On Fri, Jun 18, 2021 at 1:58 AM Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
>
> On Fri, Jun 18, 2021 at 04:48:15AM +0000, Jing Zhang wrote:
> > Add a VM ioctl to get a statistics file descriptor by which a read
> > functionality is provided for userspace to read out VM stats header,
> > descriptors and data.
> > Define VM statistics descriptors and header for all architectures.
> >
> > Reviewed-by: David Matlack <dmatlack@xxxxxxxxxx>
> > Reviewed-by: Ricardo Koller <ricarkol@xxxxxxxxxx>
> > Reviewed-by: Krish Sadhukhan <krish.sadhukhan@xxxxxxxxxx>
> > Reviewed-by: Fuad Tabba <tabba@xxxxxxxxxx>
> > Tested-by: Fuad Tabba <tabba@xxxxxxxxxx> #arm64
> > Signed-off-by: Jing Zhang <jingzhangos@xxxxxxxxxx>
> > ---
> > arch/arm64/kvm/guest.c | 14 +++++++++++++
> > arch/mips/kvm/mips.c | 14 +++++++++++++
> > arch/powerpc/kvm/book3s.c | 16 +++++++++++++++
> > arch/powerpc/kvm/booke.c | 16 +++++++++++++++
> > arch/s390/kvm/kvm-s390.c | 19 +++++++++++++++++
> > arch/x86/kvm/x86.c | 24 ++++++++++++++++++++++
> > include/linux/kvm_host.h | 6 ++++++
> > virt/kvm/kvm_main.c | 43 +++++++++++++++++++++++++++++++++++++++
> > 8 files changed, 152 insertions(+)
> >
> > diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c
> > index 4962331d01e6..f456d1defe2b 100644
> > --- a/arch/arm64/kvm/guest.c
> > +++ b/arch/arm64/kvm/guest.c
> > @@ -28,6 +28,20 @@
> >
> > #include "trace.h"
> >
> > +struct _kvm_stats_desc kvm_vm_stats_desc[] = {
> > + KVM_GENERIC_VM_STATS()
> > +};
> > +static_assert(ARRAY_SIZE(kvm_vm_stats_desc) ==
> > + sizeof(struct kvm_vm_stat) / sizeof(u64));
> > +
> > +struct kvm_stats_header kvm_vm_stats_header = {
>
> Can this be const?
>
> > + .name_size = KVM_STATS_NAME_LEN,
> > + .count = ARRAY_SIZE(kvm_vm_stats_desc),
> > + .desc_offset = sizeof(struct kvm_stats_header) + KVM_STATS_ID_MAXLEN,
> > + .data_offset = sizeof(struct kvm_stats_header) + KVM_STATS_ID_MAXLEN +
> > + sizeof(kvm_vm_stats_desc),
> > +};
>
> If it can't be const, what is modified in it that prevents that from
> happening?
>
> thanks,
>
> greg k-h
Yes, it can be const.
Thanks,
Jing
