Commit Graph

716 Commits

Author SHA1 Message Date
Martin Schwidefsky 6ea427bbbd s390/mm: add reference counter to gmap structure
Let's use a reference counter mechanism to control the lifetime of
gmap structures. This will be needed for further changes related to
gmap shadows.

Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-20 09:53:59 +02:00
Martin Schwidefsky b2d73b2a0a s390/mm: extended gmap pte notifier
The current gmap pte notifier forces a pte into to a read-write state.
If the pte is invalidated the gmap notifier is called to inform KVM
that the mapping will go away.

Extend this approach to allow read-write, read-only and no-access
as possible target states and call the pte notifier for any change
to the pte.

This mechanism is used to temporarily set specific access rights for
a pte without doing the heavy work of a true mprotect call.

Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-20 09:46:49 +02:00
Martin Schwidefsky 414d3b0749 s390/kvm: page table invalidation notifier
Pass an address range to the page table invalidation notifier
for KVM. This allows to notify changes that affect a larger
virtual memory area, e.g. for 1MB pages.

Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-20 09:46:48 +02:00
Paolo Bonzini a03825bbd0 KVM: s390: use kvm->created_vcpus
The new created_vcpus field avoids possible races between enabling
capabilities and creating VCPUs.

Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-06-16 10:07:37 +02:00
Paolo Bonzini f26ed98326 KVM: s390: Features and fixes for 4.8 part1
Four bigger things:
 1. The implementation of the STHYI opcode in the kernel. This is used
    in libraries like qclib [1] to provide enough information for a
    capacity and usage based software licence pricing. The STHYI content
    is defined by the related z/VM documentation [2]. Its data can be
    composed by accessing several other interfaces provided by LPAR or
    the machine. This information is partially sensitive or root-only
    so the kernel does the necessary filtering.
 2. Preparation for nested virtualization (VSIE). KVM should query the
    proper sclp interfaces for the availability of some features before
    using it. In the past we have been sloppy and simply assumed that
    several features are available. With this we should be able to handle
    most cases of a missing feature.
 3. CPU model interfaces extended by some additional features that are
    not covered by a facility bit in STFLE. For example all the crypto
    instructions of the coprocessor provide a query function. As reality
    tends to be more complex (e.g. export regulations might block some
    algorithms) we have to provide additional interfaces to query or
    set these non-stfle features.
 4. Several fixes and changes detected and fixed when doing 1-3.
 
 All features change base s390 code. All relevant patches have an ACK
 from the s390 or component maintainers.
 
 The next pull request for 4.8 (part2) will contain the implementation
 of VSIE.
 
 [1] http://www.ibm.com/developerworks/linux/linux390/qclib.html
 [2] https://www.ibm.com/support/knowledgecenter/SSB27U_6.3.0/com.ibm.zvm.v630.hcpb4/hcpb4sth.htm
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Merge tag 'kvm-s390-next-4.8-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD

KVM: s390: Features and fixes for 4.8 part1

Four bigger things:
1. The implementation of the STHYI opcode in the kernel. This is used
   in libraries like qclib [1] to provide enough information for a
   capacity and usage based software licence pricing. The STHYI content
   is defined by the related z/VM documentation [2]. Its data can be
   composed by accessing several other interfaces provided by LPAR or
   the machine. This information is partially sensitive or root-only
   so the kernel does the necessary filtering.
2. Preparation for nested virtualization (VSIE). KVM should query the
   proper sclp interfaces for the availability of some features before
   using it. In the past we have been sloppy and simply assumed that
   several features are available. With this we should be able to handle
   most cases of a missing feature.
3. CPU model interfaces extended by some additional features that are
   not covered by a facility bit in STFLE. For example all the crypto
   instructions of the coprocessor provide a query function. As reality
   tends to be more complex (e.g. export regulations might block some
   algorithms) we have to provide additional interfaces to query or
   set these non-stfle features.
4. Several fixes and changes detected and fixed when doing 1-3.

All features change base s390 code. All relevant patches have an ACK
from the s390 or component maintainers.

The next pull request for 4.8 (part2) will contain the implementation
of VSIE.

