From ae7cd87372a473509aa32ba9ad8bd1401f65d375 Mon Sep 17 00:00:00 2001 From: Xiaoguang Chen Date: Sun, 9 Oct 2016 15:41:44 +0800 Subject: [PATCH 1/3] KVM: x86: add track_flush_slot page track notifier MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit When a memory slot is being moved or removed users of page track can be notified. So users can drop write-protection for the pages in that memory slot. This notifier type is needed by KVMGT to sync up its shadow page table when memory slot is being moved or removed. Register the notifier type track_flush_slot to receive memslot move and remove event. Reviewed-by: Xiao Guangrong Signed-off-by: Chen Xiaoguang [Squashed commits to avoid bisection breakage and reworded the subject.] Signed-off-by: Radim Krčmář --- arch/x86/include/asm/kvm_page_track.h | 9 +++++++++ arch/x86/kvm/mmu.c | 7 +++++++ arch/x86/kvm/page_track.c | 25 +++++++++++++++++++++++++ arch/x86/kvm/x86.c | 2 +- 4 files changed, 42 insertions(+), 1 deletion(-) diff --git a/arch/x86/include/asm/kvm_page_track.h b/arch/x86/include/asm/kvm_page_track.h index c2b8d24a235c..5f66597c71c0 100644 --- a/arch/x86/include/asm/kvm_page_track.h +++ b/arch/x86/include/asm/kvm_page_track.h @@ -32,6 +32,14 @@ struct kvm_page_track_notifier_node { */ void (*track_write)(struct kvm_vcpu *vcpu, gpa_t gpa, const u8 *new, int bytes); + /* + * It is called when memory slot is being moved or removed + * users can drop write-protection for the pages in that memory slot + * + * @kvm: the kvm where memory slot being moved or removed + * @slot: the memory slot being moved or removed + */ + void (*track_flush_slot)(struct kvm *kvm, struct kvm_memory_slot *slot); }; void kvm_page_track_init(struct kvm *kvm); @@ -58,4 +66,5 @@ kvm_page_track_unregister_notifier(struct kvm *kvm, struct kvm_page_track_notifier_node *n); void kvm_page_track_write(struct kvm_vcpu *vcpu, gpa_t gpa, const u8 *new, int bytes); +void kvm_page_track_flush_slot(struct kvm *kvm, struct kvm_memory_slot *slot); #endif diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index d9c7e986b4e4..8ac1fb858b2f 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -4617,11 +4617,18 @@ void kvm_mmu_setup(struct kvm_vcpu *vcpu) init_kvm_mmu(vcpu); } +static void kvm_mmu_invalidate_zap_pages_in_memslot(struct kvm *kvm, + struct kvm_memory_slot *slot) +{ + kvm_mmu_invalidate_zap_all_pages(kvm); +} + void kvm_mmu_init_vm(struct kvm *kvm) { struct kvm_page_track_notifier_node *node = &kvm->arch.mmu_sp_tracker; node->track_write = kvm_mmu_pte_write; + node->track_flush_slot = kvm_mmu_invalidate_zap_pages_in_memslot; kvm_page_track_register_notifier(kvm, node); } diff --git a/arch/x86/kvm/page_track.c b/arch/x86/kvm/page_track.c index b431539c3714..e79bb256d177 100644 --- a/arch/x86/kvm/page_track.c +++ b/arch/x86/kvm/page_track.c @@ -225,3 +225,28 @@ void kvm_page_track_write(struct kvm_vcpu *vcpu, gpa_t gpa, const u8 *new, n->track_write(vcpu, gpa, new, bytes); srcu_read_unlock(&head->track_srcu, idx); } + +/* + * Notify the node that memory slot is being removed or moved so that it can + * drop write-protection for the pages in the memory slot. + * + * The node should figure out it has any write-protected pages in this slot + * by itself. + */ +void kvm_page_track_flush_slot(struct kvm *kvm, struct kvm_memory_slot *slot) +{ + struct kvm_page_track_notifier_head *head; + struct kvm_page_track_notifier_node *n; + int idx; + + head = &kvm->arch.track_notifier_head; + + if (hlist_empty(&head->track_notifier_list)) + return; + + idx = srcu_read_lock(&head->track_srcu); + hlist_for_each_entry_rcu(n, &head->track_notifier_list, node) + if (n->track_flush_slot) + n->track_flush_slot(kvm, slot); + srcu_read_unlock(&head->track_srcu, idx); +} diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 3017de0431bd..7e30c720d0c5 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -8155,7 +8155,7 @@ void kvm_arch_flush_shadow_all(struct kvm *kvm) void kvm_arch_flush_shadow_memslot(struct kvm *kvm, struct kvm_memory_slot *slot) { - kvm_mmu_invalidate_zap_all_pages(kvm); + kvm_page_track_flush_slot(kvm, slot); } static inline bool kvm_vcpu_has_events(struct kvm_vcpu *vcpu) From d126363d8fe946c9bb2538839de9b09f5b3b8ba3 Mon Sep 17 00:00:00 2001 From: Jike Song Date: Tue, 25 Oct 2016 15:50:42 +0800 Subject: [PATCH 2/3] kvm/page_track: call notifiers with kvm_page_track_notifier_node The user of page_track might needs extra information, so pass the kvm_page_track_notifier_node to callbacks. Signed-off-by: Jike