Re: [PATCH v3 5/8] KVM: x86/mmu: Add a field to control memslot rmap allocation

[David Hildenbrand]

On 07.05.21 01:44, Ben Gardon wrote:
> On Thu, May 6, 2021 at 11:43 AM Ben Gardon <bgardon@xxxxxxxxxx> wrote:
> > Add a field to control whether new memslots should have rmaps allocated
> > for them. As of this change, it's not safe to skip allocating rmaps, so
> > the field is always set to allocate rmaps. Future changes will make it
> > safe to operate without rmaps, using the TDP MMU. Then further changes
> > will allow the rmaps to be allocated lazily when needed for nested
> > oprtation.
> >
> > No functional change expected.
> >
> > Signed-off-by: Ben Gardon <bgardon@xxxxxxxxxx>
> > ---
> >   arch/x86/include/asm/kvm_host.h |  8 ++++++++
> >   arch/x86/kvm/mmu/mmu.c          |  2 ++
> >   arch/x86/kvm/x86.c              | 18 +++++++++++++-----
> >   3 files changed, 23 insertions(+), 5 deletions(-)
> >
> > diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
> > index ad22d4839bcc..00065f9bbc5e 100644
> > --- a/arch/x86/include/asm/kvm_host.h
> > +++ b/arch/x86/include/asm/kvm_host.h
> > @@ -1122,6 +1122,12 @@ struct kvm_arch {
> >           */
> >          spinlock_t tdp_mmu_pages_lock;
> >   #endif /* CONFIG_X86_64 */
> > +
> > +       /*
> > +        * If set, rmaps have been allocated for all memslots and should be
> > +        * allocated for any newly created or modified memslots.
> > +        */
> > +       bool memslots_have_rmaps;
> >   };
> >
> >   struct kvm_vm_stat {
> > @@ -1853,4 +1859,6 @@ static inline int kvm_cpu_get_apicid(int mps_cpu)
> >
> >   int kvm_cpu_dirty_log_size(void);
> >
> > +inline bool kvm_memslots_have_rmaps(struct kvm *kvm);
>
> Woops, this shouldn't be marked inline as it creates build problems
> for the next patch with some configs.

With that fixed

Reviewed-by: David Hildenbrand <david@xxxxxxxxxx>


--
Thanks,

David / dhildenb