[v8,1/5] ptp_kvm: probe for kvm guest availability

Commit Message

Joao Martins Nov. 8, 2017, 5:19 p.m. UTC

In the event of moving pvclock_pvti_cpu0_va() definition to common
pvclock code, this function would return a value on non KVM guests.
Later on this would fail with a GPF on ptp_kvm_init when running on a
Xen guest. Therefore, ptp_kvm_init() should check whether it is running
in a KVM guest.

Signed-off-by: Joao Martins <[e-mail]>
Acked-by: Radim Krčmář <[e-mail]>
---
Changes since v7:
 * Add Radim's Acked-by
---
 drivers/ptp/ptp_kvm.c | 3 +++
 1 file changed, 3 insertions(+)

Patch

diff --git a/drivers/ptp/ptp_kvm.c b/drivers/ptp/ptp_kvm.c
index 2b1b212c219e..e04d7b2ecb3a 100644
--- a/drivers/ptp/ptp_kvm.c
+++ b/drivers/ptp/ptp_kvm.c
@@ -178,6 +178,9 @@  static int __init ptp_kvm_init(void)
 {
 	long ret;
 
+	if (!kvm_para_available())
+		return -ENODEV;
+
 	clock_pair_gpa = slow_virt_to_phys(&clock_pair);
 	hv_clock = pvclock_pvti_cpu0_va();