From f285c633cb6d68d2bf3a8ad65bee3835aac9886c Mon Sep 17 00:00:00 2001
From: Ben Gardon <bgardon@google.com>
Date: Tue, 12 Mar 2019 11:45:59 -0700
Subject: [PATCH] kvm: mmu: Used range based flushing in
slot_handle_level_range
Replace kvm_flush_remote_tlbs with kvm_flush_remote_tlbs_with_address
in slot_handle_level_range. When range based flushes are not enabled
kvm_flush_remote_tlbs_with_address falls back to kvm_flush_remote_tlbs.
This changes the behavior of many functions that indirectly use
slot_handle_level_range, iff the range based flushes are enabled. The
only potential problem I see with this is that kvm->tlbs_dirty will be
cleared less often, however the only caller of slot_handle_level_range that
checks tlbs_dirty is kvm_mmu_notifier_invalidate_range_start which
checks it and does a kvm_flush_remote_tlbs after calling
kvm_unmap_hva_range anyway.
Tested: Ran all kvm-unit-tests on a Intel Haswell machine with and
without this patch. The patch introduced no new failures.
Signed-off-by: Ben Gardon <bgardon@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
arch/x86/kvm/mmu.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 5a9981465fbb5..eee455a8a612d 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -5526,7 +5526,9 @@ slot_handle_level_range(struct kvm *kvm, struct kvm_memory_slot *memslot,
if (need_resched() || spin_needbreak(&kvm->mmu_lock)) {
if (flush && lock_flush_tlb) {
- kvm_flush_remote_tlbs(kvm);
+ kvm_flush_remote_tlbs_with_address(kvm,
+ start_gfn,
+ iterator.gfn - start_gfn + 1);
flush = false;
}
cond_resched_lock(&kvm->mmu_lock);
@@ -5534,7 +5536,8 @@ slot_handle_level_range(struct kvm *kvm, struct kvm_memory_slot *memslot,
}
if (flush && lock_flush_tlb) {
- kvm_flush_remote_tlbs(kvm);
+ kvm_flush_remote_tlbs_with_address(kvm, start_gfn,
+ end_gfn - start_gfn + 1);
flush = false;
}
--
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