4.9-stable review patch. If anyone has any objections, please let me know.
------------------ From: James Morse <[email protected]> [ Upstream commit d2e19368848ce6065daa785efca26faed54732b6 ] When KVM panics, it hurridly restores the host context and parachutes into the host's panic() code. This looks like it was copied from arm64, the 32bit KVM panic code needs to restore the host's banked registers too. At some point panic() touches the physical timer/counter, this will trap back to HYP. If we're lucky, we panic again. Add a __timer_save_state() call to KVMs hyp_panic() path, this saves the guest registers and disables the traps for the host. Fixes: c36b6db5f3e4 ("ARM: KVM: Add panic handling code") Signed-off-by: James Morse <[email protected]> Reviewed-by: Marc Zyngier <[email protected]> Reviewed-by: Christoffer Dall <[email protected]> Signed-off-by: Christoffer Dall <[email protected]> Signed-off-by: Sasha Levin <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- arch/arm/kvm/hyp/switch.c | 2 ++ 1 file changed, 2 insertions(+) --- a/arch/arm/kvm/hyp/switch.c +++ b/arch/arm/kvm/hyp/switch.c @@ -237,8 +237,10 @@ void __hyp_text __noreturn __hyp_panic(i vcpu = (struct kvm_vcpu *)read_sysreg(HTPIDR); host_ctxt = kern_hyp_va(vcpu->arch.host_cpu_context); + __timer_save_state(vcpu); __deactivate_traps(vcpu); __deactivate_vm(vcpu); + __banked_restore_state(host_ctxt); __sysreg_restore_state(host_ctxt); }
