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    Subject[PATCH RESEND v4 9/9] KVM: MMU: Handle host memory remapping and reclaim
    Date
    Host page swapping/migration may change the translation in
    EPT leaf entry, if the target page is SPP protected,
    re-enable SPP protection in MMU notifier. If SPPT shadow
    page is reclaimed, the level1 pages don't have rmap to clear.

    Signed-off-by: Yang Weijiang <weijiang.yang@intel.com>
    ---
    arch/x86/kvm/mmu.c | 22 ++++++++++++++++++++++
    1 file changed, 22 insertions(+)

    diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
    index f017fe6cd67b..6aab8902c808 100644
    --- a/arch/x86/kvm/mmu.c
    +++ b/arch/x86/kvm/mmu.c
    @@ -1926,6 +1926,24 @@ static int kvm_set_pte_rmapp(struct kvm *kvm, struct kvm_rmap_head *rmap_head,
    new_spte &= ~PT_WRITABLE_MASK;
    new_spte &= ~SPTE_HOST_WRITEABLE;

    + /*
    + * if it's EPT leaf entry and the physical page is
    + * SPP protected, then re-enable SPP protection for
    + * the page.
    + */
    + if (kvm->arch.spp_active &&
    + level == PT_PAGE_TABLE_LEVEL) {
    + struct kvm_subpage spp_info = {0};
    + int i;
    +
    + spp_info.base_gfn = gfn;
    + spp_info.npages = 1;
    + i = kvm_mmu_get_subpages(kvm, &spp_info, true);
    + if (i == 1 &&
    + spp_info.access_map[0] != FULL_SPP_ACCESS)
    + new_spte |= PT_SPP_MASK;
    + }
    +
    new_spte = mark_spte_for_access_track(new_spte);

    mmu_spte_clear_track_bits(sptep);
    @@ -2809,6 +2827,10 @@ static bool mmu_page_zap_pte(struct kvm *kvm, struct kvm_mmu_page *sp,
    pte = *spte;
    if (is_shadow_present_pte(pte)) {
    if (is_last_spte(pte, sp->role.level)) {
    + /* SPPT leaf entries don't have rmaps*/
    + if (sp->role.level == PT_PAGE_TABLE_LEVEL &&
    + is_spp_spte(sp))
    + return true;
    drop_spte(kvm, spte);
    if (is_large_pte(pte))
    --kvm->stat.lpages;
    --
    2.17.2
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