linux-kernel - [PATCH 9/13] KVM/MMU: Replace tlb flush function with range list flush function

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Message-ID: <20180910083806.65177-10-Tianyu.Lan@microsoft.com>
Date:   Mon, 10 Sep 2018 08:39:21 +0000
From:   Tianyu Lan <Tianyu.Lan@...rosoft.com>
To:     unlisted-recipients:; (no To-header on input)
CC:     Tianyu Lan <Tianyu.Lan@...rosoft.com>,
        KY Srinivasan <kys@...rosoft.com>,
        Haiyang Zhang <haiyangz@...rosoft.com>,
        Stephen Hemminger <sthemmin@...rosoft.com>,
        "tglx@...utronix.de" <tglx@...utronix.de>,
        "mingo@...hat.com" <mingo@...hat.com>,
        "hpa@...or.com" <hpa@...or.com>, "x86@...nel.org" <x86@...nel.org>,
        "pbonzini@...hat.com" <pbonzini@...hat.com>,
        "rkrcmar@...hat.com" <rkrcmar@...hat.com>,
        "devel@...uxdriverproject.org" <devel@...uxdriverproject.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "kvm@...r.kernel.org" <kvm@...r.kernel.org>,
        "Michael Kelley (EOSG)" <Michael.H.Kelley@...rosoft.com>,
        vkuznets <vkuznets@...hat.com>,
        Jork Loeser <Jork.Loeser@...rosoft.com>
Subject: [PATCH 9/13] KVM/MMU: Replace tlb flush function with range list
 flush function

This patch is to use range list flush function in the
mmu_sync_children(), kvm_mmu_commit_zap_page() and
FNAME(sync_page)().

Signed-off-by: Lan Tianyu <Tianyu.Lan@...rosoft.com>
---
 arch/x86/kvm/mmu.c         | 26 +++++++++++++++++++++++---
 arch/x86/kvm/paging_tmpl.h |  5 ++++-
 2 files changed, 27 insertions(+), 4 deletions(-)

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 73e19ce589e7..a071da797a15 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -1092,6 +1092,13 @@ static void update_gfn_disallow_lpage_count(struct kvm_memory_slot *slot,
 	}
 }
 
+static void kvm_mmu_queue_flush_request(struct kvm_mmu_page *sp,
+		struct list_head *flush_list)
+{
+	if (sp->sptep && is_last_spte(*sp->sptep, sp->role.level))
+		list_add(&sp->flush_link, flush_list);
+}
+
 void kvm_mmu_gfn_disallow_lpage(struct kvm_memory_slot *slot, gfn_t gfn)
 {
 	update_gfn_disallow_lpage_count(slot, gfn, 1);
@@ -2373,12 +2380,16 @@ static void mmu_sync_children(struct kvm_vcpu *vcpu,
 
 	while (mmu_unsync_walk(parent, &pages)) {
 		bool protected = false;
+		LIST_HEAD(flush_list);
 
-		for_each_sp(pages, sp, parents, i)
+		for_each_sp(pages, sp, parents, i) {
 			protected |= rmap_write_protect(vcpu, sp->gfn);
+			kvm_mmu_queue_flush_request(sp, &flush_list);
+		}
 
 		if (protected) {
-			kvm_flush_remote_tlbs(vcpu->kvm);
+			kvm_flush_remote_tlbs_with_list(vcpu->kvm,
+					&flush_list);
 			flush = false;
 		}
 
@@ -2715,6 +2726,7 @@ 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;
@@ -2728,7 +2740,15 @@ 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)
+			kvm_mmu_queue_flush_request(sp, &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);
diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h
index bb8c2cdf70c3..aa450e0596a4 100644
--- a/arch/x86/kvm/paging_tmpl.h
+++ b/arch/x86/kvm/paging_tmpl.h
@@ -976,6 +976,7 @@ static int FNAME(sync_page)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp)
 	bool host_writable;
 	gpa_t first_pte_gpa;
 	int set_spte_ret = 0;
+	LIST_HEAD(flush_list);
 
 	/* direct kvm_mmu_page can not be unsync. */
 	BUG_ON(sp->role.direct);
@@ -1036,10 +1037,12 @@ static int FNAME(sync_page)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp)
 					 pte_access, PT_PAGE_TABLE_LEVEL,
 					 gfn, spte_to_pfn(sp->spt[i]),
 					 true, false, host_writable);
+		if (set_spte_ret && kvm_available_flush_tlb_with_range())
+			kvm_mmu_queue_flush_request(sp, &flush_list);
 	}
 
 	if (set_spte_ret & SET_SPTE_NEED_REMOTE_TLB_FLUSH)
-		kvm_flush_remote_tlbs(vcpu->kvm);
+		kvm_flush_remote_tlbs_with_list(vcpu->kvm, &flush_list);
 
 	return nr_present;
 }
-- 
2.14.4