STHYI requires extensive locking in the higher hypervisors and is
very computational/memory expensive. Therefore we cache the retrieved
hypervisor info whose valid period is 1s with mutex to allow concurrent
access. rw semaphore can't benefit here due to cache line bounce.
Signed-off-by: NQingFeng Hao <haoqf@linux.vnet.ibm.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

As we need to support sthyi instruction on LPAR too, move the common code
to kernel part and kvm related code to intercept.c for better reuse.
Signed-off-by: NQingFeng Hao <haoqf@linux.vnet.ibm.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

The machine check information is part of the vsie_page.
Signed-off-by: NDavid Hildenbrand <david@redhat.com>
Message-Id: <20170830160603.5452-4-david@redhat.com>
Reviewed-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: NCornelia Huck <cohuck@redhat.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

Move the real logic that always has to be executed out of the
WARN_ON_ONCE.
Signed-off-by: NDavid Hildenbrand <david@redhat.com>
Message-Id: <20170830160603.5452-3-david@redhat.com>
Reviewed-by: NCornelia Huck <cohuck@redhat.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

Looks like the "overflowing" range check is wrong.

|=======b-------a=======|

addr >= a || addr <= b
Signed-off-by: NDavid Hildenbrand <david@redhat.com>
Message-Id: <20170830160603.5452-2-david@redhat.com>
Reviewed-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: NCornelia Huck <cohuck@redhat.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

Independent of the underlying hardware, kvm will now always handle
SIGP SET ARCHITECTURE as if czam were enabled. Therefore, let's not
only forward that bit but always set it.

While at it, add a comment regarding STHYI.
Signed-off-by: NDavid Hildenbrand <david@redhat.com>
Message-Id: <20170829143108.14703-1-david@redhat.com>
Reviewed-by: NCornelia Huck <cohuck@redhat.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

The STFLE bit 147 indicates whether the ESSA no-DAT operation code is
valid, the bit is not normally provided to the host; the host is
instead provided with an SCLP bit that indicates whether guests can
support the feature.

This patch:
* enables the STFLE bit in the guest if the corresponding SCLP bit is
  present in the host.
* adds support for migrating the no-DAT bit in the PGSTEs
* fixes the software interpretation of the ESSA instruction that is
  used when migrating, both for the new operation code and for the old
  "set stable", as per specifications.
Signed-off-by: NClaudio Imbrenda <imbrenda@linux.vnet.ibm.com>
Reviewed-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Acked-by: NCornelia Huck <cohuck@redhat.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

handle_sthyi() always writes to guest memory if the sthyi function
code is zero in order to fault in the page that later is written to.

However a function code of zero does not necessarily mean that a write
to guest memory happens: if the KVM host is running as a second level
guest under z/VM 6.2 the sthyi instruction is indicated to be
available to the KVM host, however if the instruction is executed it
will always return with a return code that indicates "unsupported
function code".

In such a case handle_sthyi() must not write to guest memory. This
means that the prior write access to fault in the guest page may
result in invalid guest exceptions, and/or invalid data modification.

In order to be architecture compliant simply remove the write_guest()
call.

Given that the guest assumed a write access anyway, this fix does not
qualify for -stable. This just makes sure the sthyi handler is
architecture compliant.

Fixes: 95ca2cb5 ("KVM: s390: Add sthyi emulation")
Reviewed-by: NJanosch Frank <frankja@linux.vnet.ibm.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Reviewed-by: NCornelia Huck <cohuck@redhat.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

Allow for the enablement of MEF and the support for the extended
epoch in SIE and VSIE for the extended guest TOD-Clock.

A new interface is used for getting/setting a guest's extended TOD-Clock
that uses a single ioctl invocation, KVM_S390_VM_TOD_EXT.  Since the
host time is a moving target that might see an epoch switch or STP sync
checks we need an atomic ioctl and cannot use the exisiting two
interfaces. The old method of getting and setting the guest TOD-Clock is
still retained and is used when the old ioctls are called.
Signed-off-by: NCollin L. Walling <walling@linux.vnet.ibm.com>
Reviewed-by: NJanosch Frank <frankja@linux.vnet.ibm.com>
Reviewed-by: NClaudio Imbrenda <imbrenda@linux.vnet.ibm.com>
Reviewed-by: NJason J. Herne <jjherne@linux.vnet.ibm.com>
Reviewed-by: NCornelia Huck <cohuck@redhat.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

kvm has always supported the concept of starting in z/Arch mode so let's
reflect the feature bit to the guest.

