[PATCH 02/28] KVM: x86/mmu: Skip tlb flush if it has been done in zap_gfn_range()

Sean Christopherson
2021-11-20T04:51:44Z

From: Hou Wenlong <houwenlong93@linux.alibaba.com>

If the parameter flush is set, zap_gfn_range() would flush remote tlb
when yield, then tlb flush is not needed outside. So use the return
value of zap_gfn_range() directly instead of OR on it in
kvm_unmap_gfn_range() and kvm_tdp_mmu_unmap_gfn_range().

Fixes: 3039bcc744980 ("KVM: Move x86's MMU notifier memslot walkers to generic code")
Signed-off-by: Hou Wenlong <houwenlong93@linux.alibaba.com>
---
arch/x86/kvm/mmu/mmu.c | 2 +-
arch/x86/kvm/mmu/tdp_mmu.c | 4 ++--
2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 8f0035517450..457336f67636 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -1582,7 +1582,7 @@ bool kvm_unmap_gfn_range(struct kvm *kvm, struct kvm_gfn_range *range)
flush = kvm_handle_gfn_range(kvm, range, kvm_unmap_rmapp);

if (is_tdp_mmu_enabled(kvm))
- flush |= kvm_tdp_mmu_unmap_gfn_range(kvm, range, flush);
+ flush = kvm_tdp_mmu_unmap_gfn_range(kvm, range, flush);

return flush;
}
diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c
index a29ebff1cfa0..4cd6bf7e73f0 100644
--- a/arch/x86/kvm/mmu/tdp_mmu.c
+++ b/arch/x86/kvm/mmu/tdp_mmu.c
@@ -1032,8 +1032,8 @@ bool kvm_tdp_mmu_unmap_gfn_range(struct kvm *kvm, struct kvm_gfn_range *range,
struct kvm_mmu_page *root;

for_each_tdp_mmu_root_yield_safe(kvm, root, range->slot->as_id, false)
- flush |= zap_gfn_range(kvm, root, range->start, range->end,
- range->may_block, flush, false);
+ flush = zap_gfn_range(kvm, root, range->start, range->end,
+ range->may_block, flush, false);

return flush;
}
--
2.34.0.rc2.393.gf8c9666880-goog