SPX (SET PREFIX)  and SIGP (Set prefix) can change the prefix
register of a CPU. As sigp set prefix may be handled in user
space (KVM_CAP_S390_USER_SIGP), we would not log the changes
triggered via SIGP in that case. Let's have just one VCPU_EVENT
at the central location that tracks prefix changes.
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: NCornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: NDavid Hildenbrand <dahi@linux.vnet.ibm.com>

As we already only enable CMMA when userspace requests it, we can
safely move the additional checks to the request handler and avoid
doing them multiple times. This also tells userspace if CMMA is
available.
Signed-off-by: NDominik Dingel <dingel@linux.vnet.ibm.com>
Reviewed-by: NDavid Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

Some updates to the control blocks need to be done in a way that
ensures that no CPU is within SIE. Provide wrappers around the
s390_vcpu_block functions and adopt the TOD migration code to
update in a guaranteed fashion. Also rename these functions to
have the kvm_s390_ prefix as everything else.
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: NDavid Hildenbrand <dahi@linux.vnet.ibm.com>

exit_sie_sync is used to kick CPUs out of SIE and prevent reentering at
any point in time. This is used to reload the prefix pages and to
set the IBS stuff in a way that guarantees that after this function
returns we are no longer in SIE. All current users trigger KVM requests.

The request must be set before we block the CPUs to avoid races. Let's
make this implicit by adding the request into a new function
kvm_s390_sync_requests that replaces exit_sie_sync and split out
s390_vcpu_block and s390_vcpu_unblock, that can be used to keep
CPUs out of SIE independent of requests.
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: NDavid Hildenbrand <dahi@linux.vnet.ibm.com>
Reviewed-by: NCornelia Huck <cornelia.huck@de.ibm.com>

This patch adds support to migrate vcpu interrupts. Two new vcpu ioctls
are added which get/set the complete status of pending interrupts in one
go. The ioctls are marked as available with the new capability
KVM_CAP_S390_IRQ_STATE.

We can not use a ONEREG, as the number of pending local interrupts is not
constant and depends on the number of CPUs.

To retrieve the interrupt state we add an ioctl KVM_S390_GET_IRQ_STATE.
Its input parameter is a pointer to a struct kvm_s390_irq_state which
has a buffer and length.  For all currently pending interrupts, we copy
a struct kvm_s390_irq into the buffer and pass it to userspace.

To store interrupt state into a buffer provided by userspace, we add an
ioctl KVM_S390_SET_IRQ_STATE. It passes a struct kvm_s390_irq_state into
the kernel and injects all interrupts contained in the buffer.
Signed-off-by: NJens Freimann <jfrei@linux.vnet.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Acked-by: NCornelia Huck <cornelia.huck@de.ibm.com>

This patch makes interrupt handling compliant to the z/Architecture
Principles of Operation with regard to interrupt priorities.

Add a bitmap for pending floating interrupts. Each bit relates to a
interrupt type and its list. A turned on bit indicates that a list
contains items (interrupts) which need to be delivered.  When delivering
interrupts on a cpu we can merge the existing bitmap for cpu-local
interrupts and floating interrupts and have a single mechanism for
delivery.
Currently we have one list for all kinds of floating interrupts and a
corresponding spin lock. This patch adds a separate list per
interrupt type. An exception to this are service signal and machine check
interrupts, as there can be only one pending interrupt at a time.
Signed-off-by: NJens Freimann <jfrei@linux.vnet.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Acked-by: NCornelia Huck <cornelia.huck@de.ibm.com>

The patch represents capability KVM_CAP_S390_VECTOR_REGISTERS by means
of the SIMD facility bit. This allows to a) disable the use of SIMD when
used in conjunction with a not-SIMD-aware QEMU, b) to enable SIMD when
used with a SIMD-aware version of QEMU and c) finally by means of a QEMU
version using the future cpu model ioctls.
Signed-off-by: NMichael Mueller <mimu@linux.vnet.ibm.com>
Reviewed-by: NEric Farman <farman@linux.vnet.ibm.com>
Tested-by: NEric Farman <farman@linux.vnet.ibm.com>
Reviewed-by: NDavid Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