Song Reviewed-by: Xiao Guangrong Signed-off-by: Paolo Bonzini --- arch/x86/include/asm/kvm_page_track.h | 7 +++++-- arch/x86/kvm/mmu.c | 6 ++++-- arch/x86/kvm/page_track.c | 4 ++-- 3 files changed, 11 insertions(+), 6 deletions(-) diff --git a/arch/x86/include/asm/kvm_page_track.h b/arch/x86/include/asm/kvm_page_track.h index 5f66597c71c0..d74747b031ec 100644 --- a/arch/x86/include/asm/kvm_page_track.h +++ b/arch/x86/include/asm/kvm_page_track.h @@ -29,17 +29,20 @@ struct kvm_page_track_notifier_node { * @gpa: the physical address written by guest. * @new: the data was written to the address. * @bytes: the written length. + * @node: this node */ void (*track_write)(struct kvm_vcpu *vcpu, gpa_t gpa, const u8 *new, - int bytes); + int bytes, struct kvm_page_track_notifier_node *node); /* * It is called when memory slot is being moved or removed * users can drop write-protection for the pages in that memory slot * * @kvm: the kvm where memory slot being moved or removed * @slot: the memory slot being moved or removed + * @node: this node */ - void (*track_flush_slot)(struct kvm *kvm, struct kvm_memory_slot *slot); + void (*track_flush_slot)(struct kvm *kvm, struct kvm_memory_slot *slot, + struct kvm_page_track_notifier_node *node); }; void kvm_page_track_init(struct kvm *kvm); diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index 8ac1fb858b2f..87c5880ba3b7 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -4405,7 +4405,8 @@ static u64 *get_written_sptes(struct kvm_mmu_page *sp, gpa_t gpa, int *nspte) } static void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa, - const u8 *new, int bytes) + const u8 *new, int bytes, + struct kvm_page_track_notifier_node *node) { gfn_t gfn = gpa >> PAGE_SHIFT; struct kvm_mmu_page *sp; @@ -4618,7 +4619,8 @@ void kvm_mmu_setup(struct kvm_vcpu *vcpu) } static void kvm_mmu_invalidate_zap_pages_in_memslot(struct kvm *kvm, - struct kvm_memory_slot *slot) + struct kvm_memory_slot *slot, + struct kvm_page_track_notifier_node *node) { kvm_mmu_invalidate_zap_all_pages(kvm); } diff --git a/arch/x86/kvm/page_track.c b/arch/x86/kvm/page_track.c index e79bb256d177..3dae0e3d6a58 100644 --- a/arch/x86/kvm/page_track.c +++ b/arch/x86/kvm/page_track.c @@ -222,7 +222,7 @@ void kvm_page_track_write(struct kvm_vcpu *vcpu, gpa_t gpa, const u8 *new, idx = srcu_read_lock(&head->track_srcu); hlist_for_each_entry_rcu(n, &head->track_notifier_list, node) if (n->track_write) - n->track_write(vcpu, gpa, new, bytes); + n->track_write(vcpu, gpa, new, bytes, n); srcu_read_unlock(&head->track_srcu, idx); } @@ -247,6 +247,6 @@ void kvm_page_track_flush_slot(struct kvm *kvm, struct kvm_memory_slot *slot) idx = srcu_read_lock(&head->track_srcu); hlist_for_each_entry_rcu(n, &head->track_notifier_list, node) if (n->track_flush_slot) - n->track_flush_slot(kvm, slot); + n->track_flush_slot(kvm, slot, n); srcu_read_unlock(&head->track_srcu, idx); } From 871b7ef2a1850d0b435c8b324bf4a5d391adde3f Mon Sep 17 00:00:00 2001 From: Jike Song Date: Tue, 25 Oct 2016 15:50:43 +0800 Subject: [PATCH 3/3] kvm/page_track: export symbols for external usage Signed-off-by: Jike Song Reviewed-by: Xiao Guangrong Signed-off-by: Paolo Bonzini --- arch/x86/kvm/page_track.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/arch/x86/kvm/page_track.c b/arch/x86/kvm/page_track.c index 3dae0e3d6a58..4a1c13eaa518 100644 --- a/arch/x86/kvm/page_track.c +++ b/arch/x86/kvm/page_track.c @@ -106,6 +106,7 @@ void kvm_slot_page_track_add_page(struct kvm *kvm, if (kvm_mmu_slot_gfn_write_protect(kvm, slot, gfn)) kvm_flush_remote_tlbs(kvm); } +EXPORT_SYMBOL_GPL(kvm_slot_page_track_add_page); /* * remove the guest page from the tracking pool which stops the interception @@ -135,6 +136,7 @@ void kvm_slot_page_track_remove_page(struct kvm *kvm, */ kvm_mmu_gfn_allow_lpage(slot, gfn); } +EXPORT_SYMBOL_GPL(kvm_slot_page_track_remove_page); /* * check if the corresponding access on the specified guest page is tracked. @@ -181,6 +183,7 @@ kvm_page_track_register_notifier(struct kvm *kvm, hlist_add_head_rcu(&n->node, &head->track_notifier_list); spin_unlock(&kvm->mmu_lock); } +EXPORT_SYMBOL_GPL(kvm_page_track_register_notifier); /* * stop receiving the event interception. It is the opposed operation of @@ -199,6 +202,7 @@ kvm_page_track_unregister_notifier(struct kvm *kvm, spin_unlock(&kvm->mmu_lock); synchronize_srcu(&head->track_srcu); } +EXPORT_SYMBOL_GPL(kvm_page_track_unregister_notifier); /* * Notify the node that write access is intercepted and write emulation is