From: Ben Gardon bgardon@google.com
commit 574c3c55e969096cea770eda3375ff35ccf91702 upstream.
When recursively clearing out disconnected pts, the range based TLB flush in handle_removed_tdp_mmu_page uses the wrong starting GFN, resulting in the flush mostly missing the affected range. Fix this by using base_gfn for the flush.
In response to feedback from David Matlack on the RFC version of this patch, also move a few definitions into the for loop in the function to prevent unintended references to them in the future.
Fixes: a066e61f13cf ("KVM: x86/mmu: Factor out handling of removed page tables") CC: stable@vger.kernel.org Signed-off-by: Ben Gardon bgardon@google.com Message-Id: 20211115211704.2621644-1-bgardon@google.com Signed-off-by: Paolo Bonzini pbonzini@redhat.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/x86/kvm/mmu/tdp_mmu.c | 10 ++++------ 1 file changed, 4 insertions(+), 6 deletions(-)
--- a/arch/x86/kvm/mmu/tdp_mmu.c +++ b/arch/x86/kvm/mmu/tdp_mmu.c @@ -316,9 +316,6 @@ static void handle_removed_tdp_mmu_page( struct kvm_mmu_page *sp = sptep_to_sp(rcu_dereference(pt)); int level = sp->role.level; gfn_t base_gfn = sp->gfn; - u64 old_child_spte; - u64 *sptep; - gfn_t gfn; int i;
trace_kvm_mmu_prepare_zap_page(sp); @@ -326,8 +323,9 @@ static void handle_removed_tdp_mmu_page( tdp_mmu_unlink_page(kvm, sp, shared);
for (i = 0; i < PT64_ENT_PER_PAGE; i++) { - sptep = rcu_dereference(pt) + i; - gfn = base_gfn + i * KVM_PAGES_PER_HPAGE(level); + u64 *sptep = rcu_dereference(pt) + i; + gfn_t gfn = base_gfn + i * KVM_PAGES_PER_HPAGE(level); + u64 old_child_spte;
if (shared) { /* @@ -373,7 +371,7 @@ static void handle_removed_tdp_mmu_page( shared); }
- kvm_flush_remote_tlbs_with_address(kvm, gfn, + kvm_flush_remote_tlbs_with_address(kvm, base_gfn, KVM_PAGES_PER_HPAGE(level + 1));
call_rcu(&sp->rcu_head, tdp_mmu_free_sp_rcu_callback);