KVM: x86/mmu: Check for leaf SPTE when clearing dirty bit in the TDP MMU

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Re-check that the given SPTE is still a leaf and present SPTE after a
failed cmpxchg in clear_dirty_gfn_range(). clear_dirty_gfn_range()
intends to only operate on present leaf SPTEs, but that could change
after a failed cmpxchg.

A check for present was added in commit 3354ef5a59 ("KVM: x86/mmu:
Check for present SPTE when clearing dirty bit in TDP MMU") but the
check for leaf is still buried in tdp_root_for_each_leaf_pte() and does
not get rechecked on retry.

Fixes: a6a0b05da9 ("kvm: x86/mmu: Support dirty logging for the TDP MMU")
Signed-off-by: David Matlack <dmatlack@google.com>
Link: https://lore.kernel.org/r/20231027172640.2335197-3-dmatlack@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>

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David Matlack 2023-10-27 10:26:39 -07:00 • committed by Sean Christopherson

parent 1aa4bb9168

commit 45a61ebb22

1 changed files with 4 additions and 3 deletions

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arch/x86/kvm/mmu/tdp_mmu.c

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