diff options
| -rw-r--r-- | arch/x86/include/asm/kvm_host.h | 2 | ||||
| -rw-r--r-- | arch/x86/kvm/mmu/mmu.c | 45 | ||||
| -rw-r--r-- | arch/x86/kvm/mmu/tdp_mmu.c | 54 | ||||
| -rw-r--r-- | arch/x86/kvm/mmu/tdp_mmu.h | 1 | ||||
| -rw-r--r-- | arch/x86/kvm/x86.c | 87 |
5 files changed, 36 insertions, 153 deletions
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index ffcfa84c969d..c15d6de8c457 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -1421,8 +1421,6 @@ void kvm_mmu_slot_leaf_clear_dirty(struct kvm *kvm, struct kvm_memory_slot *memslot); void kvm_mmu_slot_largepage_remove_write_access(struct kvm *kvm, struct kvm_memory_slot *memslot); -void kvm_mmu_slot_set_dirty(struct kvm *kvm, - struct kvm_memory_slot *memslot); void kvm_mmu_zap_all(struct kvm *kvm); void kvm_mmu_invalidate_mmio_sptes(struct kvm *kvm, u64 gen); unsigned long kvm_mmu_calculate_default_mmu_pages(struct kvm *kvm); diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index f208697781fc..562bff762c83 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -1181,36 +1181,6 @@ static bool __rmap_clear_dirty(struct kvm *kvm, struct kvm_rmap_head *rmap_head, return flush; } -static bool spte_set_dirty(u64 *sptep) -{ - u64 spte = *sptep; - - rmap_printk("spte %p %llx\n", sptep, *sptep); - - /* - * Similar to the !kvm_x86_ops.slot_disable_log_dirty case, - * do not bother adding back write access to pages marked - * SPTE_AD_WRPROT_ONLY_MASK. - */ - spte |= shadow_dirty_mask; - - return mmu_spte_update(sptep, spte); -} - -static bool __rmap_set_dirty(struct kvm *kvm, struct kvm_rmap_head *rmap_head, - struct kvm_memory_slot *slot) -{ - u64 *sptep; - struct rmap_iterator iter; - bool flush = false; - - for_each_rmap_spte(rmap_head, &iter, sptep) - if (spte_ad_enabled(*sptep)) - flush |= spte_set_dirty(sptep); - - return flush; -} - /** * kvm_mmu_write_protect_pt_masked - write protect selected PT level pages * @kvm: kvm instance @@ -5630,21 +5600,6 @@ void kvm_mmu_slot_largepage_remove_write_access(struct kvm *kvm, kvm_arch_flush_remote_tlbs_memslot(kvm, memslot); } -void kvm_mmu_slot_set_dirty(struct kvm *kvm, - struct kvm_memory_slot *memslot) -{ - bool flush; - - write_lock(&kvm->mmu_lock); - flush = slot_handle_all_level(kvm, memslot, __rmap_set_dirty, false); - if (is_tdp_mmu_enabled(kvm)) - flush |= kvm_tdp_mmu_slot_set_dirty(kvm, memslot); - 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/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c index f8fa1f64e10d..c926c6b899a1 100644 --- a/arch/x86/kvm/mmu/tdp_mmu.c +++ b/arch/x86/kvm/mmu/tdp_mmu.c @@ -1269,60 +1269,6 @@ void kvm_tdp_mmu_clear_dirty_pt_masked(struct kvm *kvm, } /* - * Set the dirty status of all the SPTEs mapping GFNs in the memslot. This is - * only used for PML, and so will involve setting the dirty bit on each SPTE. - * Returns true if an SPTE has been changed and the TLBs need to be flushed. - */ -static bool set_dirty_gfn_range(struct kvm *kvm, struct kvm_mmu_page *root, - gfn_t start, gfn_t end) -{ - struct tdp_iter iter; - u64 new_spte; - bool spte_set = false; - - rcu_read_lock(); - - tdp_root_for_each_pte(iter, root, start, end) { - if (tdp_mmu_iter_cond_resched(kvm, &iter, false)) - continue; - - if (!is_shadow_present_pte(iter.old_spte) || - iter.old_spte & shadow_dirty_mask) - continue; - - new_spte = iter.old_spte | shadow_dirty_mask; - - tdp_mmu_set_spte(kvm, &iter, new_spte); - spte_set = true; - } - - rcu_read_unlock(); - return spte_set; -} - -/* - * Set the dirty status of all the SPTEs mapping GFNs in the memslot. This is - * only used for PML, and so will involve setting the dirty bit on each SPTE. - * Returns true if an SPTE has been changed and the TLBs need to be flushed. - */ -bool kvm_tdp_mmu_slot_set_dirty(struct kvm *kvm, struct kvm_memory_slot *slot) -{ - struct kvm_mmu_page *root; - int root_as_id; - bool spte_set = false; - - for_each_tdp_mmu_root_yield_safe(kvm, root) { - root_as_id = kvm_mmu_page_as_id(root); - if (root_as_id != slot->as_id) - continue; - - spte_set |= set_dirty_gfn_range(kvm, root, slot->base_gfn, - slot->base_gfn + slot->npages); - } - return spte_set; -} - -/* * Clear leaf entries which could be replaced by large mappings, for * GFNs within the slot. */ diff --git a/arch/x86/kvm/mmu/tdp_mmu.h b/arch/x86/kvm/mmu/tdp_mmu.h index d31c5ed81a18..3b761c111bff 100644 --- a/arch/x86/kvm/mmu/tdp_mmu.h +++ b/arch/x86/kvm/mmu/tdp_mmu.h @@ -33,7 +33,6 @@ void kvm_tdp_mmu_clear_dirty_pt_masked(struct kvm *kvm, struct kvm_memory_slot *slot, gfn_t gfn, unsigned long mask, bool wrprot); -bool kvm_tdp_mmu_slot_set_dirty(struct kvm *kvm, struct kvm_memory_slot *slot); void kvm_tdp_mmu_zap_collapsible_sptes(struct kvm *kvm, struct kvm_memory_slot *slot); diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index b9a8c8af9713..dca2c3333ef2 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -10789,7 +10789,18 @@ static void kvm_mmu_slot_apply_flags(struct kvm *kvm, /* * Nothing more to do for RO slots (which can't be dirtied and can't be - * made writable) or CREATE/MOVE/DELETE of a slot. See comments below. + * made writable) or CREATE/MOVE/DELETE of a slot. + * + * For a memslot with dirty logging disabled: + * CREATE: No dirty mappings will already exist. + * MOVE/DELETE: The old mappings will already have been cleaned up by + * kvm_arch_flush_shadow_memslot() + * + * For a memslot with dirty logging enabled: + * CREATE: No shadow pages exist, thus nothing to write-protect + * and no dirty bits to clear. + * MOVE/DELETE: The old mappings will already have been cleaned up by + * kvm_arch_flush_shadow_memslot(). */ if ((change != KVM_MR_FLAGS_ONLY) || (new->flags & KVM_MEM_READONLY)) return; @@ -10802,55 +10813,31 @@ static void kvm_mmu_slot_apply_flags(struct kvm *kvm, if (WARN_ON_ONCE(!((old->flags ^ new->flags) & KVM_MEM_LOG_DIRTY_PAGES))) return; - /* - * Dirty logging tracks sptes in 4k granularity, meaning that large - * sptes have to be split. If live migration is successful, the guest - * in the source machine will be destroyed and large sptes will be - * created in the destination. However, if the guest continues to run - * in the source machine (for example if live migration fails), small - * sptes will remain around and cause bad performance. - * - * Scan sptes if dirty logging has been stopped, dropping those - * which can be collapsed into a single large-page spte. Later - * page faults will create the large-page sptes. - * - * There is no need to do this in any of the following cases: - * CREATE: No dirty mappings will already exist. - * MOVE/DELETE: The old mappings will already have been cleaned up by - * kvm_arch_flush_shadow_memslot() - */ - if (!log_dirty_pages) + if (!log_dirty_pages) { + /* + * Dirty logging tracks sptes in 4k granularity, meaning that + * large sptes have to be split. If live migration succeeds, + * the guest in the source machine will be destroyed and large + * sptes will be created in the destination. However, if the + * guest continues to run in the source machine (for example if + * live migration fails), small sptes will remain around and + * cause bad performance. + * + * Scan sptes if dirty logging has been stopped, dropping those + * which can be collapsed into a single large-page spte. Later + * page faults will create the large-page sptes. + */ kvm_mmu_zap_collapsible_sptes(kvm, new); - - /* - * Enable or disable dirty logging for the slot. - * - * For KVM_MR_DELETE and KVM_MR_MOVE, the shadow pages of the old - * slot have been zapped so no dirty logging updates are needed for - * the old slot. - * For KVM_MR_CREATE and KVM_MR_MOVE, once the new slot is visible - * any mappings that might be created in it will consume the - * properties of the new slot and do not need to be updated here. - * - * When PML is enabled, the kvm_x86_ops dirty logging hooks are - * called to enable/disable dirty logging. - * - * When disabling dirty logging with PML enabled, the D-bit is set - * for sptes in the slot in order to prevent unnecessary GPA - * logging in the PML buffer (and potential PML buffer full VMEXIT). - * This guarantees leaving PML enabled for the guest's lifetime - * won't have any additional overhead from PML when the guest is - * running with dirty logging disabled. - * - * When enabling dirty logging, 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. - */ - if (log_dirty_pages) { + } 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. + */ if (kvm_x86_ops.cpu_dirty_log_size) { if (!kvm_dirty_log_manual_protect_and_init_set(kvm)) kvm_mmu_slot_leaf_clear_dirty(kvm, new); @@ -10870,8 +10857,6 @@ static void kvm_mmu_slot_apply_flags(struct kvm *kvm, */ kvm_mmu_slot_remove_write_access(kvm, new, level); } - } else if (kvm_x86_ops.cpu_dirty_log_size) { - kvm_mmu_slot_set_dirty(kvm, new); } } |