On Mon, Aug 02, 2021, Paolo Bonzini wrote:

On 31/07/21 00:04, Peter Xu wrote:

quoted

Use this file to dump rmap statistic information.  The statistic is done by
calculating the rmap count and the result is log-2-based.

An example output of this looks like (idle 6GB guest, right after boot linux):

Rmap_Count:     0       1       2-3     4-7     8-15    16-31   32-63   64-127  128-255 256-511 512-1023
Level=4K:       3086676 53045   12330   1272    502     121     76      2       0       0       0
Level=2M:       5947    231     0       0       0       0       0       0       0       0       0
Level=1G:       32      0       0       0       0       0       0       0       0       0       0

Signed-off-by: Peter Xu <peterx@redhat.com>
---
  arch/x86/kvm/x86.c | 113 +++++++++++++++++++++++++++++++++++++++++++++
  1 file changed, 113 insertions(+)

This should be in debugfs.c, meaning that the kvm_mmu_slot_lpages() must be
in a header.  I think mmu.h should do, let me take a look and I can post
myself a v4 of these debugfs parts.

When you do post v4, don't forget to include both mmu.h and mmu/mmu_internal.h. :-)
kvm/queue is still broken...

arch/x86/kvm/debugfs.c: In function ‘kvm_mmu_rmaps_stat_show’:
arch/x86/kvm/debugfs.c:115:18: error: implicit declaration of function ‘kvm_mmu_slot_lpages’;
  115 |     lpage_size = kvm_mmu_slot_lpages(slot, k + 1);
      |                  ^~~~~~~~~~~~~~~~~~~
      |                  kvm_mmu_gfn_allow_lpage