Re: [PATCH kernel] KVM: PPC: Avoid lockdep debugging in TCE realmode handlers

[Paul Mackerras <paulus@ozlabs.org>]

On Fri, Mar 29, 2019 at 04:42:20PM +1100, Alexey Kardashevskiy wrote:
> The kvmppc_tce_to_ua() helper is called from real and virtual modes
> and it works fine as long as CONFIG_DEBUG_LOCKDEP is not enabled.
> However if the lockdep debugging is on, the lockdep will most likely break
> in kvm_memslots() because of srcu_dereference_check() so we need to use
> PPC-own kvm_memslots_raw() which uses realmode safe
> rcu_dereference_raw_notrace().
> 
> This creates a realmode copy of kvmppc_tce_to_ua() which replaces
> kvm_memslots() with kvm_memslots_raw().
> 
> Since kvmppc_rm_tce_to_ua() becomes static and can only be used inside
> HV KVM, this moves it earlier under CONFIG_KVM_BOOK3S_HV_POSSIBLE.
> 
> This moves truly virtual-mode kvmppc_tce_to_ua() to where it belongs and
> drops the prmap parameter which was never used in the virtual mode.
> 
> Fixes: d3695aa4f452 ("KVM: PPC: Add support for multiple-TCE hcalls", 2016-02-15)
> Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>

Thanks, patch applied to my kvm-ppc-next tree.

Paul.