Also, we change sigp set architecture to reject any request to change
architecture modes.
Signed-off-by: NJason J. Herne <jjherne@linux.vnet.ibm.com>
Reviewed-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: NCornelia Huck <cohuck@redhat.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

sthyi should only generate a specification exception if the function
code is zero and the response buffer is not on a 4k boundary.

The current code would also test for unknown function codes if the
response buffer, that is currently only defined for function code 0,
is not on a 4k boundary and incorrectly inject a specification
exception instead of returning with condition code 3 and return code 4
(unsupported function code).

Fix this by moving the boundary check.

Fixes: 95ca2cb5 ("KVM: s390: Add sthyi emulation")
Cc: <stable@vger.kernel.org> # 4.8+
Reviewed-by: NJanosch Frank <frankja@linux.vnet.ibm.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Reviewed-by: NDavid Hildenbrand <david@redhat.com>
Reviewed-by: NCornelia Huck <cohuck@redhat.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

The sthyi inline assembly misses register r3 within the clobber
list. The sthyi instruction will always write a return code to
register "R2+1", which in this case would be r3. Due to that we may
have register corruption and see host crashes or data corruption
depending on how gcc decided to allocate and use registers during
compile time.

Fixes: 95ca2cb5 ("KVM: s390: Add sthyi emulation")
Cc: <stable@vger.kernel.org> # 4.8+
Reviewed-by: NJanosch Frank <frankja@linux.vnet.ibm.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Reviewed-by: NDavid Hildenbrand <david@redhat.com>
Reviewed-by: NCornelia Huck <cohuck@redhat.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

This implements kvm_arch_vcpu_in_kernel() for s390.  DIAG is a privileged
operation, so it cannot be called from problem state (user mode).
Signed-off-by: NLongpeng(Mike) <longpeng2@huawei.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

If a vcpu exits due to request a user mode spinlock, then
the spinlock-holder may be preempted in user mode or kernel mode.
(Note that not all architectures trap spin loops in user mode,
only AMD x86 and ARM/ARM64 currently do).

But if a vcpu exits in kernel mode, then the holder must be
preempted in kernel mode, so we should choose a vcpu in kernel mode
as a more likely candidate for the lock holder.

This introduces kvm_arch_vcpu_in_kernel() to decide whether the
vcpu is in kernel-mode when it's preempted.  kvm_vcpu_on_spin's
new argument says the same of the spinning VCPU.
Signed-off-by: NLongpeng(Mike) <longpeng2@huawei.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Acked-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: NJanosch Frank <frankja@linux.vnet.ibm.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

The following warning was triggered by missing srcu locks around
the storage key handling functions.

=============================
WARNING: suspicious RCU usage
4.12.0+ #56 Not tainted
-----------------------------
./include/linux/kvm_host.h:572 suspicious rcu_dereference_check() usage!
rcu_scheduler_active = 2, debug_locks = 1
 1 lock held by live_migration/4936:
  #0:  (&mm->mmap_sem){++++++}, at: [<0000000000141be0>]
kvm_arch_vm_ioctl+0x6b8/0x22d0

 CPU: 8 PID: 4936 Comm: live_migration Not tainted 4.12.0+ #56
 Hardware name: IBM 2964 NC9 704 (LPAR)
 Call Trace:
 ([<000000000011378a>] show_stack+0xea/0xf0)
  [<000000000055cc4c>] dump_stack+0x94/0xd8
  [<000000000012ee70>] gfn_to_memslot+0x1a0/0x1b8
  [<0000000000130b76>] gfn_to_hva+0x2e/0x48
  [<0000000000141c3c>] kvm_arch_vm_ioctl+0x714/0x22d0
  [<000000000013306c>] kvm_vm_ioctl+0x11c/0x7b8
  [<000000000037e2c0>] do_vfs_ioctl+0xa8/0x6c8
  [<000000000037e984>] SyS_ioctl+0xa4/0xb8
  [<00000000008b20a4>] system_call+0xc4/0x27c
 1 lock held by live_migration/4936:
  #0:  (&mm->mmap_sem){++++++}, at: [<0000000000141be0>]
kvm_arch_vm_ioctl+0x6b8/0x22d0
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Pierre Morel<pmorel@linux.vnet.ibm.com>

