[Resend PATCH V5 10/10] KVM/MMU: Flush tlb directly in the kvm_zap_gfn_range()

From: lantianyu1986
Date: Thu Dec 06 2018 - 08:22:39 EST


From: Lan Tianyu <Tianyu.Lan@xxxxxxxxxxxxx>

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@xxxxxxxxxxxxx>
---
Change since v4:
Move operation of setting flush_tlb out of for loop.
---
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 64bd848f021e..94b0540b1471 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -5624,8 +5624,13 @@ 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_tlb = true;
+ bool flush = false;
int i;

+ if (kvm_available_flush_tlb_with_range())
+ flush_tlb = false;
+
spin_lock(&kvm->mmu_lock);
for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++) {
slots = __kvm_memslots(kvm, i);
@@ -5637,12 +5642,17 @@ void kvm_zap_gfn_range(struct kvm *kvm, gfn_t gfn_start, gfn_t gfn_end)
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);
+ 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_flush_remote_tlbs_with_address(kvm, gfn_start,
+ gfn_end - gfn_start + 1);
+
spin_unlock(&kvm->mmu_lock);
}

--
2.14.4