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path: root/arch/s390/kvm/interrupt.c
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2015-02-09KVM: s390: floating irqs: fix user triggerable endless loopDavid Hildenbrand1-0/+2
If a vm with no VCPUs is created, the injection of a floating irq leads to an endless loop in the kernel. Let's skip the search for a destination VCPU for a floating irq if no VCPUs were created. Reviewed-by: Dominik Dingel <dingel@linux.vnet.ibm.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Cc: stable@vger.kernel.org # v3.15+ Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2015-01-23KVM: s390: remove redundant setting of interrupt typeJens Freimann1-1/+0
Setting inti->type again is unnecessary here, so let's remove this. Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Jens Freimann <jfrei@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2015-01-23KVM: s390: fix bug in interrupt parameter checkJens Freimann1-2/+2
When we convert interrupt data from struct kvm_s390_interrupt to struct kvm_s390_irq we need to check the data in the input parameter not the output parameter. Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com> Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Jens Freimann <jfrei@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2015-01-23KVM: s390: avoid memory leaks if __inject_vm() failsDavid Hildenbrand1-1/+5
We have to delete the allocated interrupt info if __inject_vm() fails. Otherwise user space can keep flooding kvm with floating interrupts and provoke more and more memory leaks. Reported-by: Dominik Dingel <dingel@linux.vnet.ibm.com> Reviewed-by: Dominik Dingel <dingel@linux.vnet.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Cc: stable@vger.kernel.org # v3.15+ Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2015-01-23KVM: s390: trace correct values for set prefix and machine checksJens Freimann1-4/+4
When injecting SIGP set prefix or a machine check, we trace the values in our per-vcpu local_int data structure instead of the parameters passed to the function. Fix this by changing the trace statement to use the correct values. Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Jens Freimann <jfrei@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2015-01-23KVM: s390: fix bug in sigp emergency signal injectionJens Freimann1-3/+2
Currently we are always setting the wrong bit in the bitmap for pending emergency signals. Instead of using emerg.code from the passed in irq parameter, we use the value in our per-vcpu local_int structure, which is always zero. That means all emergency signals will have address 0 as parameter. If two CPUs send a SIGP to the same target, one might be lost. Let's fix this by using the value from the parameter and also trace the correct value. Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Jens Freimann <jfrei@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2015-01-23KVM: s390: no need to hold the kvm->mutex for floating interruptsChristian Borntraeger1-8/+0
The kvm mutex was (probably) used to protect against cpu hotplug. The current code no longer needs to protect against that, as we only rely on CPU data structures that are guaranteed to be available if we can access the CPU. (e.g. vcpu_create will put the cpu in the array AFTER the cpu is ready). Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com> Reviewed-by: Jens Freimann <jfrei@linux.vnet.ibm.com>
2015-01-23KVM: s390: only one external call may be pending at a timeDavid Hildenbrand1-15/+42
Only one external call may be pending at a vcpu at a time. For this reason, we have to detect whether the SIGP externcal call interpretation facility is available. If so, all external calls have to be injected using this mechanism. SIGP EXTERNAL CALL orders have to return whether another external call is already pending. This check was missing until now. SIGP SENSE hasn't returned yet in all conditions whether an external call was pending. If a SIGP EXTERNAL CALL irq is to be injected and one is already pending, -EBUSY is returned. Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2015-01-23KVM: s390: SIGP SET PREFIX cleanupDavid Hildenbrand1-0/+3
This patch cleanes up the the SIGP SET PREFIX code. A SIGP SET PREFIX irq may only be injected if the target vcpu is stopped. Let's move the checking code into the injection code and return -EBUSY if the target vcpu is not stopped. Reviewed-by: Jens Freimann <jfrei@linux.vnet.ibm.com> Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2015-01-23KVM: s390: a VCPU may only stop when no interrupts are left pendingDavid Hildenbrand1-2/+2