With vsie feature enabled, kvm can support nested guests (guest-3).
So inject machine check to the guest-2 if it happens when the nested
guest is running. And guest-2 will detect the machine check belongs
to guest-3 and reinject it into guest-3.
The host (guest-1) tries to inject the machine check to the picked
destination vcpu if it's a floating machine check.
Signed-off-by: NQingFeng Hao <haoqf@linux.vnet.ibm.com>
Acked-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

If the exit flag of SIE indicates that a machine check has happened
during guest's running and needs to be injected, inject it to the guest
accordingly.
But some machine checks, e.g. Channel Report Pending (CRW), refer to
host conditions only (the guest's channel devices are not managed by
the kernel directly) and are therefore not injected into the guest.
External Damage (ED) is also not reinjected into the guest because ETR
conditions are gone in Linux and STP conditions are not enabled in the
guest, and ED contains only these 8 ETR and STP conditions.
In general, instruction-processing damage, system recovery,
storage error, service-processor damage and channel subsystem damage
will be reinjected into the guest, and the remain (System damage,
timing-facility damage, warning, ED and CRW) will be handled on the host.
Signed-off-by: NQingFeng Hao <haoqf@linux.vnet.ibm.com>
Acked-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

When a machine check happens in the guest, related mcck info (mcic,
external damage code, ...) is stored in the vcpu's lowcore on the host.
Then the machine check handler's low-level part is executed, followed
by the high-level part.

If the high-level part's execution is interrupted by a new machine check
happening on the same vcpu on the host, the mcck info in the lowcore is
overwritten with the new machine check's data.

If the high-level part's execution is scheduled to a different cpu,
the mcck info in the lowcore is uncertain.

Therefore, for both cases, the further reinjection to the guest will use
the wrong data.
Let's backup the mcck info in the lowcore to the sie page
for further reinjection, so that the right data will be used.

Add new member into struct sie_page to store related machine check's
info of mcic, failing storage address and external damage code.
Signed-off-by: NQingFeng Hao <haoqf@linux.vnet.ibm.com>
Acked-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

For real-space designation asces the asce origin part is only a token.
The asce token origin must not be used to generate an effective
address for storage references. This however is erroneously done
within kvm_s390_shadow_tables().

Furthermore within the same function the wrong parts of virtual
addresses are used to generate a corresponding real address
(e.g. the region second index is used as region first index).

Both of the above can result in incorrect address translations. Only
for real space designations with a token origin of zero and addresses
below one megabyte the translation was correct.

Furthermore replace a "!asce.r" statement with a "!*fake" statement to
make it more obvious that a specific condition has nothing to do with
the architecture, but with the fake handling of real space designations.

Fixes: 3218f709 ("s390/mm: support real-space for gmap shadows")
Cc: David Hildenbrand <david@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Reviewed-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

For naturally aligned and sized data structures avoid superfluous
packed and aligned attributes.
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
Reviewed-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

In some cases, userspace needs to get or set all ais states for example
migration. So we introduce a new group KVM_DEV_FLIC_AISM_ALL to provide
interfaces to get or set the adapter-interruption-suppression mode for
all ISCs. The corresponding documentation is updated.
Signed-off-by: NYi Min Zhao <zyimin@linux.vnet.ibm.com>
Reviewed-by: NHalil Pasic <pasic@linux.vnet.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

ifetch

While currently only used to fetch the original instruction on failure
for getting the instruction length code, we should make the page table
walking code future proof.
Suggested-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

* Add the struct used in the ioctls to get and set CMMA attributes.
* Add the two functions needed to get and set the CMMA attributes for
  guest pages.
* Add the two ioctls that use the aforementioned functions.
Signed-off-by: NClaudio Imbrenda <imbrenda@linux.vnet.ibm.com>
Acked-by: NCornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

* Add a migration state bitmap to keep track of which pages have dirty
  CMMA information.
* Disable CMMA by default, so we can track if it's used or not. Enable
  it on first use like we do for storage keys (unless we are doing a
  migration).
* Creates a VM attribute to enter and leave migration mode.
* In migration mode, CMMA is disabled in the SIE block, so ESSA is
  always interpreted and emulated in software.
* Free the migration state on VM destroy.
Signed-off-by: NClaudio Imbrenda <imbrenda@linux.vnet.ibm.com>
Acked-by: NCornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

Rename a couple of the struct psw_bits members so it is more obvious
for what they are good. Initially I thought using the single character
names from the PoP would be sufficient and obvious, but admittedly
that is not true.

