On Tue, Apr 26, 2022 at 09:59:04AM -0300, Martin Fernandez wrote:
> 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?
I think capable of encryption would mean
crypto_capables && !not_crypto_capables
--
Sincerely yours,
Mike.
