arm64: KVM: implement lazy world switch for debug registers

Implement switching of the debug registers. While the number
of registers is massive, CPUs usually don't implement them all
(A57 has 6 breakpoints and 4 watchpoints, which gives us a total
of 22 registers "only").

Also, we only save/restore them when MDSCR_EL1 has debug enabled,
or when we've flagged the debug registers as dirty. It means that
most of the time, we only save/restore MDSCR_EL1.

Reviewed-by: Anup Patel <[email protected]>
Reviewed-by: Christoffer Dall <[email protected]>
Signed-off-by: Marc Zyngier <[email protected]>

0 files changed, 0 insertions, 0 deletions