KVM: x86/mmu: Fix TDP MMU zap collapsible SPTEs

commit 87aa9ec939 upstream.

There is a bug in the TDP MMU function to zap SPTEs which could be
replaced with a larger mapping which prevents the function from doing
anything. Fix this by correctly zapping the last level SPTEs.

Cc: stable@vger.kernel.org
Fixes: 1488199856 ("kvm: x86/mmu: Support disabling dirty logging for the tdp MMU")
Signed-off-by: Ben Gardon <bgardon@google.com>
Message-Id: <20210202185734.1680553-11-bgardon@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Ben Gardon 2021-02-02 10:57:16 -08:00 committed by Greg Kroah-Hartman
parent ff0c437a0e
commit dd7f10523b

View file

@ -1037,8 +1037,8 @@ bool kvm_tdp_mmu_slot_set_dirty(struct kvm *kvm, struct kvm_memory_slot *slot)
}
/*
* Clear non-leaf entries (and free associated page tables) which could
* be replaced by large mappings, for GFNs within the slot.
* Clear leaf entries which could be replaced by large mappings, for
* GFNs within the slot.
*/
static void zap_collapsible_spte_range(struct kvm *kvm,
struct kvm_mmu_page *root,
@ -1050,7 +1050,7 @@ static void zap_collapsible_spte_range(struct kvm *kvm,
tdp_root_for_each_pte(iter, root, start, end) {
if (!is_shadow_present_pte(iter.old_spte) ||
is_last_spte(iter.old_spte, iter.level))
!is_last_spte(iter.old_spte, iter.level))
continue;
pfn = spte_to_pfn(iter.old_spte);