linux-kernel - [PATCH V3 5/13] KVM/MMU: Flush tlb directly in the kvm_zap_gfn

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Date:   Thu, 27 Sep 2018 03:49:17 +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 V3 5/13] KVM/MMU: Flush tlb directly in the
 kvm_zap_gfn_range()

Originally, flush tlb is done by slot_handle_level_range(). This patch
is to flush tlb directly in the kvm_zap_gfn_range() when range
flush is available.

Signed-off-by: Lan Tianyu <Tianyu.Lan@...rosoft.com>
---
 arch/x86/kvm/mmu.c | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 877edae0401f..f24101ef763e 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -5578,6 +5578,7 @@ void kvm_zap_gfn_range(struct kvm *kvm, gfn_t gfn_start, gfn_t gfn_end)
 {
 	struct kvm_memslots *slots;
 	struct kvm_memory_slot *memslot;
+	bool flush = false;
 	int i;
 
 	spin_lock(&kvm->mmu_lock);
@@ -5585,18 +5586,27 @@ void kvm_zap_gfn_range(struct kvm *kvm, gfn_t gfn_start, gfn_t gfn_end)
 		slots = __kvm_memslots(kvm, i);
 		kvm_for_each_memslot(memslot, slots) {
 			gfn_t start, end;
+			bool flush_tlb = true;
 
 			start = max(gfn_start, memslot->base_gfn);
 			end = min(gfn_end, memslot->base_gfn + memslot->npages);
 			if (start >= end)
 				continue;
 
-			slot_handle_level_range(kvm, memslot, kvm_zap_rmapp,
-						PT_PAGE_TABLE_LEVEL, PT_MAX_HUGEPAGE_LEVEL,
-						start, end - 1, true);
+			if (kvm_available_flush_tlb_with_range())
+				flush_tlb = false;
+
+			flush = slot_handle_level_range(kvm, memslot,
+					kvm_zap_rmapp, PT_PAGE_TABLE_LEVEL,
+					PT_MAX_HUGEPAGE_LEVEL, start,
+					end - 1, flush_tlb);
 		}
 	}
 
+	if (flush && kvm_available_flush_tlb_with_range())
+		kvm_flush_remote_tlbs_with_address(kvm, gfn_start,
+				gfn_end - gfn_start + 1);
+
 	spin_unlock(&kvm->mmu_lock);
 }
 
-- 
2.14.4