arm64: Don't trap host pointer auth use to EL2

To allow EL0 (and/or EL1) to use pointer authentication functionality,
we must ensure that pointer authentication instructions and accesses to
pointer authentication keys are not trapped to EL2.

This patch ensures that HCR_EL2 is configured appropriately when the
kernel is booted at EL2. For non-VHE kernels we set HCR_EL2.{API,APK},
ensuring that EL1 can access keys and permit EL0 use of instructions.
For VHE kernels host EL0 (TGE && E2H) is unaffected by these settings,
and it doesn't matter how we configure HCR_EL2.{API,APK}, so we don't
bother setting them.

This does not enable support for KVM guests, since KVM manages HCR_EL2
itself when running VMs.

Reviewed-by: Richard Henderson <[email protected]>
Signed-off-by: Mark Rutland <[email protected]>
Signed-off-by: Kristina Martsenko <[email protected]>
Acked-by: Christoffer Dall <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Marc Zyngier <[email protected]>
Cc: Will Deacon <[email protected]>
Cc: [email protected]
Signed-off-by: Will Deacon <[email protected]>

0 files changed, 0 insertions, 0 deletions