From: Joao Martins <joao.m.martins@oracle.com>
Date: Wed, 8 Nov 2017 17:19:54 +0000 (+0000)
Subject: ptp_kvm: probe for kvm guest availability
X-Git-Tag: v4.14.97~9
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=45c40a96b98568f4b0fc79b24d9595ae01ccad68;p=platform%2Fkernel%2Flinux-rpi.git

ptp_kvm: probe for kvm guest availability

commit 001f60e1f662a6dee1630a2915401aaf5959d479 upstream.

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 <joao.m.martins@oracle.com>
Acked-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/ptp/ptp_kvm.c b/drivers/ptp/ptp_kvm.c
index 2b1b212..e04d7b2 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();