On 25/04/17 18:02, James Morse wrote:
> 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 <james.morse@xxxxxxx>
> ---
> arch/arm/kvm/hyp/switch.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/arch/arm/kvm/hyp/switch.c b/arch/arm/kvm/hyp/switch.c
> index 92678b7bd046..c8f15bb5c8b3 100644
> --- a/arch/arm/kvm/hyp/switch.c
> +++ b/arch/arm/kvm/hyp/switch.c
> @@ -235,8 +235,10 @@ void __hyp_text __noreturn __hyp_panic(int cause)
>
> 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);
> }
Reviewed-by: Marc Zyngier <marc.zyngier@xxxxxxx>
Thanks,
M.
--
Jazz is not dead. It just smells funny...
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