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Commit 1aa4bb91 authored by David Matlack's avatar David Matlack Committed by Sean Christopherson
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KVM: x86/mmu: Fix off-by-1 when splitting huge pages during CLEAR



Fix an off-by-1 error when passing in the range of pages to
kvm_mmu_try_split_huge_pages() during CLEAR_DIRTY_LOG. Specifically, end
is the last page that needs to be split (inclusive) so pass in `end + 1`
since kvm_mmu_try_split_huge_pages() expects the `end` to be
non-inclusive.

At worst this will cause a huge page to be write-protected instead of
eagerly split, which is purely a performance issue, not a correctness
issue. But even that is unlikely as it would require userspace pass in a
bitmap where the last page is the only 4K page on a huge page that needs
to be split.

Reported-by: default avatarVipin Sharma <vipinsh@google.com>
Fixes: cb00a70b ("KVM: x86/mmu: Split huge pages mapped by the TDP MMU during KVM_CLEAR_DIRTY_LOG")
Signed-off-by: default avatarDavid Matlack <dmatlack@google.com>
Link: https://lore.kernel.org/r/20231027172640.2335197-2-dmatlack@google.com


Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
parent e9e60c82
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