Commit Graph

4601 Commits

Author SHA1 Message Date
David Hildenbrand
a3508fbe9d KVM: s390: vsie: initial support for nested virtualization
This patch adds basic support for nested virtualization on s390x, called
VSIE (virtual SIE) and allows it to be used by the guest if the necessary
facilities are supported by the hardware and enabled for the guest.

In order to make this work, we have to shadow the sie control block
provided by guest 2. In order to gain some performance, we have to
reuse the same shadow blocks as good as possible. For now, we allow
as many shadow blocks as we have VCPUs (that way, every VCPU can run the
VSIE concurrently).

We have to watch out for the prefix getting unmapped out of our shadow
gmap and properly get the VCPU out of VSIE in that case, to fault the
prefix pages back in. We use the PROG_REQUEST bit for that purpose.

This patch is based on an initial prototype by Tobias Elpelt.

Acked-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>
2016-06-21 09:43:33 +02:00
David Hildenbrand
3d84683bd7 s390: introduce page_to_virt() and pfn_to_virt()
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Acked-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>
2016-06-20 09:55:32 +02:00
David Hildenbrand
37d9df98b7 KVM: s390: backup the currently enabled gmap when scheduled out
Nested virtualization will have to enable own gmaps. Current code
would enable the wrong gmap whenever scheduled out and back in,
therefore resulting in the wrong gmap being enabled.

This patch reenables the last enabled gmap, therefore avoiding having to
touch vcpu->arch.gmap when enabling a different gmap.

Acked-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>
2016-06-20 09:55:24 +02:00
David Hildenbrand
65d0b0d4bc KVM: s390: fast path for shadow gmaps in gmap notifier
The default kvm gmap notifier doesn't have to handle shadow gmaps.
So let's just directly exit in case we get notified about one.

Acked-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>
2016-06-20 09:55:21 +02:00
David Hildenbrand
01f719176f s390/mm: don't fault everything in read-write in gmap_pte_op_fixup()
Let's not fault in everything in read-write but limit it to read-only
where possible.

When restricting access rights, we already have the required protection
level in our hands. When reading from guest 2 storage (gmap_read_table),
it is obviously PROT_READ. When shadowing a pte, the required protection
level is given via the guest 2 provided pte.

Based on an initial patch by Martin Schwidefsky.

Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-20 09:55:20 +02:00
David Hildenbrand
5b6c963bce s390/mm: allow to check if a gmap shadow is valid
It will be very helpful to have a mechanism to check without any locks
if a given gmap shadow is still valid and matches the given properties.

Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-20 09:55:16 +02:00
David Hildenbrand
4a49443924 s390/mm: remember the int code for the last gmap fault
For nested virtualization, we want to know if we are handling a protection
exception, because these can directly be forwarded to the guest without
additional checks.

Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-20 09:55:08 +02:00
David Hildenbrand
717c05554a s390/mm: limit number of real-space gmap shadows
We have no known user of real-space designation and only support it to
be architecture compliant.

Gmap shadows with real-space designation are never unshadowed
automatically, as there is nothing to protect for the top level table.

So let's simply limit the number of such shadows to one by removing
existing ones on creation of another one.

Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-20 09:55:07 +02:00
David Hildenbrand
3218f7094b s390/mm: support real-space for gmap shadows
We can easily support real-space designation just like EDAT1 and EDAT2.
So guest2 can provide for guest3 an asce with the real-space control being
set.

We simply have to allocate the biggest page table possible and fake all
levels.

There is no protection to consider. If we exceed guest memory, vsie code
will inject an addressing exception (via program intercept). In the future,
we could limit the fake table level to the gmap page table.

As the top level page table can never go away, such gmap shadows will never
get unshadowed, we'll have to come up with another way to limit the number
of kept gmap shadows.

Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-20 09:55:02 +02:00
David Hildenbrand
1c65781b56 s390/mm: push rte protection down to shadow pte
Just like we already do with ste protection, let's take rte protection
into account. This way, the host pte doesn't have to be mapped writable.

Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-20 09:55:00 +02:00
David Hildenbrand
18b8980988 s390/mm: support EDAT2 for gmap shadows
If the guest is enabled for EDAT2, we can easily create shadows for
guest2 -> guest3 provided tables that make use of EDAT2.

If guest2 references a 2GB page, this memory looks consecutive for guest2,
but it does not have to be so for us. Therefore we have to create fake
segment and page tables.

