From: Yanan Wang <[email protected]>

When dirty logging is enabled, we collapse block entries into tables
as necessary. If dirty logging gets canceled, we can end-up merging
tables back into block entries.

When this happens, we must not only free the non-huge page-table
pages but also invalidate all the TLB entries that can potentially
cover the block. Otherwise, we end-up with multiple possible translations
for the same physical page, which can legitimately result in a TLB
conflict.

To address this, replease the bogus invalidation by IPA with a full
VM invalidation. Although this is pretty heavy handed, it happens
very infrequently and saves a bunch of invalidations by IPA.

Signed-off-by: Yanan Wang <[email protected]>
[maz: fixup commit message]
Signed-off-by: Marc Zyngier <[email protected]>
Acked-by: Will Deacon <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
---
 arch/arm64/kvm/hyp/pgtable.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/kvm/hyp/pgtable.c b/arch/arm64/kvm/hyp/pgtable.c
index 2beba1dc40ec..bdf8e55ed308 100644
--- a/arch/arm64/kvm/hyp/pgtable.c
+++ b/arch/arm64/kvm/hyp/pgtable.c
@@ -502,7 +502,13 @@ static int stage2_map_walk_table_pre(u64 addr, u64 end, 
u32 level,
                return 0;
 
        kvm_set_invalid_pte(ptep);
-       kvm_call_hyp(__kvm_tlb_flush_vmid_ipa, data->mmu, addr, 0);
+
+       /*
+        * Invalidate the whole stage-2, as we may have numerous leaf
+        * entries below us which would otherwise need invalidating
+        * individually.
+        */
+       kvm_call_hyp(__kvm_tlb_flush_vmid, data->mmu);
        data->anchor = ptep;
        return 0;
 }
-- 
2.28.0

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