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Introduced with ESOP, therefore available for the guest if it
is allowed to use ESOP.
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>
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If guest 2 is allowed to use edat 1 / edat 2, it can also set it up for
guest 3, so let's properly check and forward the edat cpuflags.
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>
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As soon as we forward an ibc to guest 2 (indicated via
kvm->arch.model.ibc), he can also use it for guest 3. Let's properly round
the ibc up/down, so we avoid any potential validity icpts from the
underlying SIE, if it doesn't simply round the values.
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>
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In order to not always map the prefix, we have to take care of certain
aspects that implicitly unmap the prefix:
- Changes to the prefix address
- Changes to MSO, because the HVA of the prefix is changed
- Changes of the gmap shadow (e.g. unshadowed, asce or edat changes)
By properly handling these cases, we can stop remapping the prefix when
there is no reason to do so.
This also allows us now to not acquire any gmap shadow locks when
rerunning the vsie and still having a valid gmap shadow.
Please note, to detect changing gmap shadows, we have to keep the reference
of the gmap shadow. The address of a gmap shadow does otherwise not
reliably indicate if the gmap shadow has changed (the memory chunk
could get reused).
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>
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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>
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Pull s390 fixes from Martin Schwidefsky:
"Two more bugs fixes for 4.7:
- a KVM regression introduced with the pgtable.c code split
- a perf issue with two hardware PMUs using a shared event context"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
s390/cpum_cf: use perf software context for hardware counters
KVM: s390/mm: Fix CMMA reset during reboot
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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>
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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>
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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>
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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>
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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>
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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>
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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>
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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>
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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>
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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>
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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>
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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>
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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>
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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>
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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>
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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>
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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>
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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>
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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>
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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>
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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>
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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>
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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>
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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>
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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>
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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>
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On s390, there are two different hardware PMUs for counting and
sampling. Previously, both PMUs have shared the perf_hw_context
which is not correct and, recently, results in this warning:
------------[ cut here ]------------
WARNING: CPU: 5 PID: 1 at kernel/events/core.c:8485 perf_pmu_register+0x420/0x428
Modules linked in:
CPU: 5 PID: 1 Comm: swapper/0 Not tainted 4.7.0-rc1+ #2
task: 00000009c5240000 ti: 00000009c5234000 task.ti: 00000009c5234000
Krnl PSW : 0704c00180000000 0000000000220c50 (perf_pmu_register+0x420/0x428)
R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:3 CC:0 PM:0 RI:0 EA:3
Krnl GPRS: ffffffffffffffff 0000000000b15ac6 0000000000000000 00000009cb440000
000000000022087a 0000000000000000 0000000000b78fa0 0000000000000000
0000000000a9aa90 0000000000000084 0000000000000005 000000000088a97a
0000000000000004 0000000000749dd0 000000000022087a 00000009c5237cc0
Krnl Code: 0000000000220c44: a7f4ff54 brc 15,220aec
0000000000220c48: 92011000 mvi 0(%r1),1
#0000000000220c4c: a7f40001 brc 15,220c4e
>0000000000220c50: a7f4ff12 brc 15,220a74
0000000000220c54: 0707 bcr 0,%r7
0000000000220c56: 0707 bcr 0,%r7
0000000000220c58: ebdff0800024 stmg %r13,%r15,128(%r15)
0000000000220c5e: a7f13fe0 tmll %r15,16352
Call Trace:
([<000000000022087a>] perf_pmu_register+0x4a/0x428)
([<0000000000b2c25c>] init_cpum_sampling_pmu+0x14c/0x1f8)
([<0000000000100248>] do_one_initcall+0x48/0x140)
([<0000000000b25d26>] kernel_init_freeable+0x1e6/0x2a0)
([<000000000072bda4>] kernel_init+0x24/0x138)
([<000000000073495e>] kernel_thread_starter+0x6/0xc)
([<0000000000734958>] kernel_thread_starter+0x0/0xc)
Last Breaking-Event-Address:
[<0000000000220c4c>] perf_pmu_register+0x41c/0x428
---[ end trace 0c6ef9f5b771ad97 ]---
Using the perf_sw_context is an option because the cpum_cf PMU does
not use interrupts. To make this more clear, initialize the
capabilities in the PMU structure.
Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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Since all architectures have this implemented now natively, remove this
dead code.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-arch@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Implement FETCH-OP atomic primitives, these are very similar to the
existing OP-RETURN primitives we already have, except they return the
value of the atomic variable _before_ modification.
