diff options
| author | Sean Christopherson <seanjc@google.com> | 2022-02-26 01:15:20 +0100 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2022-03-08 15:31:17 +0100 |
| commit | 3354ef5a592d219364cf442c2f784ce7ad7629fd (patch) | |
| tree | b01dcfa6f7ab94d3eccabc9661d800bcc886b364 /arch/x86/kvm/mmu/tdp_mmu.c | |
| parent | KVM: use __vcalloc for very large allocations (diff) | |
| download | linux-3354ef5a592d219364cf442c2f784ce7ad7629fd.tar.xz linux-3354ef5a592d219364cf442c2f784ce7ad7629fd.zip | |
KVM: x86/mmu: Check for present SPTE when clearing dirty bit in TDP MMU
Explicitly check for present SPTEs when clearing dirty bits in the TDP
MMU. This isn't strictly required for correctness, as setting the dirty
bit in a defunct SPTE will not change the SPTE from !PRESENT to PRESENT.
However, the guarded MMU_WARN_ON() in spte_ad_need_write_protect() would
complain if anyone actually turned on KVM's MMU debugging.
Fixes: a6a0b05da9f3 ("kvm: x86/mmu: Support dirty logging for the TDP MMU")
Cc: Ben Gardon <bgardon@google.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Ben Gardon <bgardon@google.com>
Message-Id: <20220226001546.360188-3-seanjc@google.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kvm/mmu/tdp_mmu.c')
| -rw-r--r-- | arch/x86/kvm/mmu/tdp_mmu.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c index debf08212f12..4cf0cc04b2a0 100644 --- a/arch/x86/kvm/mmu/tdp_mmu.c +++ b/arch/x86/kvm/mmu/tdp_mmu.c @@ -1468,6 +1468,9 @@ retry: if (tdp_mmu_iter_cond_resched(kvm, &iter, false, true)) continue; + if (!is_shadow_present_pte(iter.old_spte)) + continue; + if (spte_ad_need_write_protect(iter.old_spte)) { if (is_writable_pte(iter.old_spte)) new_spte = iter.old_spte & ~PT_WRITABLE_MASK; |