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    SubjectRe: [RESEND 2][PATCH 4/4] Modify KVM to update guest time accounting.
    Avi Kivity wrote:
    > Ingo Molnar wrote:
    >> * Avi Kivity <avi@qumranet.com> wrote:
    >>
    >>
    >>> This bit can go; for the external module I can add it back in
    >>> external-module-compat.h. No need to pollute mainline with backward
    >>> compatibility stuff.
    >>>
    >>
    >> hm:
    >>
    >> static inline void kvm_guest_enter(void)
    >> {
    >> current->flags |= PF_VCPU;
    >> }
    >>
    >> static inline void kvm_guest_exit(void)
    >> {
    >> }
    >>
    >> shouldnt PF_VCPU be cleared in kvm_guest_exit()?
    >>
    >
    > IIRC the accounting code clears it, but yes, it may not have been called
    > at all, so clearing it here is needed.
    >

    No, It must not be cleared here because we can't enter in the accounting code
    between kvm_guest_enter(void) and kvm_guest_exit(void).

    This is why the accounting code clears it.

    I put a kvm_guest_exit() only for symmetry.

    Laurent
    --
    ---------------- Laurent.Vivier@bull.net -----------------
    "Given enough eyeballs, all bugs are shallow" E. S. Raymond

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