On Mon, 19 Aug 2024 14:19:22 +0100,
Steven Price [off-list ref] wrote:

Within a realm guest the ITS is emulated by the host. This means the
allocations must have been made available to the host by a call to
set_memory_decrypted(). Introduce an allocation function which performs
this extra call.

For the ITT use a custom genpool-based allocator that calls
set_memory_decrypted() for each page allocated, but then suballocates
the size needed for each ITT. Note that there is no mechanism
implemented to return pages from the genpool, but it is unlikely the
peak number of devices will so much larger than the normal level - so
this isn't expected to be an issue.

Co-developed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Tested-by: Will Deacon <will@kernel.org>
Signed-off-by: Steven Price <steven.price@arm.com>
---
Changes since v3:
 * Use BIT() macro.
 * Use a genpool based allocator in its_create_device() to avoid
   allocating a full page.
 * Fix subject to drop "realm" and use gic-v3-its.
 * Add error handling to ITS alloc/free.
Changes since v2:
 * Drop 'shared' from the new its_xxx function names as they are used
   for non-realm guests too.
 * Don't handle the NUMA_NO_NODE case specially - alloc_pages_node()
   should do the right thing.
 * Drop a pointless (void *) cast.
---
 drivers/irqchip/irq-gic-v3-its.c | 139 ++++++++++++++++++++++++++-----
 1 file changed, 116 insertions(+), 23 deletions(-)

I think this patch and the next are pretty ripe, and shouldn't have to
wait much longer.

Can you please send them as a separate irqchip series, with the
relevant people on Cc (realistically, tglx and me), with a

Reviewed-by: Marc Zyngier <maz@kernel.org>

added to them?

Thanks,

	M.

-- 
Without deviation from the norm, progress is not possible.