This works just like EDAT1 support, so page tables are removed when the
parent table (r3t table entry) is changed.

We don't hve to care about:
- ACCF-Validity Control in RTTE
- Access-Control Bits in RTTE
- Fetch-Protection Bit in RTTE
- Common-Region Bit in RTTE

Just like for EDAT1, all bits might be dropped and there is no guaranteed
that they are active.

Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-20 09:54:56 +02:00
David Hildenbrand
fd8d4e3ab6 s390/mm: support EDAT1 for gmap shadows
If the guest is enabled for EDAT1, we can easily create shadows for
guest2 -> guest3 provided tables that make use of EDAT1.

If guest2 references a 1MB page, this memory looks consecutive for guest2,
but it might not be so for us. Therefore we have to create fake page tables.

We can easily add that to our existing infrastructure. The invalidation
mechanism will make sure that fake page tables are removed when the parent
table (sgt table entry) is changed.

As EDAT1 also introduced protection on all page table levels, we have to
also shadow these correctly.

We don't have to care about:
- ACCF-Validity Control in STE
- Access-Control Bits in STE
- Fetch-Protection Bit in STE
- Common-Segment Bit in STE

As all bits might be dropped and there is no guaranteed that they are
active ("unpredictable whether the CPU uses these bits", "may be used").
Without using EDAT1 in the shadow ourselfes (STE-format control == 0),
simply shadowing these bits would not be enough. They would be ignored.

Please note that we are using the "fake" flag to make this look consistent
with further changes (EDAT2, real-space designation support) and don't let
the shadow functions handle fc=1 stes.

In the future, with huge pages in the host, gmap_shadow_pgt() could simply
try to map a huge host page if "fake" is set to one and indicate via return
value that no lower fake tables / shadow ptes are required.

Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-20 09:54:51 +02:00
David Hildenbrand
5b062bd494 s390/mm: prepare for EDAT1/EDAT2 support in gmap shadow
In preparation for EDAT1/EDAT2 support for gmap shadows, we have to store
the requested edat level in the gmap shadow.

The edat level used during shadow translation is a property of the gmap
shadow. Depending on that level, the gmap shadow will look differently for
the same guest tables. We have to store it internally in order to support
it later.

Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-20 09:54:47 +02:00
David Hildenbrand
00fc062d53 s390/mm: push ste protection down to shadow pte
If a guest ste is read-only, it doesn't make sense to force the ptes in as
writable in the host. If the source page is read-only in the host, it won't
have to be made writable. Please note that if the source page is not
available, it will still be faulted in writable. This can be changed
internally later on.

If ste protection is removed, underlying shadow tables are also removed,
therefore this change does not affect the guest.

Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-20 09:54:45 +02:00
David Hildenbrand
f4debb4090 s390/mm: take ipte_lock during shadow faults
Let's take the ipte_lock while working on guest 2 provided page table, just
like the other gaccess functions.

Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-20 09:54:40 +02:00
David Hildenbrand
7a6741576b s390/mm: protection exceptions are corrrectly shadowed
As gmap shadows contains correct protection permissions, protection
exceptons can directly be forwarded to guest 3. If we would encounter
a protection exception while faulting, the next guest 3 run will
automatically handle that for us.

Keep the dat_protection logic in place, as it will be helpful later.

Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-20 09:54:34 +02:00
David Hildenbrand
e52f8b6112 s390/mm: take the mmap_sem in kvm_s390_shadow_fault()
Instead of doing it in the caller, let's just take the mmap_sem
in kvm_s390_shadow_fault(). By taking it as read, we allow parallel
faulting on shadow page tables, gmap shadow code is prepared for that.

Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-20 09:54:33 +02:00
David Hildenbrand
0f7f848915 s390/mm: fix races on gmap_shadow creation
Before any thread is allowed to use a gmap_shadow, it has to be fully
initialized. However, for invalidation to work properly, we have to
register the new gmap_shadow before we protect the parent gmap table.

Because locking is tricky, and we have to avoid duplicate gmaps, let's
introduce an initialized field, that signalizes other threads if that
gmap_shadow can already be used or if they have to retry.

Let's properly return errors using ERR_PTR() instead of simply returning
NULL, so a caller can properly react on the error.

Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-20 09:54:28 +02:00
David Hildenbrand
998f637cc4 s390/mm: avoid races on region/segment/page table shadowing
We have to unlock sg->guest_table_lock in order to call
gmap_protect_rmap(). If we sleep just before that call, another VCPU
might pick up that shadowed page table (while it is not protected yet)
and use it.