[1] http://www.ibm.com/developerworks/linux/linux390/qclib.html
[2] https://www.ibm.com/support/knowledgecenter/SSB27U_6.3.0/com.ibm.zvm.v630.hcpb4/hcpb4sth.htm
2016-06-15 09:21:46 +02:00
Andrea Gelmini 960cb306e6 KVM: S390: Fix typo
Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-06-14 11:16:27 +02:00
David Hildenbrand a7e19ab55f KVM: s390: handle missing storage-key facility
Without the storage-key facility, SIE won't interpret SSKE, ISKE and
RRBE for us. So let's add proper interception handlers that will be called
if lazy sske cannot be enabled.

Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-10 12:07:31 +02:00
David Hildenbrand 11ddcd41bc KVM: s390: trace and count all skey intercepts
Let's trace and count all skey handling operations, even if lazy skey
handling was already activated. Also, don't enable lazy skey handling if
anything went wrong while enabling skey handling for the SIE.

Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-10 12:07:31 +02:00
David Hildenbrand 695be0e7a2 KVM: s390: pfmf: handle address overflows
In theory, end could always end up being < start, if overflowing to 0.
Although very unlikely for now, let's just fix it.

Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-10 12:07:30 +02:00
David Hildenbrand 1824c723ac KVM: s390: pfmf: support conditional-sske facility
We already indicate that facility but don't implement it in our pfmf
interception handler. Let's add a new storage key handling function for
conditionally setting the guest storage key.

As we will reuse this function later on, let's directly implement returning
the old key via parameter and indicating if any change happened via rc.

Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-10 12:07:30 +02:00
David Hildenbrand 2c26d1d23a KVM: s390: pfmf: take care of amode when setting reg2
Depending on the addressing mode, we must not overwrite bit 0-31 of the
register. In addition, 24 bit and 31 bit have to set certain bits to 0,
which is guaranteed by converting the end address to an effective
address.

Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-10 12:07:29 +02:00
David Hildenbrand 9a68f0af8c KVM: s390: pfmf: MR and MC are ignored without CSSKE
These two bits are simply ignored when the conditional-SSKE facility is
not installed.

Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-10 12:07:29 +02:00
David Hildenbrand 6164a2e90a KVM: s390: pfmf: fix end address calculation
The current calculation is wrong if absolute != real address. Let's just
calculate the start address for 4k frames upfront. Otherwise, the
calculated end address will be wrong, resulting in wrong memory
location/storage keys getting touched.

To keep low-address protection working (using the effective address),
we have to move the check.

Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-10 12:07:28 +02:00
David Hildenbrand fe69eabf8d KVM: s390: storage keys fit into a char
No need to convert the storage key into an unsigned long, the target
function expects a char as argument.

Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-10 12:07:28 +02:00
David Hildenbrand 154c8c19c3 s390/mm: return key via pointer in get_guest_storage_key
Let's just split returning the key and reporting errors. This makes calling
code easier and avoids bugs as happened already.

Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-10 12:07:28 +02:00
Martin Schwidefsky d3ed1ceeac s390/mm: set and get guest storage key mmap locking
Move the mmap semaphore locking out of set_guest_storage_key
and get_guest_storage_key. This makes the two functions more
like the other ptep_xxx operations and allows to avoid repeated
semaphore operations if multiple keys are read or written.

Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-10 12:07:27 +02:00
Christian Borntraeger dcc98ea614 KVM: s390: fixup I/O interrupt traces
We currently have two issues with the I/O  interrupt injection logging:
1. All QEMU versions up to 2.6 have a wrong encoding of device numbers
etc for the I/O interrupt type, so the inject VM_EVENT will have wrong
data. Let's fix this by using the interrupt parameters and not the
interrupt type number.
2. We only log in kvm_s390_inject_vm, but not when coming from
kvm_s390_reinject_io_int or from flic. Let's move the logging to the
common __inject_io function.

We also enhance the logging for delivery to match the data.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
2016-06-10 12:07:26 +02:00
Christian Borntraeger 1bb78d161f KVM: s390: provide logging for diagnose 0x500
We might need to debug some virtio things, so better have diagnose 500
logged.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
2016-06-10 12:07:26 +02:00
David Hildenbrand f597d24eee KVM: s390: turn on tx even without ctx
Constrained transactional execution is an addon of transactional execution.

Let's enable the assist also if only TX is enabled for the guest.

Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-10 12:07:25 +02:00
David Hildenbrand bdab09f3d8 KVM: s390: enable host-protection-interruption only with ESOP
host-protection-interruption control was introduced with ESOP. So let's
enable it only if we have ESOP and add an explanatory comment why
we can live without it.

Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-10 12:07:25 +02:00
David Hildenbrand 09a400e78e KVM: s390: enable ibs only if available
Let's enable interlock-and-broadcast suppression only if the facility is
actually available.

Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-10 12:07:24 +02:00
David Hildenbrand 873b425e4c KVM: s390: enable PFMFI only if available
Let's enable interpretation of PFMFI only if the facility is
actually available. Emulation code still works in case the guest is
offered EDAT-1.

Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-10 12:07:23 +02:00
David Hildenbrand 48ee7d3a7f KVM: s390: enable cei only if available
Let's only enable conditional-external-interruption if the facility is
actually available.

Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-10 12:07:23 +02:00
David Hildenbrand 11ad65b79e KVM: s390: enable ib only if available
Let's enable intervention bypass only if the facility is acutally
available.

Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-10 12:07:22 +02:00
David Hildenbrand efed110446 KVM: s390: handle missing guest-storage-limit-suppression
If guest-storage-limit-suppression is not available, we would for now
have a valid guest address space with size 0. So let's simply set the
origin to 0 and the limit to hamax.

Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-10 12:07:21 +02:00
David Hildenbrand f9cbd9b025 KVM: s390: provide CMMA attributes only if available
Let's not provide the device attribute for cmma enabling and clearing
if the hardware doesn't support it.

This also helps getting rid of the undocumented return value "-EINVAL"
in case CMMA is not available when trying to enable it.

Also properly document the meaning of -EINVAL for CMMA clearing.

Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-10 12:07:20 +02:00
David Hildenbrand c24cc9c8a6 KVM: s390: enable CMMA if the interpration is available
Now that we can detect if collaborative-memory-management interpretation
is available, replace the heuristic by a real hardware detection.

Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-10 12:07:19 +02:00
David Hildenbrand 89b5b4de33 KVM: s390: guestdbg: signal missing hardware support
Without guest-PER enhancement, we can't provide any debugging support.
Therefore act like kernel support is missing.

Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-10 12:07:18 +02:00
David Hildenbrand 76a6dd7241 KVM: s390: handle missing 64-bit-SCAO facility
Without that facility, we may only use scaol. So fallback
to DMA allocation in that case, so we won't overwrite random memory
via the SIE.

Also disallow ESCA, so we don't have to handle that allocation case.

Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-10 12:07:18 +02:00
David Hildenbrand 0a763c780b KVM: s390: interface to query and configure cpu subfunctions
We have certain instructions that indicate available subfunctions via
a query subfunction (crypto functions and ptff), or via a test bit
function (plo).

By exposing these "subfunction blocks" to user space, we allow user space
to
1) query available subfunctions and make sure subfunctions won't get lost
   during migration - e.g. properly indicate them via a CPU model
2) change the subfunctions to be reported to the guest (even adding
   unavailable ones)

This mechanism works just like the way we indicate the stfl(e) list to
user space.

This way, user space could even emulate some subfunctions in QEMU in the
future. If this is ever applicable, we have to make sure later on, that
unsupported subfunctions result in an intercept to QEMU.

Please note that support to indicate them to the guest is still missing
and requires hardware support. Usually, the IBC takes already care of these
subfunctions for migration safety. QEMU should make sure to always set
these bits properly according to the machine generation to be emulated.

Available subfunctions are only valid in combination with STFLE bits
retrieved via KVM_S390_VM_CPU_MACHINE and enabled via
KVM_S390_VM_CPU_PROCESSOR. If the applicable bits are available, the
indicated subfunctions are guaranteed to be correct.

Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-10 12:07:17 +02:00
David Hildenbrand bcfa01d787 KVM: s390: gaccess: convert get_vcpu_asce()
Let's use our new function for preparing translation exceptions.

Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-10 12:07:16 +02:00
David Hildenbrand cde0dcfb5d KVM: s390: gaccess: convert guest_page_range()
Let's use our new function for preparing translation exceptions. As we will
need the correct ar, let's pass that to guest_page_range().

This will also make sure that the guest address is stored in the tec
for applicable excptions.

Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-10 12:07:15 +02:00
David Hildenbrand fbcb7d5157 KVM: s390: gaccess: convert guest_translate_address()
Let's use our new function for preparing translation exceptions.

Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-10 12:07:15 +02:00
David Hildenbrand 3e3c67f6a3 KVM: s390: gaccess: convert kvm_s390_check_low_addr_prot_real()
Let's use our new function for preparing translation exceptions.

Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-10 12:07:15 +02:00
David Hildenbrand d03193de30 KVM: s390: gaccess: function for preparing translation exceptions
Let's provide a function trans_exc() that can be used for handling
preparation of translation exceptions on a central basis. We will use
that function to replace existing code in gaccess.

Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-10 12:07:14 +02:00
David Hildenbrand 6167375b55 KVM: s390: gaccess: store guest address on ALC prot exceptions
Let's pass the effective guest address to get_vcpu_asce(), so we
can properly set the guest address in case we inject an ALC protection
exception.

Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-10 12:07:14 +02:00
David Hildenbrand 22be5a1331 KVM: s390: forward ESOP if available
ESOP guarantees that during a protection exception, bit 61 of real location
168-175 will only be set to 1 if it was because of ALCP or DATP. If the
exception is due to LAP or KCP, the bit will always be set to 0.

The old SOP definition allowed bit 61 to be unpredictable in case of LAP
or KCP in some conditions. So ESOP replaces this unpredictability by
a guarantee.

Therefore, we can directly forward ESOP if it is available on our machine.
We don't have to do anything when ESOP is disabled - the guest will simply
expect unpredictable values. Our guest access functions are already
handling ESOP properly.

Please note that future functionality in KVM will require knowledge about
ESOP being enabled for a guest or not.

Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-10 12:07:13 +02:00
David Hildenbrand 15c9705f0c KVM: s390: interface to query and configure cpu features
For now, we only have an interface to query and configure facilities
indicated via STFL(E). However, we also have features indicated via
SCLP, that have to be indicated to the guest by user space and usually
require KVM support.

This patch allows user space to query and configure available cpu features
for the guest.

Please note that disabling a feature doesn't necessarily mean that it is
completely disabled (e.g. ESOP is mostly handled by the SIE). We will try
our best to disable it.

Most features (e.g. SCLP) can't directly be forwarded, as most of them need
in addition to hardware support, support in KVM. As we later on want to
turn these features in KVM explicitly on/off (to simulate different
behavior), we have to filter all features provided by the hardware and
make them configurable.

Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-10 12:07:13 +02:00
Alexander Yarygin c1778e5157 KVM: s390: Add mnemonic print to kvm_s390_intercept_prog
We have a table of mnemonic names for intercepted program
interruptions, let's print readable name of the interruption in the
kvm_s390_intercept_prog trace event.

Signed-off-by: Alexander Yarygin <yarygin@linux.vnet.ibm.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-10 12:07:13 +02:00
Janosch Frank 7d0a5e6241 KVM: s390: Limit sthyi execution
Store hypervisor information is a valid instruction not only in
supervisor state but also in problem state, i.e. the guest's
userspace. Its execution is not only computational and memory
intensive, but also has to get hold of the ipte lock to write to the
guest's memory.

This lock is not intended to be held often and long, especially not
from the untrusted guest userspace. Therefore we apply rate limiting
of sthyi executions per VM.

Signed-off-by: Janosch Frank <frankja@linux.vnet.ibm.com>
Acked-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-10 12:07:12 +02:00
Janosch Frank 95ca2cb579 KVM: s390: Add sthyi emulation
Store Hypervisor Information is an emulated z/VM instruction that
provides a guest with basic information about the layers it is running
on. This includes information about the cpu configuration of both the
machine and the lpar, as well as their names, machine model and
machine type. This information enables an application to determine the
maximum capacity of CPs and IFLs available to software.

The instruction is available whenever the facility bit 74 is set,
otherwise executing it results in an operation exception.

It is important to check the validity flags in the sections before
using data from any structure member. It is not guaranteed that all
members will be valid on all machines / machine configurations.

Signed-off-by: Janosch Frank <frankja@linux.vnet.ibm.com>
Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-10 12:07:12 +02:00
Janosch Frank a011eeb2a3 KVM: s390: Add operation exception interception handler
This commit introduces code that handles operation exception
interceptions. With this handler we can emulate instructions by using
illegal opcodes.