This is especially useful for irreversible operations -- such as
bitops (because it becomes impossible to reconstruct the state prior
to modification).
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-arch@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-s390@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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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>
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The last in-kernel user is gone so we can finally remove this code.
Reviewed-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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Implement calculation of loops_per_jiffies with fp instructions which
are available on all 64 bit machines.
To save and restore floating point register context use the new vx support
functions.
Reviewed-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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Add a crypto API module to access the vector extension based CRC-32
implementations. Users can request the optimized implementation through
the shash crypto API interface.
Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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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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Close the hole where ptrace can change a syscall out from under seccomp.
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: linux-s390@vger.kernel.org
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Currently, if arch code wants to supply seccomp_data directly to
seccomp (which is generally much faster than having seccomp do it
using the syscall_get_xyz() API), it has to use the two-phase
seccomp hooks. Add it to the easy hooks, too.
Cc: linux-arch@vger.kernel.org
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
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Use vector instructions to optimize the computation of CRC-32 checksums.
An optimized version is provided for CRC-32 (IEEE 802.3 Ethernet) in
normal and bitreflected domain, as well as, for bitreflected CRC-32C
(Castagnoli).
Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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Introduce the kernel_fpu_begin() and kernel_fpu_end() function
to enclose any in-kernel use of FPU instructions and registers.
In enclosed sections, you can perform floating-point or vector
(SIMD) computations. The functions take care of saving and
restoring FPU register contents and controls.
For usage details, see the guidelines in arch/s390/include/asm/fpu/api.h
Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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The usual problem for code that is ifdef'ed out is that it doesn't
compile after a while. That's also the case for the storage key
initialisation code, if it would be used (set PAGE_DEFAULT_KEY to
something not zero):
./arch/s390/include/asm/page.h: In function 'storage_key_init_range':
./arch/s390/include/asm/page.h:36:2: error: implicit declaration of function '__storage_key_init_range'
Since the code itself has been useful for debugging purposes several
times, remove the ifdefs and make sure the code gets compiler
coverage. The cost for this is eight bytes.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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This patch updates/fixes all spin_unlock_wait() implementations.
The update is in semantics; where it previously was only a control
dependency, we now upgrade to a full load-acquire to match the
store-release from the spin_unlock() we waited on. This ensures that
when spin_unlock_wait() returns, we're guaranteed to observe the full
critical section we waited on.
This fixes a number of spin_unlock_wait() users that (not
unreasonably) rely on this.
I also fixed a number of ticket lock versions to only wait on the
current lock holder, instead of for a full unlock, as this is
sufficient.
Furthermore; again for ticket locks; I added an smp_rmb() in between
the initial ticket load and the spin loop testing the current value
because I could not convince myself the address dependency is
sufficient, esp. if the loads are of different sizes.
I'm more than happy to remove this smp_rmb() again if people are
certain the address dependency does indeed work as expected.
Note: PPC32 will be fixed independently
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: chris@zankel.net
Cc: cmetcalf@mellanox.com
Cc: davem@davemloft.net
Cc: dhowells@redhat.com
Cc: james.hogan@imgtec.com
Cc: jejb@parisc-linux.org
Cc: linux@armlinux.org.uk
Cc: mpe@ellerman.id.au
Cc: ralf@linux-mips.org
Cc: realmz6@gmail.com
Cc: rkuo@codeaurora.org
Cc: rth@twiddle.net
Cc: schwidefsky@de.ibm.com
Cc: tony.luck@intel.com
Cc: vgupta@synopsys.com
Cc: ysato@users.sourceforge.jp
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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I don't have a z10 to test this anymore, so I have no idea if the code
works at all or even crashes. I can try to emulate, but it is just
guess work.
Nor do we know if the z10 special handling is performance wise still
better than the generic handling. There have been a lot of changes to
the scheduler.
Therefore let's play safe and remove the special handling.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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The z13 machine added a fourth level to the cpu topology
information. The new top level is called drawer.
A drawer contains two books, which used to be the top level.
Adding this additional scheduling domain did show performance
improvements for some workloads of up to 8%, while there don't
seem to be any workloads impacted in a negative way.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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David Hildenbrand
Linus Torvalds
Martin Schwidefsky
Hendrik Brueckner
Peter Zijlstra
Paolo Bonzini
Heiko Carstens
Kees Cook
Andy Lutomirski
Andrea Gelmini