Re: [PATCH 1/3] arm64: realm: ioremap: Allow mapping memory as encrypted

[Gavin Shan <gshan@redhat.com>]

On 6/13/25 9:11 PM, Suzuki K Poulose wrote:
> For ioremap(), so far we only checked if it was a device (RIPAS_DEV) to choose
> an encrypted vs decrypted mapping. However, we may have firmware reserved memory
> regions exposed to the OS (e.g., EFI Coco Secret Securityfs, ACPI CCEL).
> We need to make sure that anything that is RIPAS_RAM (i.e., Guest
> protected memory with RMM guarantees) are also mapped as encrypted.
> 
> Rephrasing the above, anything that is not RIPAS_EMPTY is guaranteed to be
> protected by the RMM. Thus we choose encrypted mapping for anything that is not
> RIPAS_EMPTY. While at it, rename the helper function
> 
>    __arm64_is_protected_mmio => arm64_rsi_is_protected
> 
> to clearly indicate that this not an arm64 generic helper, but something to do
> with Realms.
> 
> Cc: Sami Mujawar <sami.mujawar@arm.com>
> Cc: Will Deacon <will@kernel.org>
> Cc: Catalin Marinas <catalin.marinas@arm.com>
> Cc: "Aneesh Kumar K.V" <aneesh.kumar@kernel.org>
> Cc: Steven Price <steven.price@arm.com>
> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
> ---
>   arch/arm64/include/asm/io.h  |  2 +-
>   arch/arm64/include/asm/rsi.h |  2 +-
>   arch/arm64/kernel/rsi.c      | 26 ++++++++++++++++++++++----
>   3 files changed, 24 insertions(+), 6 deletions(-)
> 

Reviewed-by: Gavin Shan <gshan@redhat.com>