d4b2d3035a
Add vDSO support for timekeeping devices that support the KVM/XEN paravirtual clock API. Also, expose, in the userspace-accessible '<machine/pvclock.h>', definitions that will be needed by 'libc' to support 'VDSO_TH_ALGO_X86_PVCLK'. Sponsored by: Juniper Networks, Inc. Sponsored by: Klara, Inc. Reviewed by: kib Differential Revision: https://reviews.freebsd.org/D31418