Emulate read and write operations to CNTP_TVAL, CNTP_CVAL and CNTP_CTL.
Now VMs are able to use the EL1 physical timer.
Signed-off-by: Jintack Lim <jintack@cs.columbia.edu>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Set a background timer for the EL1 physical timer emulation while VMs
are running, so that VMs get the physical timer interrupts in a timely
manner.
Schedule the background timer on entry to the VM and cancel it on exit.
This would not have any performance impact to the guest OSes that
currently use the virtual timer since the physical timer is always not
enabled.
Signed-off-by: Jintack Lim <jintack@cs.columbia.edu>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
When scheduling a background timer, consider both of the virtual and
physical timer and pick the earliest expiration time.
Signed-off-by: Jintack Lim <jintack@cs.columbia.edu>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Now that we maintain the EL1 physical timer register states of VMs,
update the physical timer interrupt level along with the virtual one.
Signed-off-by: Jintack Lim <jintack@cs.columbia.edu>
Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Now that we have a separate structure for timer context, make functions
generic so that they can work with any timer context, not just the
virtual timer context. This does not change the virtual timer
functionality.
Signed-off-by: Jintack Lim <jintack@cs.columbia.edu>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Make cntvoff per each timer context. This is helpful to abstract kvm
timer functions to work with timer context without considering timer
types (e.g. physical timer or virtual timer).
This also would pave the way for ever doing adjustments of the cntvoff
on a per-CPU basis if that should ever make sense.
Signed-off-by: Jintack Lim <jintack@cs.columbia.edu>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Abstract virtual timer context into a separate structure and change all
callers referring to timer registers, irq state and so on. No change in
functionality.
This is about to become very handy when adding the EL1 physical timer.
Signed-off-by: Jintack Lim <jintack@cs.columbia.edu>
Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
The only benefit of having kvm_vgic_inject_mapped_irq separate from
kvm_vgic_inject_irq is that we pass a boolean that we use for error
checking on the injection path.
While this could potentially help in some aspect of robustness, it's
also a little bit of a defensive move, and arguably callers into the
vgic should have make sure they have marked their virtual IRQs as mapped
if required.
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Current KVM world switch code is unintentionally setting wrong bits to
CNTHCTL_EL2 when E2H == 1, which may allow guest OS to access physical
timer. Bit positions of CNTHCTL_EL2 are changing depending on
HCR_EL2.E2H bit. EL1PCEN and EL1PCTEN are 1st and 0th bits when E2H is
not set, but they are 11th and 10th bits respectively when E2H is set.
In fact, on VHE we only need to set those bits once, not for every world
switch. This is because the host kernel runs in EL2 with HCR_EL2.TGE ==
1, which makes those bits have no effect for the host kernel execution.
So we just set those bits once for guests, and that's it.
Signed-off-by: Jintack Lim <jintack@cs.columbia.edu>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
When a VCPU blocks (WFI) and has programmed the vtimer, we program a
soft timer to expire in the future to wake up the vcpu thread when
appropriate. Because such as wake up involves a vcpu kick, and the
timer expire function can get called from interrupt context, and the
kick may sleep, we have to schedule the kick in the work function.
The work function currently has a warning that gets raised if it turns
out that the timer shouldn't fire when it's run, which was added because
the idea was that in that case the work should never have been cancelled.
However, it turns out that this whole thing is racy and we can get
spurious warnings. The problem is that we clear the armed flag in the
work function, which may run in parallel with the
kvm_timer_unschedule->timer_disarm() call. This results in a possible
situation where the timer_disarm() call does not call
cancel_work_sync(), which effectively synchronizes the completion of the
work function with running the VCPU. As a result, the VCPU thread
proceeds before the work function completees, causing changes to the
timer state such that kvm_timer_should_fire(vcpu) returns false in the
work function.
All we do in the work function is to kick the VCPU, and an occasional
rare extra kick never harmed anyone. Since the race above is extremely
rare, we don't bother checking if the race happens but simply remove the
check and the clearing of the armed flag from the work function.
Reported-by: Matthias Brugger <mbrugger@suse.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Pull timer type cleanups from Thomas Gleixner:
"This series does a tree wide cleanup of types related to
timers/timekeeping.
- Get rid of cycles_t and use a plain u64. The type is not really
helpful and caused more confusion than clarity
- Get rid of the ktime union. The union has become useless as we use
the scalar nanoseconds storage unconditionally now. The 32bit
timespec alike storage got removed due to the Y2038 limitations
some time ago.
That leaves the odd union access around for no reason. Clean it up.
Both changes have been done with coccinelle and a small amount of
manual mopping up"
* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
ktime: Get rid of ktime_equal()
ktime: Cleanup ktime_set() usage
ktime: Get rid of the union
clocksource: Use a plain u64 instead of cycle_t
There is no point in having an extra type for extra confusion. u64 is
unambiguous.