Signed-off-by: Janosch Frank <frankja@linux.vnet.ibm.com>
Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-10 12:07:11 +02:00
Christian Borntraeger 3491caf275 KVM: halt_polling: provide a way to qualify wakeups during poll
Some wakeups should not be considered a sucessful poll. For example on
s390 I/O interrupts are usually floating, which means that _ALL_ CPUs
would be considered runnable - letting all vCPUs poll all the time for
transactional like workload, even if one vCPU would be enough.
This can result in huge CPU usage for large guests.
This patch lets architectures provide a way to qualify wakeups if they
should be considered a good/bad wakeups in regard to polls.

For s390 the implementation will fence of halt polling for anything but
known good, single vCPU events. The s390 implementation for floating
interrupts does a wakeup for one vCPU, but the interrupt will be delivered
by whatever CPU checks first for a pending interrupt. We prefer the
woken up CPU by marking the poll of this CPU as "good" poll.
This code will also mark several other wakeup reasons like IPI or
expired timers as "good". This will of course also mark some events as
not sucessful. As  KVM on z runs always as a 2nd level hypervisor,
we prefer to not poll, unless we are really sure, though.

This patch successfully limits the CPU usage for cases like uperf 1byte
transactional ping pong workload or wakeup heavy workload like OLTP
while still providing a proper speedup.

This also introduced a new vcpu stat "halt_poll_no_tuning" that marks
wakeups that are considered not good for polling.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Radim Krčmář <rkrcmar@redhat.com> (for an earlier version)
Cc: David Matlack <dmatlack@google.com>
Cc: Wanpeng Li <kernellwp@gmail.com>
[Rename config symbol. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-05-13 17:29:23 +02:00
Alexander Yarygin 60a37709ce KVM: s390: Populate mask of non-hypervisor managed facility bits
When a guest is initializing, KVM provides facility bits that can be
successfully used by the guest. It's done by applying
kvm_s390_fac_list_mask mask on host facility bits stored by the STFLE
instruction. Facility bits can be one of two kinds: it's either a
hypervisor managed bit or non-hypervisor managed.

The hardware provides information which bits need special handling.
Let's automatically passthrough to guests new facility bits, that
don't require hypervisor support.

Signed-off-by: Alexander Yarygin <yarygin@linux.vnet.ibm.com>
Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Reviewed-by: Eric Farman <farman@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-05-09 13:33:59 +02:00
Alexander Yarygin ed8dda0bf7 KVM: s390: Enable all facility bits that are known good for passthrough
Some facility bits are in a range that is defined to be "ok for guests
without any necessary hypervisor changes". Enable those bits.

Signed-off-by: Alexander Yarygin <yarygin@linux.vnet.ibm.com>
Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-05-09 13:33:58 +02:00
David Hildenbrand 053dd2308d KVM: s390: force ibc into valid range
Some hardware variants will round the ibc value up/down themselves,
others will report a validity intercept. Let's always round it up/down.

This patch will also make sure that the ibc is set to 0 in case we don't
have ibc support (lowest_ibc == 0).

Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-05-09 13:33:57 +02:00
David Hildenbrand 9bb0ec0997 KVM: s390: cleanup cpuid handling
We only have one cpuid for all VCPUs, so let's directly use the one in the
cpu model. Also always store it directly as u64, no need for struct cpuid.

Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-05-09 13:33:57 +02:00
David Hildenbrand bd50e8ec8f KVM: s390: enable SRS only if enabled for the guest
If we don't have SIGP SENSE RUNNING STATUS enabled for the guest, let's
not enable interpretation so we can correctly report an invalid order.

Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-05-09 13:33:55 +02:00
David Hildenbrand d6af0b491b KVM: s390: enable PFMFI only if guest has EDAT1
Only enable PFMF interpretation if the necessary facility (EDAT1) is
available, otherwise the pfmf handler in priv.c will inject an exception

Reviewed-by: Dominik Dingel <dingel@linux.vnet.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-05-09 13:33:02 +02:00
David Hildenbrand edc5b05566 KVM: s390: support NQ only if the facility is enabled for the guest
While we can not fully fence of the Nonquiescing Key-Setting facility,
we should as try our best to hide it.

Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-05-04 10:57:39 +02:00