In order to avoid these races, we have to introduce a third state -
"origin set but still invalid" for an entry. This way, we can avoid
another thread already using the entry before the table is fully protected.
As soon as everything is set up, we can clear the invalid bit - if we
had no race with the unshadowing code.

Suggested-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-20 09:54:27 +02:00
David Hildenbrand
a9d23e71d7 s390/mm: shadow pages with real guest requested protection
We really want to avoid manually handling protection for nested
virtualization. By shadowing pages with the protection the guest asked us
for, the SIE can handle most protection-related actions for us (e.g.
special handling for MVPG) and we can directly forward protection
exceptions to the guest.

PTEs will now always be shadowed with the correct _PAGE_PROTECT flag.
Unshadowing will take care of any guest changes to the parent PTE and
any host changes to the host PTE. If the host PTE doesn't have the
fitting access rights or is not available, we have to fix it up.

Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-20 09:54:19 +02:00
David Hildenbrand
eea3678d43 s390/mm: flush tlb of shadows in all situations
For now, the tlb of shadow gmap is only flushed when the parent is removed,
not when it is removed upfront. Therefore other shadow gmaps can reuse the
tables without the tlb getting flushed.

Fix this by simply flushing the tlb
1. Before the shadow tables are removed (analogouos to other unshadow functions)
2. When the gmap is freed and therefore the top level pages are freed.

Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-06-20 09:54:18 +02:00
Martin Schwidefsky
aa17aa57cf s390/mm: add kvm shadow fault function
This patch introduces function kvm_s390_shadow_fault() used to resolve a
fault on a shadow gmap. This function will do validity checking and
build up the shadow page table hierarchy in order to fault in the
requested page into the shadow page table structure.

If an exception occurs while shadowing, guest 2 has to be notified about
it using either an exception or a program interrupt intercept. If
concurrent unshadowing occurres, this function will simply return with
-EAGAIN and the caller has to retry.

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 09:54:12 +02:00
Martin Schwidefsky
4be130a084 s390/mm: add shadow gmap support
For a nested KVM guest the outer KVM host needs to create shadow
page tables for the nested guest. This patch adds the basic support
to the guest address space (gmap) code.

For each guest address space the inner KVM host creates, the first
outer KVM host needs to create shadow page tables. The address space
is identified by the ASCE loaded into the control register 1 at the
time the inner SIE instruction for the second nested KVM guest is
executed. The outer KVM host creates the shadow tables starting with
the table identified by the ASCE on a on-demand basis. The outer KVM
host will get repeated faults for all the shadow tables needed to
run the second KVM guest.

While a shadow page table for the second KVM guest is active the access
to the origin region, segment and page tables needs to be restricted
for the first KVM guest. For region and segment and page tables the first
KVM guest may read the memory, but write attempt has to lead to an
unshadow.  This is done using the page invalid and read-only bits in the
page table of the first KVM guest. If the first guest re-accesses one of
the origin pages of a shadow, it gets a fault and the affected parts of
the shadow page table hierarchy needs to be removed again.

PGSTE tables don't have to be shadowed, as all interpretation assist can't
deal with the invalid bits in the shadow pte being set differently than
the original ones provided by the first KVM guest.

Many bug fixes and improvements by David Hildenbrand.

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 09:54:04 +02:00
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
8ecb1a59d6 s390/mm: use RCU for gmap notifier list and the per-mm gmap list
The gmap notifier list and the gmap list in the mm_struct change rarely.
Use RCU to optimize the reader of these lists.

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
2386145152 s390/sclp: detect storage-key facility
Let's correctly detect that facility.

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
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
David Hildenbrand
8d6037a7b4 s390/mm: simplify get_guest_storage_key
We can safe a few LOC and make that function easier to understand
by rewriting existing code.

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 12:07:27 +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
David Hildenbrand
c427c42cd6 s390/mm: don't drop errors in get_guest_storage_key
Commit 1e133ab296 ("s390/mm: split arch/s390/mm/pgtable.c") changed
the return value of get_guest_storage_key to an unsigned char, resulting
in -EFAULT getting interpreted as a valid storage key.

Cc: stable@vger.kernel.org # 4.6+
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 12:07:26 +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
9c375490fc s390/sclp: detect interlock-and-broadcast-suppression facility
Let's detect that facility.

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