diff options
| author | Sean Christopherson <seanjc@google.com> | 2021-01-13 12:50:30 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-02-26 10:13:00 +0100 |
| commit | d2cbae37c3d8f9ce1f33ae690421be6ecf3809d1 (patch) | |
| tree | 344ebb9469cadf31f52fde20e8914da9237ee8f3 /mm/memory.c | |
| parent | 729fbb8cb27654c75171d6fa4d9cdfe10bc212eb (diff) | |
KVM: x86: Zap the oldest MMU pages, not the newest
commit 8fc517267fb28576dfca2380cc2497a2454b8fae upstream.
Walk the list of MMU pages in reverse in kvm_mmu_zap_oldest_mmu_pages().
The list is FIFO, meaning new pages are inserted at the head and thus
the oldest pages are at the tail. Using a "forward" iterator causes KVM
to zap MMU pages that were just added, which obliterates guest
performance once the max number of shadow MMU pages is reached.
Fixes: 6b82ef2c9cf1 ("KVM: x86/mmu: Batch zap MMU pages when recycling oldest pages")
Reported-by: Zdenek Kaspar <zkaspar82@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20210113205030.3481307-1-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'mm/memory.c')
0 files changed, 0 insertions, 0 deletions