KVM: x86: Activate master clock immediately on vCPU creation

Previously, the master clock was only activated when the first vCPU
processed KVM_REQ_MASTERCLOCK_UPDATE during KVM_RUN. This meant that
KVM_GET_CLOCK could not return the host_tsc field until after the
first KVM_RUN, making it impossible for userspace to follow the
documented TSC migration procedure without a dummy vCPU run.

Fix this by calling kvm_update_masterclock() directly from
kvm_arch_vcpu_postcreate(), after kvm_synchronize_tsc() has already
set all_vcpus_matched_freq. This ensures the master clock is active
immediately, and KVM_GET_CLOCK returns a valid {host_tsc, realtime}
pair as soon as a vCPU exists.

Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Link: https://patch.msgid.link/20260826213303.914988-5-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>

0 files changed, 0 insertions, 0 deletions