Changes since v2: - Fix the issue by using master_kernel_ns/get_kvmclock_base_ns() instead of get_kvmclock_ns() when handling KVM_SET_CLOCK. - Rebase on Paolo's "KVM: x86: fix lockdep splat due to Xen runstate update" series and use spin_lock_irq()/spin_unlock_irq() [Paolo] Original description: I discovered that after KVM_SET_CLOCK(0) TSC page value in the guest can go through the roof and apparently we have a signedness issue when the update is performed. Fix the issue and add a selftest. Vitaly Kuznetsov (2): KVM: x86: Prevent 'hv_clock->system_time' from going negative in kvm_guest_time_update() selftests: kvm: Check that TSC page value is small after KVM_SET_CLOCK(0) arch/x86/kvm/x86.c | 19 +++++++++++++++++-- .../selftests/kvm/x86_64/hyperv_clock.c | 13 +++++++++++-- 2 files changed, 28 insertions(+), 4 deletions(-) -- 2.30.2