On Thu, Feb 15, 2018 at 10:03:14PM +0100, Christoffer Dall wrote:

On non-VHE systems we need to save the ELR_EL2 and SPSR_EL2 so that we can
return to the host in EL1 in the same state and location where we issued a
hypercall to EL2, but on VHE ELR_EL2 and SPSR_EL2 are not useful because we
never enter a guest as a result of an exception entry that would be directly
handled by KVM. The kernel entry code already saves ELR_EL1/SPSR_EL1 on
exception entry, which is enough.  Therefore, factor out these registers into
separate save/restore functions, making it easy to exclude them from the VHE
world-switch path later on.

Reviewed-by: Marc Zyngier <redacted>
Signed-off-by: Christoffer Dall <redacted>
---
 arch/arm64/kvm/hyp/sysreg-sr.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

Reviewed-by: Andrew Jones <redacted>