As a SIGP STOP is an interrupt with the least priority, it may only result in stop of the vcpu when no other interrupts are left pending. To detect whether a non-stop irq is pending, we need a way to mask out stop irqs from the general kvm_cpu_has_interrupt() function. For this reason, the existing function (with an outdated name) is replaced by kvm_s390_vcpu_has_irq() which allows to mask out pending stop irqs. Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2015-01-23KVM: s390: handle stop irqs without action_bitsDavid Hildenbrand1-26/+45
This patch removes the famous action_bits and moves the handling of SIGP STOP AND STORE STATUS directly into the SIGP STOP interrupt. The new local interrupt infrastructure is used to track pending stop requests. STOP irqs are the only irqs that don't get actively delivered. They remain pending until the stop function is executed (=stop intercept). If another STOP irq is already pending, -EBUSY will now be returned (needed for the SIGP handling code). Migration of pending SIGP STOP (AND STORE STATUS) orders should now be supported out of the box. Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2015-01-23KVM: s390: new parameter for SIGP STOP irqsDavid Hildenbrand1-1/+17
In order to get rid of the action_flags and to properly migrate pending SIGP STOP irqs triggered e.g. by SIGP STOP AND STORE STATUS, we need to remember whether to store the status when stopping. For this reason, a new parameter (flags) for the SIGP STOP irq is introduced. These flags further define details of the requested STOP and can be easily migrated. Reviewed-by: Thomas Huth <thuth@linux.vnet.ibm.com> Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2015-01-23KVM: s390: forward hrtimer if guest ckc not pending yetDavid Hildenbrand1-2/+12
Patch 0759d0681cae ("KVM: s390: cleanup handle_wait by reusing kvm_vcpu_block") changed the way pending guest clock comparator interrupts are detected. It was assumed that as soon as the hrtimer wakes up, the condition for the guest ckc is satisfied. This is however only true as long as adjclock() doesn't speed up the monotonic clock. Reason is that the hrtimer is based on CLOCK_MONOTONIC, the guest clock comparator detection is based on the raw TOD clock. If CLOCK_MONOTONIC runs faster than the TOD clock, the hrtimer wakes the target VCPU up too early and the target VCPU will not detect any pending interrupts, therefore going back to sleep. It will never be woken up again because the hrtimer has finished. The VCPU is stuck. As a quick fix, we have to forward the hrtimer until the guest clock comparator is really due, to guarantee properly timed wake ups. As the hrtimer callback might be triggered on another cpu, we have to make sure that the timer is really stopped and not currently executing the callback on another cpu. This can happen if the vcpu thread is scheduled onto another physical cpu, but the timer base is not migrated. So lets use hrtimer_cancel instead of try_to_cancel. A proper fix might be to introduce a RAW based hrtimer. Reported-by: Christian Borntraeger <borntraeger@de.ibm.com> Cc: stable@vger.kernel.org Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2015-01-23KVM: s390: prevent sleep duration underflows in handle_wait()David Hildenbrand1-1/+7
We sometimes get an underflow for the sleep duration, which most likely won't result in the short sleep time we wanted. So let's check for sleep duration underflows and directly continue to run the guest if we get one. Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2015-01-23KVM: s390: make local function staticChristian Borntraeger1-1/+1
sparse rightfully complains about warning: symbol '__inject_extcall' was not declared. Should it be static? Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2014-12-04KVM: s390: clean up return code handling in irq delivery codeJens Freimann1-13/+13
Instead of returning a possibly random or'ed together value, let's always return -EFAULT if rc is set. Signed-off-by: Jens Freimann <jfrei@linux.vnet.ibm.com> Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2014-12-04KVM: s390: use atomic bitops to access pending_irqs bitmapJens Freimann1-2/+2
Currently we use a mixture of atomic/non-atomic bitops and the local_int spin lock to protect the pending_irqs bitmap and interrupt payload data. We need to use atomic bitops for the pending_irqs bitmap everywhere and in addition acquire the local_int lock where interrupt data needs to be protected. Signed-off-by: Jens Freimann <jfrei@linux.vnet.ibm.com> Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2014-12-04KVM: s390: some ext irqs have to clear the ext cpu addrDavid Hildenbrand1-0/+3
The cpu address of a source cpu (responsible for an external irq) is only to be stored if bit 6 of the ext irq code is set. If bit 6 is not set, it is to be zeroed out. The special external irq code used for virtio and pfault uses the cpu addr as a parameter field. As bit 6 is set, this implementation is correct. Reviewed-by: Thomas Huth <thuth@linux.vnet.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2014-11-28KVM: s390: allow injecting all kinds of machine checksJens Freimann1-3/+11
