Re: [PATCH v5 1/5] mm/memblock: Tag memblocks with crypto capabilities

From: Martin Fernandez
Date: Fri Jan 14 2022 - 07:20:54 EST


On 1/14/22, Mike Rapoport <rppt@xxxxxxxxxx> wrote:
> On Thu, Jan 13, 2022 at 06:30:23PM -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.
>>
>> Signed-off-by: Martin Fernandez <martin.fernandez@xxxxxxxxxxxxx>
>> ---
>> include/linux/memblock.h | 5 ++++
>> mm/memblock.c | 49 ++++++++++++++++++++++++++++++++++++++++
>> 2 files changed, 54 insertions(+)
>>
>> diff --git a/include/linux/memblock.h b/include/linux/memblock.h
>> index 9dc7cb239d21..374c03e10b2e 100644
>> --- a/include/linux/memblock.h
>> +++ b/include/linux/memblock.h
>> @@ -41,6 +41,7 @@ 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 */
>> @@ -48,6 +49,7 @@ 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 */
>
> Nit: please keep the comments aligned with TAB.
>
>> };
>>
>> /**
>> @@ -121,6 +123,9 @@ 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 1018e50566f3..61ec50647469 100644
>> --- a/mm/memblock.c
>> +++ b/mm/memblock.c
>> @@ -191,6 +191,27 @@ 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.
>
> Please add Return: description, otherwise kernel-doc is unhappy
>
>> + */
>> +bool __init_memblock memblock_node_is_crypto_capable(int nid)
>> +{
>> + struct memblock_region *region;
>> +
>> + for_each_mem_region(region) {
>> + if ((memblock_get_region_node(region) == nid) &&
>> + !(region->flags & MEMBLOCK_CRYPTO_CAPABLE))
>> + return false;
>> + }
>
> As we discussed on v3, please add a printk if the same node has both
> crypto-capable and not crypto-capable regions.
>
> https://lore.kernel.org/all/Ya++1FwWzKr2wYQH@xxxxxxxxxx/
>
>> +
>> + return true;
>> +}
>> +
>> /**
>> * __memblock_find_range_bottom_up - find free area utility in bottom-up
>> * @start: start of candidate range
>> @@ -885,6 +906,34 @@ static int __init_memblock
>> memblock_setclr_flag(phys_addr_t base,
>> return 0;
>> }
>>
>> +/**
>> + * memblock_mark_crypto_capable - Mark memory regions capable of
>> hardware
>> + * encryption with flag MEMBLOCK_CRYPTO_CAPABLE.
>> + * @base: the base phys addr of the region
>> + * @size: the size of the region
>> + *
>> + * Return: 0 on success, -errno on failure.
>> + */
>> +int __init_memblock memblock_mark_crypto_capable(phys_addr_t base,
>> + phys_addr_t size)
>> +{
>> + return memblock_setclr_flag(base, size, 1, MEMBLOCK_CRYPTO_CAPABLE);
>> +}
>> +
>> +/**
>> + * memblock_clear_crypto_capable - Clear flag MEMBLOCK_CRYPTO for a
>> + * specified region.
>> + * @base: the base phys addr of the region
>> + * @size: the size of the region
>> + *
>> + * Return: 0 on success, -errno on failure.
>> + */
>> +int __init_memblock memblock_clear_crypto_capable(phys_addr_t base,
>> + phys_addr_t size)
>> +{
>> + return memblock_setclr_flag(base, size, 0, MEMBLOCK_CRYPTO_CAPABLE);
>> +}
>> +
>> /**
>> * memblock_mark_hotplug - Mark hotpluggable memory with flag
>> MEMBLOCK_HOTPLUG.
>> * @base: the base phys addr of the region
>> --
>> 2.30.2
>>
>
> --
> Sincerely yours,
> Mike.
>

Ok, will do. Thanks for the feedback.