Re: [PATCH v7 03/45] arm64: RME: Handle Granule Protection Faults (GPFs)

Gavin Shan
2025-03-02T23:44:04Z

On 2/14/25 2:13 AM, Steven Price wrote:
> If the host attempts to access granules that have been delegated for use
> in a realm these accesses will be caught and will trigger a Granule
> Protection Fault (GPF).
>
> A fault during a page walk signals a bug in the kernel and is handled by
> oopsing the kernel. A non-page walk fault could be caused by user space
> having access to a page which has been delegated to the kernel and will
> trigger a SIGBUS to allow debugging why user space is trying to access a
> delegated page.
>
> Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
> Signed-off-by: Steven Price <steven.price@arm.com>
> ---
> Changes since v2:
> * Include missing "Granule Protection Fault at level -1"
> ---
> arch/arm64/mm/fault.c | 31 +++++++++++++++++++++++++------
> 1 file changed, 25 insertions(+), 6 deletions(-)
>

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