Allow to specify CR14, logout area, external damage code and failed storage address. Since more then one machine check can be indicated to the guest at a time we need to combine all indication bits with already pending requests. Signed-off-by: Jens Freimann <jfrei@linux.vnet.ibm.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2014-11-28KVM: s390: handle pending local interrupts via bitmapJens Freimann1-245/+356
This patch adapts handling of local interrupts to be more compliant with the z/Architecture Principles of Operation and introduces a data structure which allows more efficient handling of interrupts. * get rid of li->active flag, use bitmap instead * Keep interrupts in a bitmap instead of a list * Deliver interrupts in the order of their priority as defined in the PoP * Use a second bitmap for sigp emergency requests, as a CPU can have one request pending from every other CPU in the system. Signed-off-by: Jens Freimann <jfrei@linux.vnet.ibm.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2014-11-28KVM: s390: refactor interrupt delivery codeJens Freimann1-177/+282
Move delivery code for cpu-local interrupt from the huge do_deliver_interrupt() to smaller functions which handle one type of interrupt. Signed-off-by: Jens Freimann <jfrei@linux.vnet.ibm.com> Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2014-11-28KVM: s390: add defines for virtio and pfault interrupt codeJens Freimann1-2/+4
Get rid of open coded value for virtio and pfault completion interrupts. Signed-off-by: Jens Freimann <jfrei@linux.vnet.ibm.com> Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2014-11-28KVM: s390: external param not valid for cpu timer and ckcDavid Hildenbrand1-4/+2
The 32bit external interrupt parameter is only valid for timing-alert and service-signal interrupts. Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2014-11-28KVM: s390: refactor interrupt injection codeJens Freimann1-54/+167
In preparation for the rework of the local interrupt injection code, factor out injection routines from kvm_s390_inject_vcpu(). Signed-off-by: Jens Freimann <jfrei@linux.vnet.ibm.com> Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2014-11-28KVM: s390: trigger the right CPU exit for floating interruptsChristian Borntraeger1-1/+11
When injecting a floating interrupt and no CPU is idle we kick one CPU to do an external exit. In case of I/O we should trigger an I/O exit instead. This does not matter for Linux guests as external and I/O interrupts are enabled/disabled at the same time, but play safe anyway. The same holds true for machine checks. Since there is no special exit, just reuse the generic stop exit. The injection code inside the VCPU loop will recheck anyway and rearm the proper exits (e.g. control registers) if necessary. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: Thomas Huth <thuth@linux.vnet.ibm.com> Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
2014-10-28KVM: s390: Fix size of monitor-class number fieldThomas Huth1-1/+1
The monitor-class number field is only 16 bits, so we have to use a u16 pointer to access it. Signed-off-by: Thomas Huth <thuth@linux.vnet.ibm.com> Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com> CC: stable@vger.kernel.org # v3.16+ Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2014-10-01KVM: s390: count vcpu wakeups in stat.halt_wakeupDavid Hildenbrand1-0/+1
This patch introduces the halt_wakeup counter used by common code and uses it to count vcpu wakeups done in s390 arch specific code. Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2014-09-10KVM: s390/interrupt: remove double assignmentChristian Borntraeger1-1/+0
r is already initialized to 0. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: Thomas Huth <thuth@linux.vnet.ibm.com>
2014-09-10KVM: s390: unintended fallthrough for external callChristian Borntraeger1-0/+1
We must not fallthrough if the conditions for external call are not met. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: Thomas Huth <thuth@linux.vnet.ibm.com> Cc: stable@vger.kernel.org
2014-09-10KVM: s390: add __must_check to interrupt deliver functionsChristian Borntraeger1-6/+6
We now propagate interrupt injection errors back to the ioctl. We should mark functions that might fail with __must_check. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Acked-by: Jens Freimann <jfrei@linux.vnet.ibm.com>
2014-08-25KVM: s390/mm: cleanup gmap function arguments, variable namesMartin Schwidefsky1-1/+1
Make the order of arguments for the gmap calls more consistent, if the gmap pointer is passed it is always the first argument. In addition distinguish between guest address and user address by naming the variables gaddr for a guest address and vmaddr for a user address. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2014-08-25KVM: s390: don't use kvm lock in interrupt injection codeJens Freimann1-2/+0
