MEMBLOCK_NOMAP = 0x4, /* don't add to kernel direct mapping */
>> MEMBLOCK_DRIVER_MANAGED = 0x8, /* always detected via a driver */
>> + MEMBLOCK_CRYPTO_CAPABLE = 0x10, /* capable of hardware encryption */
>> };
>>
>> /**
>> @@ -120,6 +122,9 @@ int memblock_physmem_add(phys_addr_t base, phys_addr_t
>> size);
>> void memblock_trim_memory(phys_addr_t align);
>> bool memblock_overlaps_region(struct memblock_type *type,
>> phys_addr_t base, phys_addr_t size);
>> +bool memblock_node_is_crypto_capable(int nid);
>> +int memblock_mark_crypto_capable(phys_addr_t base, phys_addr_t size);
>> +int memblock_clear_crypto_capable(phys_addr_t base, phys_addr_t size);
>> int memblock_mark_hotplug(phys_addr_t base, phys_addr_t size);
>> int memblock_clear_hotplug(phys_addr_t base, phys_addr_t size);
>> int memblock_mark_mirror(phys_addr_t base, phys_addr_t size);
>> diff --git a/mm/memblock.c b/mm/memblock.c
>> index e4f03a6e8e56..fe62f81572e6 100644
>> --- a/mm/memblock.c
>> +++ b/mm/memblock.c
>> @@ -191,6 +191,40 @@ bool __init_memblock memblock_overlaps_region(struct
>> memblock_type *type,
>> return i < type->cnt;
>> }
>>
>> +/**
>> + * memblock_node_is_crypto_capable - get if whole node is capable
>> + * of encryption
>> + * @nid: number of node
>> + *
>> + * Iterate over all memory memblock_type and find if all regions under
>> + * node @nid are capable of hardware encryption.
>> + *
>> + * Return:
>> + * true if every region in memory memblock_type is capable of
>
> I'd s/in memory memblock_type/in @nid
>
Good, thanks.
>> + * encryption, false otherwise.
>> + */
>> +bool __init_memblock memblock_node_is_crypto_capable(int nid)
>> +{
>> + struct memblock_region *region;
>> + int crypto_capables = 0;
>> + int not_crypto_capables = 0;
>> +
>> + for_each_mem_region(region) {
>> + if (memblock_get_region_node(region) == nid) {
>> + if (region->flags & MEMBLOCK_CRYPTO_CAPABLE)
>> + crypto_capables++;
>> + else
>> + not_crypto_capables++;
>> + }
>> + }
>> +
>> + if (crypto_capables > 0 && not_crypto_capables > 0)
>> + pr_warn("Node %d has %d regions that are encryptable and %d regions
>> that aren't",
>> + nid, not_crypto_capables, crypto_capables);
>> +
>> + return not_crypto_capables == 0;
>
> This will return true for memoryless nodes as well. Do you mean to consider
> them as capable of encryption?
>
Not really, I didn't think about that to be honest. I don't think it's
a good idea to consider them as capable, right?