The current implementation is not easy to use, if one has to look into
the source file to figure out which member represents the 'per' bit
(which is the 'r' member).

Therefore rename the members to sane names that are identical to the
uapi psw mask defines:

r -> per
i -> io
e -> ext
t -> dat
m -> mcheck
w -> wait
p -> pstate
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

The address space enums that must be used when modifying the address
space part of a psw with the psw_bits() macro can easily be confused
with the psw defines that are used to mask and compare directly the
mask part of a psw.
We have e.g. PSW_AS_PRIMARY vs PSW_ASC_PRIMARY.

To avoid confusion rename the PSW_AS_* enums to PSW_BITS_AS_*.

In addition also rename the PSW_AMODE_* enums, so they also follow the
same naming scheme: PSW_BITS_AMODE_*.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

A first step in vcpu->requests encapsulation.  Additionally, we now
use READ_ONCE() when accessing vcpu->requests, which ensures we
always load vcpu->requests when it's accessed.  This is important as
other threads can change it any time.  Also, READ_ONCE() documents
that vcpu->requests is used with other threads, likely requiring
memory barriers, which it does.
Signed-off-by: NRadim Krčmář <rkrcmar@redhat.com>
[ Documented the new use of READ_ONCE() and converted another check
  in arch/mips/kvm/vz.c ]
Signed-off-by: NAndrew Jones <drjones@redhat.com>
Acked-by: NChristoffer Dall <cdall@linaro.org>
Signed-off-by: NChristoffer Dall <cdall@linaro.org>

If ais is disabled via cpumodel, we must act accordingly, even if
KVM_CAP_S390_AIS was enabled.
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: NPierre Morel <pmorel@linux.vnet.ibm.com>
Reviewed-by: NYi Min Zhao <zyimin@linux.vnet.ibm.com>
Reviewed-by: NHalil Pasic <pasic@linux.vnet.ibm.com>
Reviewed-by: NEric Farman <farman@linux.vnet.ibm.com>

There are many code paths opencoding kvmalloc.  Let's use the helper
instead.  The main difference to kvmalloc is that those users are
usually not considering all the aspects of the memory allocator.  E.g.
allocation requests <= 32kB (with 4kB pages) are basically never failing
and invoke OOM killer to satisfy the allocation.  This sounds too
disruptive for something that has a reasonable fallback - the vmalloc.
On the other hand those requests might fallback to vmalloc even when the
memory allocator would succeed after several more reclaim/compaction
attempts previously.  There is no guarantee something like that happens
though.

This patch converts many of those places to kv[mz]alloc* helpers because
they are more conservative.

Link: http://lkml.kernel.org/r/20170306103327.2766-2-mhocko@kernel.orgSigned-off-by: NMichal Hocko <mhocko@suse.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> # Xen bits
Acked-by: NKees Cook <keescook@chromium.org>
Acked-by: NVlastimil Babka <vbabka@suse.cz>
Acked-by: Andreas Dilger <andreas.dilger@intel.com> # Lustre
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> # KVM/s390
Acked-by: Dan Williams <dan.j.williams@intel.com> # nvdim
Acked-by: David Sterba <dsterba@suse.com> # btrfs
Acked-by: Ilya Dryomov <idryomov@gmail.com> # Ceph
Acked-by: Tariq Toukan <tariqt@mellanox.com> # mlx4
Acked-by: Leon Romanovsky <leonro@mellanox.com> # mlx5
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Anton Vorontsov <anton@enomsg.org>
Cc: Colin Cross <ccross@android.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Ben Skeggs <bskeggs@redhat.com>
Cc: Kent Overstreet <kent.overstreet@gmail.com>
Cc: Santosh Raspatur <santosh@chelsio.com>
Cc: Hariprasad S <hariprasad@chelsio.com>
Cc: Yishai Hadas <yishaih@mellanox.com>
Cc: Oleg Drokin <oleg.drokin@intel.com>
Cc: "Yan, Zheng" <zyan@redhat.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Users were expected to use kvm_check_request() for testing and clearing,
but request have expanded their use since then and some users want to
only test or do a faster clear.