The kvm lock protects us against vcpus going away, but they only go away when the virtual machine is shut down. We don't need this mutex here, so let's get rid of it. Signed-off-by: Jens Freimann <jfrei@linux.vnet.ibm.com> Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2014-08-25KVM: s390: return -EFAULT if lowcore is not mapped during irq deliveryJens Freimann1-22/+18
Currently we just kill the userspace process and exit the thread immediatly without making sure that we don't hold any locks etc. Improve this by making KVM_RUN return -EFAULT if the lowcore is not mapped during interrupt delivery. To achieve this we need to pass the return code of guest memory access routines used in interrupt delivery all the way back to the KVM_RUN ioctl. Signed-off-by: Jens Freimann <jfrei@linux.vnet.ibm.com> Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2014-08-25KVM: s390: no special machine check deliveryChristian Borntraeger1-56/+0
The load PSW handler does not have to inject pending machine checks. This can wait until the CPU runs the generic interrupt injection code. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
2014-08-25KVM: s390: factor out get_ilc() functionJens Freimann1-20/+21
Let's make this a reusable function. Signed-off-by: Jens Freimann <jfrei@linux.vnet.ibm.com> Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com> Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2014-08-25KVM: s390: add defines for pfault init delivery codeJens Freimann1-2/+4
Get rid of open coded values for pfault init. Signed-off-by: Jens Freimann <jfrei@linux.vnet.ibm.com> Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2014-08-05KVM: irqchip: Provide and use accessors for irq routing tablePaul Mackerras1-2/+1
This provides accessor functions for the KVM interrupt mappings, in order to reduce the amount of code that accesses the fields of the kvm_irq_routing_table struct, and restrict that code to one file, virt/kvm/irqchip.c. The new functions are kvm_irq_map_gsi(), which maps from a global interrupt number to a set of IRQ routing entries, and kvm_irq_map_chip_pin, which maps from IRQ chip and pin numbers to a global interrupt number. This also moves the update of kvm_irq_routing_table::chip[][] into irqchip.c, out of the various kvm_set_routing_entry implementations. That means that none of the kvm_set_routing_entry implementations need the kvm_irq_routing_table argument anymore, so this removes it. This does not change any locking or data lifetime rules. Signed-off-by: Paul Mackerras <paulus@samba.org> Tested-by: Eric Auger <eric.auger@linaro.org> Tested-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-07-31KVM: s390: rework broken SIGP STOP interrupt handlingDavid Hildenbrand1-0/+3
A VCPU might never stop if it intercepts (for whatever reason) between "fake interrupt delivery" and execution of the stop function. Heart of the problem is that SIGP STOP is an interrupt that has to be processed on every SIE entry until the VCPU finally executes the stop function. This problem was made apparent by commit 7dfc63cf977447e09b1072911c2 (KVM: s390: allow only one SIGP STOP (AND STORE STATUS) at a time). With the old code, the guest could (incorrectly) inject SIGP STOPs multiple times. The bug of losing a sigp stop exists in KVM before 7dfc63cf97, but it was hidden by Linux guests doing a sigp stop loop. The new code (rightfully) returns CC=2 and does not queue a new interrupt. This patch is a simple fix of the problem. Longterm we are going to rework that code - e.g. get rid of the action bits and so on. Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> [some additional patch description]
2014-07-21KVM: s390: remove the tasklet used by the hrtimerDavid Hildenbrand1-12/+1
We can get rid of the tasklet used for waking up a VCPU in the hrtimer code but wakeup the VCPU directly. Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2014-07-21KVM: s390: move vcpu wakeup code to a central pointDavid Hildenbrand1-9/+15
Let's move the vcpu wakeup code to a central point. We should set the vcpu->preempted flag only if the target is actually sleeping and before the real wakeup happens. Otherwise the preempted flag might be set, when not necessary. This may result in immediate reschedules after schedule() in some scenarios. The wakeup code doesn't require the local_int.lock to be held. Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2014-07-21KVM: s390: remove _bh locking from local_int.lockDavid Hildenbrand1-16/+16
local_int.lock is not used in a bottom-half handler anymore, therefore we can turn it into an ordinary spin_lock at all occurrences. Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2014-07-21KVM: s390: cleanup handle_wait by reusing kvm_vcpu_blockDavid Hildenbrand1-36/+5