Conversion was done with the following coccinelle script:
@rem@
@@
-typedef u64 cycle_t;
@fix@
typedef cycle_t;
@@
-cycle_t
+u64
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: John Stultz <john.stultz@linaro.org>
When the state names got added a script was used to add the extra argument
to the calls. The script basically converted the state constant to a
string, but the cleanup to convert these strings into meaningful ones did
not happen.
Replace all the useless strings with 'subsys/xxx/yyy:state' strings which
are used in all the other places already.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Link: http://lkml.kernel.org/r/20161221192112.085444152@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
When the arch timer code fails to initialize (for example because the
memory mapped timer doesn't work, which is currently seen with the AEM
model), then KVM just continues happily with a final result that KVM
eventually does a NULL pointer dereference of the uninitialized cycle
counter.
Check directly for this in the init path and give the user a reasonable
error in this case.
Cc: Shih-Wei Li <shihwei@cs.columbia.edu>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
1) Since commit:41a54482 changed timer enabled variable to per-vcpu,
the correlative comment in kvm_timer_enable is useless now.
2) After the kvm module init successfully, the timecounter is always
non-null, so we can remove the checking of timercounter.
Signed-off-by: Longpeng(Mike) <longpeng2@huawei.com>
Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Remove two unnecessary labels now that kvm_timer_hyp_init is not
creating its own workqueue anymore.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
The workqueue "irqfd_cleanup_wq" queues a single work item
&irqfd->shutdown and hence doesn't require ordering. It is a host-wide
workqueue for issuing deferred shutdown requests aggregated from all
vm* instances. It is not being used on a memory reclaim path.
Hence, it has been converted to use system_wq.
The work item has been flushed in kvm_irqfd_release().
The workqueue "wqueue" queues a single work item &timer->expired
and hence doesn't require ordering. Also, it is not being used on
a memory reclaim path. Hence, it has been converted to use system_wq.
System workqueues have been able to handle high level of concurrency
for a long time now and hence it's not required to have a singlethreaded
workqueue just to gain concurrency. Unlike a dedicated per-cpu workqueue
created with create_singlethread_workqueue(), system_wq allows multiple
work items to overlap executions even on the same CPU; however, a
per-cpu workqueue doesn't have any CPU locality or global ordering
guarantee unless the target CPU is explicitly specified and thus the
increase of local concurrency shouldn't make any difference.
Signed-off-by: Bhaktipriya Shridhar <bhaktipriya96@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Similarily to f005bd7e3b ("clocksource/arm_arch_timer: Force
per-CPU interrupt to be level-triggered"), make sure we can
survive an interrupt that has been misconfigured as edge-triggered
by forcing it to be level-triggered (active low is assumed, but
the GIC doesn't really care whether this is high or low).
Hopefully, the amount of shouting in the kernel log will convince
the user to do something about their firmware.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
We are about to modify the VGIC to allocate all data structures
dynamically and store mapped IRQ information on a per-IRQ struct, which
is indeed allocated dynamically at init time.
Therefore, we cannot record the mapped IRQ info from the timer at timer
reset time like it's done now, because VCPU reset happens before timer
init.
A possible later time to do this is on the first run of a per VCPU, it
just requires us to move the enable state to be a per-VCPU state and do
the lookup of the physical IRQ number when we are about to run the VCPU.
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Now that the virtual arch timer does not care about the irq_phys_map
anymore, let's rework kvm_vgic_map_phys_irq() to return an error
value instead. Any reference to that mapping can later be done by
passing the correct combination of VCPU and virtual IRQ number.
This makes the irq_phys_map handling completely private to the
VGIC code.
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Eric Auger <eric.auger@linaro.org>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Now that the interface between the arch timer and the VGIC does not
require passing the irq_phys_map entry pointer anymore, let's remove
it from the virtual arch timer and use the virtual IRQ number instead
directly.
The remaining pointer returned by kvm_vgic_map_phys_irq() will be
removed in the following patch.
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Eric Auger <eric.auger@linaro.org>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
The communication of a Linux IRQ number from outside the VGIC to the
vgic was a leftover from the day when the vgic code cared about how a
particular device injects virtual interrupts mapped to a physical
interrupt.
We can safely remove this notion, leaving all physical IRQ handling to
be done in the device driver (the arch timer in this case), which makes
room for a saner API for the new VGIC.
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Eric Auger <eric.auger@linaro.org>
kvm_vgic_unmap_phys_irq() only needs the virtual IRQ number, so let's
just pass that between the arch timer and the VGIC to get rid of
the irq_phys_map pointer.
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Eric Auger <eric.auger@linaro.org>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Jintack Lim
Christoffer Dall
Linus Torvalds
Thomas Gleixner
Longpeng(Mike)
Paolo Bonzini
Bhaktipriya Shridhar
Marc Zyngier
Richard Cochran
Andre Przywara