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    SubjectRe: [PATCH 1/3] include files for kvmclock
    > +/*
    > + * Guest has page alignment and padding requirements. At the host, it will
    > + * only lead to wasted space at the vcpu struct. For this reason, the struct
    > + * is not anonymous
    > + */
    > +union kvm_hv_clock {
    > + struct kvm_hv_clock_s {
    > + u64 tsc_mult;
    > + u64 now_ns;
    > + /* That's the wall clock, not the water closet */
    > + u64 wc_sec;
    > + u64 last_tsc;
    > + /* At first, we could use the tsc value as a marker, but Jeremy
    > + * well noted that it will cause us locking problems in 32-bit
    > + * sys, so we have a special version field */
    > + u32 version;
    > + } fields;
    > + char page_align[PAGE_SIZE];
    > +};

    What is the point in using a whole page per vcpu? You probably don't
    want struct kvm_hv_clock_s cross a page border. Is that the only reason
    or are there other constrains too?

    As the kvm clock looks quite simliar to what xen does, how about making
    the structs binary-compatible or simply reuse the xen version (struct
    vcpu_time_info in xen/interface/xen.h)?

    cheers,
    Gerd
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