From 4306f200c71b959c44c32c8a0048fd5857a357c5 Mon Sep 17 00:00:00 2001 From: Radim Krčmář Date: Wed, 15 Feb 2017 20:27:20 +0100 Subject: ptp_kvm: try to detect hypercall availability MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit No point in registering the device if it cannot work. The hypercall does not advertise itself, so we have to call it. Signed-off-by: Radim Krčmář Signed-off-by: Paolo Bonzini --- drivers/ptp/ptp_kvm.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/ptp/ptp_kvm.c b/drivers/ptp/ptp_kvm.c index 0a54e8326a90..09b4df74291e 100644 --- a/drivers/ptp/ptp_kvm.c +++ b/drivers/ptp/ptp_kvm.c @@ -176,12 +176,19 @@ static void __exit ptp_kvm_exit(void) static int __init ptp_kvm_init(void) { + long ret; + clock_pair_gpa = slow_virt_to_phys(&clock_pair); hv_clock = pvclock_pvti_cpu0_va(); if (!hv_clock) return -ENODEV; + ret = kvm_hypercall2(KVM_HC_CLOCK_PAIRING, clock_pair_gpa, + KVM_CLOCK_PAIRING_WALLCLOCK); + if (ret == -KVM_ENOSYS || ret == -KVM_EOPNOTSUPP) + return -ENODEV; + kvm_ptp_clock.caps = ptp_kvm_caps; kvm_ptp_clock.ptp_clock = ptp_clock_register(&kvm_ptp_clock.caps, NULL); -- cgit v1.2.3