Make sure that requests are not directly accessed with bit operations.
Reviewed-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: NRadim Krčmář <rkrcmar@redhat.com>
Reviewed-by: NAndrew Jones <drjones@redhat.com>
Reviewed-by: NCornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

msa6 and msa7 require no changes.
msa8 adds kma instruction and feature area.
Signed-off-by: NJason J. Herne <jjherne@linux.vnet.ibm.com>
Reviewed-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

The PPNO (Perform Pseudorandom Number Operation) instruction
has been renamed to PRNO (Perform Random Number Operation).
To avoid confusion and conflicts with future extensions with
this instruction (like e.g. provide a true random number
generator) this patch renames all occurences in cpacf.h and
adjusts the only exploiter code which is the prng device
driver and one line in the s390 kvm feature check.
Signed-off-by: NHarald Freudenberger <freude@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

The TASK_SIZE for a process should be maximum possible size of the address
space, 2GB for a 31-bit process and 8PB for a 64-bit process. The number
of page table levels required for a given memory layout is a consequence
of the mapped memory areas and their location.
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

If the KSS facility is available on the machine, we also make it
available for our KVM guests.

The KSS facility bypasses storage key management as long as the guest
does not issue a related instruction. When that happens, the control is
returned to the host, which has to turn off KSS for a guest vcpu
before retrying the instruction.
Signed-off-by: NCorey S. McQuay <csmcquay@linux.vnet.ibm.com>
Signed-off-by: NFarhan Ali <alifm@linux.vnet.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

When delivering a machine check the CPU state is "loaded", which
means that some registers are already in the host registers.
Before writing the register content into the machine check
save area, we must make sure that we save the content of the
registers into the data structures that are used for delivering
the machine check.
We already do the right thing for access, vector/floating point
registers, let's do the same for guarded storage.

Fixes: 4e0b1ab7 ("KVM: s390: gs support for kvm guests")
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: NCornelia Huck <cornelia.huck@de.ibm.com>

If the guest does not use the host register management, but it uses
the sdnx area, we must fill in a proper sdnxo value (address of sdnx
and the sdnxc).
Reported-by: NDavid Hildenbrand <david@redhat.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Acked-by: NCornelia Huck <cornelia.huck@de.ibm.com>

Introduce a cap to enable AIS facility bit, and add documentation
for this capability.
Signed-off-by: NYi Min Zhao <zyimin@linux.vnet.ibm.com>
Signed-off-by: NFei Li <sherrylf@linux.vnet.ibm.com>
Reviewed-by: NCornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

Inject adapter interrupts on a specified adapter which allows to
retrieve the adapter flags, e.g. if the adapter is subject to AIS
facility or not. And add documentation for this interface.

For adapters subject to AIS, handle the airq injection suppression
for a given ISC according to the interruption mode:
- before injection, if NO-Interruptions Mode, just return 0 and
  suppress, otherwise, allow the injection.
- after injection, if SINGLE-Interruption Mode, change it to
  NO-Interruptions Mode to suppress the following interrupts.

Besides, add tracepoint for suppressed airq and AIS mode transitions.
Signed-off-by: NYi Min Zhao <zyimin@linux.vnet.ibm.com>
Signed-off-by: NFei Li <sherrylf@linux.vnet.ibm.com>
Reviewed-by: NCornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

Provide an interface for userspace to modify AIS
(adapter-interruption-suppression) mode state, and add documentation
for the interface. Allowed target modes are ALL-Interruptions mode
and SINGLE-Interruption mode.

We introduce the 'simm' and 'nimm' fields in kvm_s390_float_interrupt
to store interruption modes for each ISC. Each bit in 'simm' and
'nimm' targets to one ISC, and collaboratively indicate three modes:
ALL-Interruptions, SINGLE-Interruption and NO-Interruptions. This
interface can initiate most transitions between the states; transition
from SINGLE-Interruption to NO-Interruptions via adapter interrupt
injection will be introduced in a following patch. The meaningful
combinations are as follows:

    interruption mode | simm bit | nimm bit
    ------------------|----------|----------
             ALL      |    0     |     0
           SINGLE     |    1     |     0
             NO       |    1     |     1

Besides, add tracepoint to track AIS mode transitions.
Co-Authored-By: NYi Min Zhao <zyimin@linux.vnet.ibm.com>
Signed-off-by: NYi Min Zhao <zyimin@linux.vnet.ibm.com>
Signed-off-by: NFei Li <sherrylf@linux.vnet.ibm.com>
Reviewed-by: NCornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>