• Alex Williamson's avatar
    KVM: unmap pages from the iommu when slots are removed · 32f6daad
    Alex Williamson authored
    We've been adding new mappings, but not destroying old mappings.
    This can lead to a page leak as pages are pinned using
    get_user_pages, but only unpinned with put_page if they still
    exist in the memslots list on vm shutdown.  A memslot that is
    destroyed while an iommu domain is enabled for the guest will
    therefore result in an elevated page reference count that is
    never cleared.
    
    Additionally, without this fix, the iommu is only programmed
    with the first translation for a gpa.  This can result in
    peer-to-peer errors if a mapping is destroyed and replaced by a
    new mapping at the same gpa as the iommu will still be pointing
    to the original, pinned memory address.
    Signed-off-by: default avatarAlex Williamson <alex.williamson@redhat.com>
    Signed-off-by: default avatarMarcelo Tosatti <mtosatti@redhat.com>
    32f6daad
iommu.c 8.11 KB