[PATCH 5.15 152/207] KVM: x86/mmu: Skip tlb flush if it has been done in zap_gfn_range()

Greg Kroah-Hartman
2021-12-06T15:53:12Z

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

[ Upstream commit c7785d85b6c6cc9f3d0f1a8cab128f4062b30abb ]

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>
Message-Id: <5e16546e228877a4d974f8c0e448a93d52c7a5a9.1637140154.git.houwenlong93@linux.alibaba.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
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 9fb69546e21b8..9d04474b00272 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -1592,7 +1592,7 @@ 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 838603a653b9a..aa75689a91b4c 100644
--- a/arch/x86/kvm/mmu/tdp_mmu.c
+++ b/arch/x86/kvm/mmu/tdp_mmu.c
@@ -1081,8 +1081,8 @@ 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(kvm, root, range->slot->as_id)
- 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;
}
--
2.33.0