On Thu, Feb 15, 2018 at 10:02:56PM +0100, Christoffer Dall wrote: > VHE actually doesn't rely on clearing the VTTBR when returning to the > host kernel, and that is the current key mechanism of hyp_panic to > figure out how to attempt to return to a state good enough to print a > panic statement. > > Therefore, we split the hyp_panic function into two functions, a VHE and > a non-VHE, keeping the non-VHE version intact, but changing the VHE > behavior. > > The vttbr_el2 check on VHE doesn't really make that much sense, because > the only situation where we can get here on VHE is when the hypervisor > assembly code actually called into hyp_panic, which only happens when > VBAR_EL2 has been set to the KVM exception vectors. On VHE, we can > always safely disable the traps and restore the host registers at this > point, so we simply do that unconditionally and call into the panic > function directly. > > Acked-by: Marc Zyngier <marc.zyngier@xxxxxxx> > Signed-off-by: Christoffer Dall <christoffer.dall@xxxxxxxxxx> > --- > > Notes: > Changes since v1: > - Fixed typos in the commit message > - Still use the generic __deactivte_traps() function in the hyp panic > code until we rework that logic later. > > arch/arm64/kvm/hyp/switch.c | 42 +++++++++++++++++++++++------------------- > 1 file changed, 23 insertions(+), 19 deletions(-) > Reviewed-by: Andrew Jones <drjones@xxxxxxxxxx>