In access register mode, the write_guest() read_guest() and other
functions will invoke the access register translation, which
requires an ar, designated by one of the instruction fields.
Signed-off-by: NAlexander Yarygin <yarygin@linux.vnet.ibm.com>
Reviewed-by: NThomas Huth <thuth@linux.vnet.ibm.com>
Acked-by: NCornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Message-Id: <1425932832-6244-1-git-send-email-geert+renesas@glider.be>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

Store additional status in the machine check handler, in order to
collect status (such as vector registers) that is not defined by
store status.
Signed-off-by: NEric Farman <farman@linux.vnet.ibm.com>
Reviewed-by: NThomas Huth <thuth@linux.vnet.ibm.com>
Reviewed-by: NDavid Hildenbrand <dahi@linux.vnet.ibm.com>
Reviewed-by: NCornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

The reinjection of an I/O interrupt can fail if the list is at the limit
and between the dequeue and the reinjection, another I/O interrupt is
injected (e.g. if user space floods kvm with I/O interrupts).

This patch avoids this memory leak and returns -EFAULT in this special
case. This error is not recoverable, so let's fail hard. This can later
be avoided by not dequeuing the interrupt but working directly on the
locked list.
Signed-off-by: NDavid Hildenbrand <dahi@linux.vnet.ibm.com>
Cc: stable@vger.kernel.org # 3.16+
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

Most facility related decisions in KVM have to take into account:

- the facilities offered by the underlying run container (LPAR/VM)
- the facilities supported by the KVM code itself
- the facilities requested by a guest VM

This patch adds the KVM driver requested facilities to the test routine.

It additionally renames struct s390_model_fac to kvm_s390_fac and its field
names to be more meaningful.

The semantics of the facilities stored in the KVM architecture structure
is changed. The address arch.model.fac->list now points to the guest
facility list and arch.model.fac->mask points to the KVM facility mask.

This patch fixes the behaviour of KVM for some facilities for guests
that ignore the guest visible facility bits, e.g. guests could use
transactional memory intructions on hosts supporting them even if the
chosen cpu model would not offer them.

The userspace interface is not affected by this change.
Signed-off-by: NMichael Mueller <mimu@linux.vnet.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

The patch introduces facilities and cpu_ids per virtual machine.
Different virtual machines may want to expose different facilities and
cpu ids to the guest, so let's make them per-vm instead of global.
Signed-off-by: NMichael Mueller <mimu@linux.vnet.ibm.com>
Reviewed-by: NCornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: NDavid Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

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: NCornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: NDavid Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

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: NCornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: NDavid Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

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: NDavid Hildenbrand <dahi@linux.vnet.ibm.com>
Acked-by: NCornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

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: NJens Freimann <jfrei@linux.vnet.ibm.com>
Reviewed-by: NCornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: NDavid Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

A couple of our interception handlers rewind the PSW to the beginning
of the instruction to run the intercepted instruction again during the
next SIE entry. This normally works fine, but there is also the
possibility that the instruction did not get run directly but via an
EXECUTE instruction.
In this case, the PSW does not point to the instruction that caused the
interception, but to the EXECUTE instruction! So we've got to rewind the
PSW to the beginning of the EXECUTE instruction instead.
This is now accomplished with a new helper function kvm_s390_rewind_psw().
Signed-off-by: NThomas Huth <thuth@linux.vnet.ibm.com>
Reviewed-by: NDavid Hildenbrand <dahi@linux.vnet.ibm.com>
Reviewed-by: NCornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

Using the new kvm_register_device_ops() interface makes us get rid of
an #ifdef in common code.

Cc: Gleb Natapov <gleb@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NCornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

We now propagate interrupt injection errors back to the ioctl. We
should mark functions that might fail with __must_check.
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Acked-by: NJens Freimann <jfrei@linux.vnet.ibm.com>

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: NJens Freimann <jfrei@linux.vnet.ibm.com>
Reviewed-by: NDavid Hildenbrand <dahi@linux.vnet.ibm.com>
Reviewed-by: NCornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

Use the KVM_REQ_TLB_FLUSH request in order to trigger tlb flushes instead
of manipulating the SIE control block whenever we need it. Also trigger it for
a control register sync directly instead of (ab)using kvm_s390_set_prefix().
Signed-off-by: NDavid Hildenbrand <dahi@linux.vnet.ibm.com>
Reviewed-by: NCornelia Huck <cornelia.huck@de.ibm.com>
Acked-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

