diff options
| author | Vipin Sharma <vipinsh@google.com> | 2023-03-21 15:00:11 -0700 |
|---|---|---|
| committer | Sean Christopherson <seanjc@google.com> | 2023-04-04 12:37:30 -0700 |
| commit | 697c89bed94effde145d84e618142dd89b2b54af (patch) | |
| tree | 651b62af4618d6b9550a3b09ca70e0ed825f4c1a /arch/x86/kvm | |
| parent | 5982a5392663b30f57ee90b0372c19a7e9cb655a (diff) | |
KVM: x86/mmu: Consolidate Dirty vs. Writable clearing logic in TDP MMU
Deduplicate the guts of the TDP MMU's clearing of dirty status by
snapshotting whether to check+clear the Dirty bit vs. the Writable bit,
which is the only difference between the two flavors of dirty tracking.
Note, kvm_ad_enabled() is just a wrapper for shadow_accessed_mask, i.e.
is constant after kvm-{intel,amd}.ko is loaded.
Link: https://lore.kernel.org/all/Yz4Qi7cn7TWTWQjj@google.com
Signed-off-by: Vipin Sharma <vipinsh@google.com>
[sean: split to separate patch, apply to dirty log, write changelog]
Link: https://lore.kernel.org/r/20230321220021.2119033-4-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Diffstat (limited to 'arch/x86/kvm')
| -rw-r--r-- | arch/x86/kvm/mmu/tdp_mmu.c | 35 |
1 files changed, 9 insertions, 26 deletions
diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c index 5a5642650c3e..b32c9ba05c89 100644 --- a/arch/x86/kvm/mmu/tdp_mmu.c +++ b/arch/x86/kvm/mmu/tdp_mmu.c @@ -1607,8 +1607,8 @@ void kvm_tdp_mmu_try_split_huge_pages(struct kvm *kvm, static bool clear_dirty_gfn_range(struct kvm *kvm, struct kvm_mmu_page *root, gfn_t start, gfn_t end) { + u64 dbit = kvm_ad_enabled() ? shadow_dirty_mask : PT_WRITABLE_MASK; struct tdp_iter iter; - u64 new_spte; bool spte_set = false; rcu_read_lock(); @@ -1624,19 +1624,10 @@ retry: MMU_WARN_ON(kvm_ad_enabled() && spte_ad_need_write_protect(iter.old_spte)); - if (!kvm_ad_enabled()) { - if (is_writable_pte(iter.old_spte)) - new_spte = iter.old_spte & ~PT_WRITABLE_MASK; - else - continue; - } else { - if (iter.old_spte & shadow_dirty_mask) - new_spte = iter.old_spte & ~shadow_dirty_mask; - else - continue; - } + if (!(iter.old_spte & dbit)) + continue; - if (tdp_mmu_set_spte_atomic(kvm, &iter, new_spte)) + if (tdp_mmu_set_spte_atomic(kvm, &iter, iter.old_spte & ~dbit)) goto retry; spte_set = true; @@ -1678,8 +1669,9 @@ bool kvm_tdp_mmu_clear_dirty_slot(struct kvm *kvm, static void clear_dirty_pt_masked(struct kvm *kvm, struct kvm_mmu_page *root, gfn_t gfn, unsigned long mask, bool wrprot) { + u64 dbit = (wrprot || !kvm_ad_enabled()) ? PT_WRITABLE_MASK : + shadow_dirty_mask; struct tdp_iter iter; - u64 new_spte; rcu_read_lock(); @@ -1697,19 +1689,10 @@ static void clear_dirty_pt_masked(struct kvm *kvm, struct kvm_mmu_page *root, mask &= ~(1UL << (iter.gfn - gfn)); - if (wrprot || !kvm_ad_enabled()) { - if (is_writable_pte(iter.old_spte)) - new_spte = iter.old_spte & ~PT_WRITABLE_MASK; - else - continue; - } else { - if (iter.old_spte & shadow_dirty_mask) - new_spte = iter.old_spte & ~shadow_dirty_mask; - else - continue; - } + if (!(iter.old_spte & dbit)) + continue; - tdp_mmu_set_spte_no_dirty_log(kvm, &iter, new_spte); + tdp_mmu_set_spte_no_dirty_log(kvm, &iter, iter.old_spte & ~dbit); } rcu_read_unlock(); |