This patch cleans up the code in handle_wait by reusing the common code function kvm_vcpu_block. signal_pending(), kvm_cpu_has_pending_timer() and kvm_arch_vcpu_runnable() are sufficient for checking if we need to wake-up that VCPU. kvm_vcpu_block uses these functions, so no checks are lost. The flag "timer_due" can be removed - kvm_cpu_has_pending_timer() tests whether the timer is pending, thus the vcpu is correctly woken up. Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2014-05-30KVM: s390: a VCPU is already started when delivering interruptsDavid Hildenbrand1-1/+0
This patch removes the start of a VCPU when delivering a RESTART interrupt. Interrupt delivery is called from kvm_arch_vcpu_ioctl_run. So the VCPU is already considered started - no need to call kvm_s390_vcpu_start. This function will early exit anyway. Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
2014-05-16KVM: s390: interpretive execution of SIGP EXTERNAL CALLDavid Hildenbrand1-4/+26
If the sigp interpretation facility is installed, most SIGP EXTERNAL CALL operations will be interpreted instead of intercepted. A partial execution interception will occurr at the sending cpu only if the target cpu is in the wait state ("W" bit in the cpuflags set). Instruction interception will only happen in error cases (e.g. cpu addr invalid). As a sending cpu might set the external call interrupt pending flags at the target cpu at every point in time, we can't handle this kind of interrupt using our kvm interrupt injection mechanism. The injection will be done automatically by the SIE when preparing the start of the target cpu. Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> CC: Thomas Huth <thuth@linux.vnet.ibm.com> [Adopt external call injection to check for sigp interpretion] Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2014-05-06KVM: s390: Add clock comparator and CPU timer IRQ injectionThomas Huth1-0/+32
Add an interface to inject clock comparator and CPU timer interrupts into the guest. This is needed for handling the external interrupt interception. Signed-off-by: Thomas Huth <thuth@linux.vnet.ibm.com> Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2014-04-29KVM: s390: introduce kvm_s390_vcpu_{start,stop}David Hildenbrand1-1/+1
This patch introduces two new functions to set/clear the CPUSTAT_STOPPED bit and makes use of it at all applicable places. These functions prepare the additional execution of code when starting/stopping a vcpu. The CPUSTAT_STOPPED bit should not be touched outside of these functions. Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2014-04-22KVM: s390: Drop pending interrupts on guest exitChristian Borntraeger1-2/+2
On hard exits (abort, sigkill) we have have some kvm_s390_interrupt_info structures hanging around. Delete those on exit to avoid memory leaks. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> CC: stable@vger.kernel.org Reviewed-by: Thomas Huth <thuth@linux.vnet.ibm.com>
2014-04-22KVM: s390: no timer interrupts when single-stepping a guestDavid Hildenbrand1-0/+3
When a guest is single-stepped, we want to disable timer interrupts. Otherwise, the guest will continuously execute the external interrupt handler and make debugging of code where timer interrupts are enabled almost impossible. The delivery of timer interrupts can be enforced in such sections by setting a breakpoint and continuing execution. In order to disable timer interrupts, they are disabled in the control register of the guest just before SIE entry and are suppressed in the interrupt check/delivery methods. Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2014-04-22KVM: s390: move timer interrupt checks into own functionsDavid Hildenbrand1-18/+20
This patch moves the checks for enabled timer (clock-comparator) interrupts and pending timer interrupts into own functions, making the code better readable and easier to maintain. The method kvm_cpu_has_pending_timer is filled with life. Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2014-04-22KVM: s390: hardware support for guest debuggingDavid Hildenbrand1-1/+7
This patch adds support to debug the guest using the PER facility on s390. Single-stepping, hardware breakpoints and hardware watchpoints are supported. In order to use the PER facility of the guest without it noticing it, the control registers of the guest have to be patched and access to them has to be intercepted(stctl, stctg, lctl, lctlg). All PER program interrupts have to be intercepted and only the relevant PER interrupts for the guest have to be given back. Special care has to be taken about repeated exits on the same hardware breakpoint. The intervention of the host in the guests PER configuration is not fully transparent. PER instruction nullification can not be used by the guest and too many storage alteration events may be reported to the guest (if it is activated for special address ranges only) when the host concurrently debugging it. Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>