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: NChristian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: NCornelia Huck <cornelia.huck@de.ibm.com>

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: NDavid Hildenbrand <dahi@linux.vnet.ibm.com>
Reviewed-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Acked-by: NCornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

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: NDavid Hildenbrand <dahi@linux.vnet.ibm.com>
Reviewed-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Acked-by: NCornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

This patch
- adds s390 specific MP states to linux headers and documents them
- implements the KVM_{SET,GET}_MP_STATE ioctls
- enables KVM_CAP_MP_STATE
- allows user space to control the VCPU state on s390.

If user space sets the VCPU state using the ioctl KVM_SET_MP_STATE, we can disable
manual changing of the VCPU state and trust user space to do the right thing.
Signed-off-by: NDavid Hildenbrand <dahi@linux.vnet.ibm.com>
Reviewed-by: NCornelia Huck <cornelia.huck@de.ibm.com>
Acked-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

The function "__cpu_is_stopped" is not used any more. Let's remove it and
expose the function "is_vcpu_stopped" instead, which is actually what we want.

This patch also converts an open coded check for CPUSTAT_STOPPED to
is_vcpu_stopped().
Signed-off-by: NDavid Hildenbrand <dahi@linux.vnet.ibm.com>
Reviewed-by: NCornelia Huck <cornelia.huck@de.ibm.com>
Acked-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

This patch splits the SIE state guest prefix at offset 4
into a prefix bit field. Additionally it provides the
access functions:

 - kvm_s390_get_prefix()
 - kvm_s390_set_prefix()

to access the prefix per vcpu.
Signed-off-by: NMichael Mueller <mimu@linux.vnet.ibm.com>
Reviewed-by: NCornelia Huck <cornelia.huck@de.ibm.com>
Acked-by: NChristian Borntraeger <borntraeger@de.ibm.com>

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: NDavid Hildenbrand <dahi@linux.vnet.ibm.com>
Reviewed-by: NCornelia 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: NChristian Borntraeger <borntraeger@de.ibm.com>

Rework the function kvm_arch_fault_in_sync() to become a proper helper
function for faulting-in a guest page. Now it takes the guest address as
a parameter and does not ignore the possible error code from gmap_fault()
anymore (which could cause undetected error conditions before).
Signed-off-by: NThomas Huth <thuth@linux.vnet.ibm.com>
Reviewed-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: NCornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

As a program status word is also invalid (and thus generates an
specification exception) if the instruction address is not even,
we should test this in is_valid_psw(), too. This patch also exports
the function so that it becomes available for other parts of the
S390 KVM code as well.
Signed-off-by: NThomas Huth <thuth@linux.vnet.ibm.com>
Reviewed-by: NCornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

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: NDavid Hildenbrand <dahi@linux.vnet.ibm.com>
Reviewed-by: NCornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

The generically assembled low core labels already contain the
address for the TDB.
Signed-off-by: NMichael Mueller <mimu@linux.vnet.ibm.com>
Acked-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: NCornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

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: NChristian Borntraeger <borntraeger@de.ibm.com>
CC: stable@vger.kernel.org
Reviewed-by: NThomas Huth <thuth@linux.vnet.ibm.com>

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: NDavid Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

Introduce the methods to emulate the stctl and stctg instruction. Added tracing
code.
Signed-off-by: NDavid Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

The tpi instruction should be suppressed on addressing and protection
exceptions, so we need to re-inject the dequeued io interrupt in that
case.
Signed-off-by: NCornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

Add a 'struct kvm_s390_pgm_info pgm' member to kvm_vcpu_arch. This
structure will be used if during instruction emulation in the context
of a vcpu exception data needs to be stored somewhere.

Also add a helper function kvm_s390_inject_prog_cond() which can inject
vcpu's last exception if needed.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Reviewed-by: NCornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

Make test_vfacility() available for other files. This is needed for the
new guest access functions, which test if certain facilities are available
for a guest.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Reviewed-by: NCornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

Add a new data structure and function that allows to inject
all kinds of interrupt as defined in the PoP
Signed-off-by: NJens Freimann <jfrei@linux.vnet.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>