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| author | Ben Gardon <bgardon@google.com> | 2022-05-26 02:09:04 +0300 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2022-06-07 18:28:49 +0300 |
| commit | 5ba7c4c6d1c7af47a916f728bb5940669684a087 (patch) | |
| tree | 01a742d7f0caaa0f44d4564256bde24fa5c92aa7 /arch/x86/kvm/mmu/tdp_iter.h | |
| parent | 1df931d95f4dc1c11db1123e85d4e08156e46ef9 (diff) | |
| download | linux-5ba7c4c6d1c7af47a916f728bb5940669684a087.tar.xz | |
KVM: x86/MMU: Zap non-leaf SPTEs when disabling dirty logging
Currently disabling dirty logging with the TDP MMU is extremely slow.
On a 96 vCPU / 96G VM backed with gigabyte pages, it takes ~200 seconds
to disable dirty logging with the TDP MMU, as opposed to ~4 seconds with
the shadow MMU.
When disabling dirty logging, zap non-leaf parent entries to allow
replacement with huge pages instead of recursing and zapping all of the
child, leaf entries. This reduces the number of TLB flushes required.
and reduces the disable dirty log time with the TDP MMU to ~3 seconds.
Opportunistically add a WARN() to catch GFNs that are mapped at a
higher level than their max level.
Signed-off-by: Ben Gardon <bgardon@google.com>
Message-Id: <20220525230904.1584480-1-bgardon@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kvm/mmu/tdp_iter.h')
| -rw-r--r-- | arch/x86/kvm/mmu/tdp_iter.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/x86/kvm/mmu/tdp_iter.h b/arch/x86/kvm/mmu/tdp_iter.h index f0af385c56e0..adfca0cf94d3 100644 --- a/arch/x86/kvm/mmu/tdp_iter.h +++ b/arch/x86/kvm/mmu/tdp_iter.h @@ -114,5 +114,6 @@ void tdp_iter_start(struct tdp_iter *iter, struct kvm_mmu_page *root, int min_level, gfn_t next_last_level_gfn); void tdp_iter_next(struct tdp_iter *iter); void tdp_iter_restart(struct tdp_iter *iter); +void tdp_iter_step_up(struct tdp_iter *iter); #endif /* __KVM_X86_MMU_TDP_ITER_H */ |