Commit Graph

6 Commits

Author SHA1 Message Date
Joao Martins 9f08890ab9 x86/pvclock: add setter for pvclock_pvti_cpu0_va
Right now there is only a pvclock_pvti_cpu0_va() which is defined
on kvmclock since:

commit dac16fba6f
("x86/vdso: Get pvclock data from the vvar VMA instead of the fixmap")

The only user of this interface so far is kvm. This commit adds a
setter function for the pvti page and moves pvclock_pvti_cpu0_va
to pvclock, which is a more generic place to have it; and would
allow other PV clocksources to use it, such as Xen.

While moving pvclock_pvti_cpu0_va into pvclock, rename also this
function to pvclock_get_pvti_cpu0_va (including its call sites)
to be symmetric with the setter (pvclock_set_pvti_cpu0_va).

Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Acked-by: Andy Lutomirski <luto@kernel.org>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
2017-11-08 16:33:14 -05:00
Joao Martins 001f60e1f6 ptp_kvm: probe for kvm guest availability
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>
2017-11-08 16:33:14 -05:00
Bhumika Goyal 7d47e9a205 ptp: make ptp_clock_info const
Make these const as they are only used in a copy operation.
Done using Coccinelle.

@match disable optional_qualifier@
identifier s;
@@
static struct ptp_clock_info s = {...};

@ref@
position p;
identifier match.s;
@@
s@p

@good1@
position ref.p;
identifier match.s,f,c;
expression e;
@@
(
e = s@p
|
e = s@p.f
|
c(...,s@p.f,...)
|
c(...,s@p,...)
)

@bad depends on  !good1@
position ref.p;
identifier match.s;
@@
s@p

@depends on forall !bad disable optional_qualifier@
identifier match.s;
@@
static
+ const
struct ptp_clock_info s;

Signed-off-by: Bhumika Goyal <bhumirks@gmail.com>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-22 11:04:51 -07:00
kbuild test robot 49e190ec33 PTP: fix ptr_ret.cocci warnings
drivers/ptp/ptp_kvm.c:229:1-3: WARNING: PTR_ERR_OR_ZERO can be used

 Use PTR_ERR_OR_ZERO rather than if(IS_ERR(...)) + PTR_ERR

Generated by: scripts/coccinelle/api/ptr_ret.cocci

CC: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2017-03-20 16:25:06 +01:00
Radim Krčmář 4306f200c7 ptp_kvm: try to detect hypercall availability
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 <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-02-16 18:42:17 +01:00
Marcelo Tosatti a0e136d436 PTP: add kvm PTP driver
Add a driver with gettime method returning hosts realtime clock.
This allows Chrony to synchronize host and guest clocks with
high precision (see results below).

chronyc> sources
MS Name/IP address         Stratum Poll Reach LastRx Last sample
===============================================================================

To configure Chronyd to use PHC refclock, add the
following line to its configuration file:

refclock PHC /dev/ptpX poll 3 dpoll -2 offset 0

Where /dev/ptpX is the kvmclock PTP clock.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-02-08 17:16:20 +01:00