From a1419f8b5bab477d96a71d1c37da0784fb18dc51 Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Fri, 12 Feb 2021 16:50:14 -0800 Subject: [PATCH] KVM: x86: Fold "write-protect large" use case into generic write-protect Drop kvm_mmu_slot_largepage_remove_write_access() and refactor its sole caller to use kvm_mmu_slot_remove_write_access(). Remove the now-unused slot_handle_large_level() and slot_handle_all_level() helpers. No functional change intended. Signed-off-by: Sean Christopherson Message-Id: <20210213005015.1651772-14-seanjc@google.com> Signed-off-by: Paolo Bonzini --- arch/x86/kvm/mmu/mmu.c | 32 -------------------------------- arch/x86/kvm/x86.c | 32 +++++++++++++++++--------------- 2 files changed, 17 insertions(+), 47 deletions(-) diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index 562bff7..e2178e0 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -5205,22 +5205,6 @@ slot_handle_level(struct kvm *kvm, struct kvm_memory_slot *memslot, } static __always_inline bool -slot_handle_all_level(struct kvm *kvm, struct kvm_memory_slot *memslot, - slot_level_handler fn, bool lock_flush_tlb) -{ - return slot_handle_level(kvm, memslot, fn, PG_LEVEL_4K, - KVM_MAX_HUGEPAGE_LEVEL, lock_flush_tlb); -} - -static __always_inline bool -slot_handle_large_level(struct kvm *kvm, struct kvm_memory_slot *memslot, - slot_level_handler fn, bool lock_flush_tlb) -{ - return slot_handle_level(kvm, memslot, fn, PG_LEVEL_4K + 1, - KVM_MAX_HUGEPAGE_LEVEL, lock_flush_tlb); -} - -static __always_inline bool slot_handle_leaf(struct kvm *kvm, struct kvm_memory_slot *memslot, slot_level_handler fn, bool lock_flush_tlb) { @@ -5584,22 +5568,6 @@ void kvm_mmu_slot_leaf_clear_dirty(struct kvm *kvm, kvm_arch_flush_remote_tlbs_memslot(kvm, memslot); } -void kvm_mmu_slot_largepage_remove_write_access(struct kvm *kvm, - struct kvm_memory_slot *memslot) -{ - bool flush; - - write_lock(&kvm->mmu_lock); - flush = slot_handle_large_level(kvm, memslot, slot_rmap_write_protect, - false); - if (is_tdp_mmu_enabled(kvm)) - flush |= kvm_tdp_mmu_wrprot_slot(kvm, memslot, PG_LEVEL_2M); - write_unlock(&kvm->mmu_lock); - - if (flush) - kvm_arch_flush_remote_tlbs_memslot(kvm, memslot); -} - void kvm_mmu_zap_all(struct kvm *kvm) { struct kvm_mmu_page *sp, *node; diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index dca2c33..1d2bc89 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -10829,25 +10829,26 @@ static void kvm_mmu_slot_apply_flags(struct kvm *kvm, */ kvm_mmu_zap_collapsible_sptes(kvm, new); } else { - /* - * Large sptes are write-protected so they can be split on first - * write. New large sptes cannot be created for this slot until - * the end of the logging. See the comments in fast_page_fault(). - * - * For small sptes, nothing is done if the dirty log is in the - * initial-all-set state. Otherwise, depending on whether pml - * is enabled the D-bit or the W-bit will be cleared. - */ + /* By default, write-protect everything to log writes. */ + int level = PG_LEVEL_4K; + if (kvm_x86_ops.cpu_dirty_log_size) { + /* + * Clear all dirty bits, unless pages are treated as + * dirty from the get-go. + */ if (!kvm_dirty_log_manual_protect_and_init_set(kvm)) kvm_mmu_slot_leaf_clear_dirty(kvm, new); - kvm_mmu_slot_largepage_remove_write_access(kvm, new); - } else { - int level = - kvm_dirty_log_manual_protect_and_init_set(kvm) ? - PG_LEVEL_2M : PG_LEVEL_4K; /* + * Write-protect large pages on write so that dirty + * logging happens at 4k granularity. No need to + * write-protect small SPTEs since write accesses are + * logged by the CPU via dirty bits. + */ + level = PG_LEVEL_2M; + } else if (kvm_dirty_log_manual_protect_and_init_set(kvm)) { + /* * If we're with initial-all-set, we don't need * to write protect any small page because * they're reported as dirty already. However @@ -10855,8 +10856,9 @@ static void kvm_mmu_slot_apply_flags(struct kvm *kvm, * so that the page split can happen lazily on * the first write to the huge page. */ - kvm_mmu_slot_remove_write_access(kvm, new, level); + level = PG_LEVEL_2M; } + kvm_mmu_slot_remove_write_access(kvm, new, level); } } -- 2.7.4