[4/11] KVM/MMU: Introduce tlb flush with range list

Message ID 20190104085405.40356-5-Tianyu.Lan@microsoft.com
State New
Headers show
Series
  • X86/KVM/Hyper-V: Add HV ept tlb range list flush support in KVM
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Commit Message

Tianyu Lan Jan. 4, 2019, 8:53 a.m.
From: Lan Tianyu <Tianyu.Lan@microsoft.com>

This patch is to introduce tlb flush with range list interface and use
struct kvm_mmu_page as list entry. Use flush list function in the
kvm_mmu_commit_zap_page().

Signed-off-by: Lan Tianyu <Tianyu.Lan@microsoft.com>
---
 arch/x86/include/asm/kvm_host.h |  7 +++++++
 arch/x86/kvm/mmu.c              | 24 +++++++++++++++++++++++-
 2 files changed, 30 insertions(+), 1 deletion(-)

Comments

Paolo Bonzini Jan. 7, 2019, 4:39 p.m. | #1
On 04/01/19 09:53, lantianyu1986@gmail.com wrote:
>  struct kvm_mmu_page {
>  	struct list_head link;
> +
> +	/*
> +	 * Tlb flush with range list uses struct kvm_mmu_page as list entry
> +	 * and all list operations should be under protection of mmu_lock.
> +	 */
> +	struct list_head flush_link;
>  	struct hlist_node hash_link;
>  	bool unsync;
>  
> @@ -443,6 +449,7 @@ struct kvm_mmu {

Again, it would be nice not to grow the struct too much, though I
understand that it's already relatively big (168 bytes).

Can you at least make this an hlist, so that it only takes a single word?

Paolo

Patch

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 78d2a6714c3b..22dbaa8fba32 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -316,6 +316,12 @@  struct kvm_rmap_head {
 
 struct kvm_mmu_page {
 	struct list_head link;
+
+	/*
+	 * Tlb flush with range list uses struct kvm_mmu_page as list entry
+	 * and all list operations should be under protection of mmu_lock.
+	 */
+	struct list_head flush_link;
 	struct hlist_node hash_link;
 	bool unsync;
 
@@ -443,6 +449,7 @@  struct kvm_mmu {
 struct kvm_tlb_range {
 	u64 start_gfn;
 	u64 pages;
+	struct list_head *flush_list;
 };
 
 enum pmc_type {
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 068694fa2371..d3272c5066ea 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -289,6 +289,17 @@  static void kvm_flush_remote_tlbs_with_address(struct kvm *kvm,
 
 	range.start_gfn = start_gfn;
 	range.pages = pages;
+	range.flush_list = NULL;
+
+	kvm_flush_remote_tlbs_with_range(kvm, &range);
+}
+
+static void kvm_flush_remote_tlbs_with_list(struct kvm *kvm,
+		struct list_head *flush_list)
+{
+	struct kvm_tlb_range range;
+
+	range.flush_list = flush_list;
 
 	kvm_flush_remote_tlbs_with_range(kvm, &range);
 }
@@ -2708,6 +2719,7 @@  static void kvm_mmu_commit_zap_page(struct kvm *kvm,
 				    struct list_head *invalid_list)
 {
 	struct kvm_mmu_page *sp, *nsp;
+	LIST_HEAD(flush_list);
 
 	if (list_empty(invalid_list))
 		return;
@@ -2721,7 +2733,17 @@  static void kvm_mmu_commit_zap_page(struct kvm *kvm,
 	 * In addition, kvm_flush_remote_tlbs waits for all vcpus to exit
 	 * guest mode and/or lockless shadow page table walks.
 	 */
-	kvm_flush_remote_tlbs(kvm);
+	if (kvm_available_flush_tlb_with_range()) {
+		list_for_each_entry(sp, invalid_list, link)
+			if (sp->sptep && is_last_spte(*sp->sptep,
+			    sp->role.level))
+				list_add(&sp->flush_link, &flush_list);
+
+		if (!list_empty(&flush_list))
+			kvm_flush_remote_tlbs_with_list(kvm, &flush_list);
+	} else {
+		kvm_flush_remote_tlbs(kvm);
+	}
 
 	list_for_each_entry_safe(sp, nsp, invalid_list, link) {
 		WARN_ON(!sp->role.invalid || sp->root_count);