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    Subject[PATCH 01/15] KVM: X86: Ensure the dirty PDPTEs to be loaded
    Date
    From: Lai Jiangshan <laijs@linux.alibaba.com>

    For VMX, the dirty PDPTEs needs to be loaded before the coming VMENTER
    via vmx_load_mmu_pgd() if EPT is enabled.

    But not all paths that call load_pdptrs() will cause vmx_load_mmu_pgd()
    to be invoked. Normally, kvm_mmu_reset_context() and KVM_REQ_LOAD_MMU_PGD
    are used to launch later vmx_load_mmu_pgd().

    The commit d81135a57aa6("KVM: x86: do not reset mmu if CR0.CD and
    CR0.NW are changed") skips kvm_mmu_reset_context() after load_pdptrs()
    when changing CR0.CD and CR0.NW.

    The commit 21823fbda552("KVM: x86: Invalidate all PGDs for the current
    PCID on MOV CR3 w/ flush") skips KVM_REQ_LOAD_MMU_PGD after
    load_pdptrs() when rewriting the CR3 with the same value.

    The commit a91a7c709600("KVM: X86: Don't reset mmu context when
    toggling X86_CR4_PGE") skips kvm_mmu_reset_context() after
    load_pdptrs() when changing CR4.PGE.

    Fixes: d81135a57aa6("KVM: x86: do not reset mmu if CR0.CD and CR0.NW are changed")
    Fixes: 21823fbda552("KVM: x86: Invalidate all PGDs for the current PCID on MOV CR3 w/ flush")
    Fixes: a91a7c709600("KVM: X86: Don't reset mmu context when toggling X86_CR4_PGE")
    Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com>
    ---
    arch/x86/kvm/x86.c | 2 ++
    1 file changed, 2 insertions(+)

    diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
    index ac83d873d65b..034c233ea5a1 100644
    --- a/arch/x86/kvm/x86.c
    +++ b/arch/x86/kvm/x86.c
    @@ -830,6 +830,8 @@ int load_pdptrs(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu, unsigned long cr3)

    memcpy(mmu->pdptrs, pdpte, sizeof(mmu->pdptrs));
    kvm_register_mark_dirty(vcpu, VCPU_EXREG_PDPTR);
    + /* Ensure the dirty PDPTEs to be loaded. */
    + kvm_make_request(KVM_REQ_LOAD_MMU_PGD, vcpu);
    vcpu->arch.pdptrs_from_userspace = false;

    return 1;
    --
    2.19.1.6.gb485710b
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