Commit Graph

172 Commits

Author SHA1 Message Date
Thomas Huth 81a8f2beb3 s390/mm: silence compiler warning when compiling without CONFIG_PGSTE
If CONFIG_PGSTE is not set (e.g. when compiling without KVM), GCC complains:

  CC      arch/s390/mm/pgtable.o
arch/s390/mm/pgtable.c:413:15: warning: ‘pmd_alloc_map’ defined but not
 used [-Wunused-function]
 static pmd_t *pmd_alloc_map(struct mm_struct *mm, unsigned long addr)
               ^~~~~~~~~~~~~

Wrap the function with "#ifdef CONFIG_PGSTE" to silence the warning.

Signed-off-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-10 17:48:28 +02:00
Aneesh Kumar K.V 04a8645304 mm: update ptep_modify_prot_commit to take old pte value as arg
Architectures like ppc64 require to do a conditional tlb flush based on
the old and new value of pte.  Enable that by passing old pte value as
the arg.

Link: http://lkml.kernel.org/r/20190116085035.29729-3-aneesh.kumar@linux.ibm.com
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-03-05 21:07:18 -08:00
Aneesh Kumar K.V 0cbe3e26ab mm: update ptep_modify_prot_start/commit to take vm_area_struct as arg
Patch series "NestMMU pte upgrade workaround for mprotect", v5.

We can upgrade pte access (R -> RW transition) via mprotect.  We need to
make sure we follow the recommended pte update sequence as outlined in
commit bd5050e38a ("powerpc/mm/radix: Change pte relax sequence to
handle nest MMU hang") for such updates.  This patch series does that.

This patch (of 5):

Some architectures may want to call flush_tlb_range from these helpers.

Link: http://lkml.kernel.org/r/20190116085035.29729-2-aneesh.kumar@linux.ibm.com
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-03-05 21:07:18 -08:00
Christoph Hellwig 32b77252f4 s390: remove the ptep_modify_prot_{start,commit} exports
These two functions are only used by core MM code, so no need to export
them.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-01-18 09:34:17 +01:00
Janosch Frank a9e00d8349 s390/mm: Add huge page gmap linking support
Let's allow huge pmd linking when enabled through the
KVM_CAP_S390_HPAGE_1M capability. Also we can now restrict gmap
invalidation and notification to the cases where the capability has
been activated and save some cycles when that's not the case.

Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
2018-07-30 23:13:38 +02:00
Janosch Frank 637ff9efe5 s390/mm: Add huge pmd storage key handling
Storage keys for guests with huge page mappings have to be managed in
hardware. There are no PGSTEs for PMDs that we could use to retain the
guests's logical view of the key.

Signed-off-by: Janosch Frank <frankja@linux.vnet.ibm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
2018-07-30 11:20:18 +01:00
Janosch Frank 0959e16867 s390/mm: Add huge page dirty sync support
To do dirty loging with huge pages, we protect huge pmds in the
gmap. When they are written to, we unprotect them and mark them dirty.

We introduce the function gmap_test_and_clear_dirty_pmd which handles
dirty sync for huge pages.

Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
Acked-by: David Hildenbrand <david@redhat.com>
2018-07-30 11:20:18 +01:00
Janosch Frank 6a3762778d s390/mm: Add gmap pmd invalidation and clearing
If the host invalidates a pmd, we also have to invalidate the
corresponding gmap pmds, as well as flush them from the TLB. This is
necessary, as we don't share the pmd tables between host and guest as
we do with ptes.

The clearing part of these three new functions sets a guest pmd entry
to _SEGMENT_ENTRY_EMPTY, so the guest will fault on it and we will
re-link it.

Flushing the gmap is not necessary in the host's lazy local and csp
cases. Both purge the TLB completely.

Signed-off-by: Janosch Frank <frankja@linux.vnet.ibm.com>
Reviewed-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Acked-by: David Hildenbrand <david@redhat.com>
2018-07-30 11:20:17 +01:00
Janosch Frank 55531b7431 KVM: s390: Add storage key facility interpretation control
Up to now we always expected to have the storage key facility
available for our (non-VSIE) KVM guests. For huge page support, we
need to be able to disable it, so let's introduce that now.

We add the use_skf variable to manage KVM storage key facility
usage. Also we rename use_skey in the mm context struct to uses_skeys
to make it more clear that it is an indication that the vm actively
uses storage keys.

Signed-off-by: Janosch Frank <frankja@linux.vnet.ibm.com>
Reviewed-by: Farhan Ali <alifm@linux.vnet.ibm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2018-05-17 09:00:41 +02:00
Greg Kroah-Hartman ac41aaeedc s390: mm: add SPDX identifiers to the remaining files
It's good to have SPDX identifiers in all files to make it easier to
audit the kernel tree for correct licenses.

Update the arch/s390/mm/ files with the correct SPDX license
identifier based on the license text in the file itself.  The SPDX
identifier is a legally binding shorthand, which can be used instead of
the full boiler plate text.

This work is based on a script and data from Thomas Gleixner, Philippe
Ombredanne, and Kate Stewart.

Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Cornelia Huck <cohuck@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Kate Stewart <kstewart@linuxfoundation.org>
Cc: Philippe Ombredanne <pombredanne@nexb.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-11-24 15:37:15 +01:00
Radim Krčmář 6e0ff1b4db KVM: s390: Fixes and features for 4.14
- merge of topic branch tlb-flushing from the s390 tree to get the
   no-dat base features
 - merge of kvm/master to avoid conflicts with additional sthyi fixes
 - wire up the no-dat enhancements in KVM
 - multiple epoch facility (z14 feature)
 - Configuration z/Architecture Mode
 - more sthyi fixes
 - gdb server range checking fix
 - small code cleanups
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Merge tag 'kvm-s390-next-4.14-2' of git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux

KVM: s390: Fixes and features for 4.14

- merge of topic branch tlb-flushing from the s390 tree to get the
  no-dat base features
- merge of kvm/master to avoid conflicts with additional sthyi fixes
- wire up the no-dat enhancements in KVM
- multiple epoch facility (z14 feature)
- Configuration z/Architecture Mode
- more sthyi fixes
- gdb server range checking fix
- small code cleanups
2017-09-07 16:46:46 +02:00
Claudio Imbrenda 1bab1c02af KVM: s390: expose no-DAT to guest and migration support
The STFLE bit 147 indicates whether the ESSA no-DAT operation code is
valid, the bit is not normally provided to the host; the host is
instead provided with an SCLP bit that indicates whether guests can
support the feature.

This patch:
* enables the STFLE bit in the guest if the corresponding SCLP bit is
  present in the host.
* adds support for migrating the no-DAT bit in the PGSTEs
* fixes the software interpretation of the ESSA instruction that is
  used when migrating, both for the new operation code and for the old
  "set stable", as per specifications.

Signed-off-by: Claudio Imbrenda <imbrenda@linux.vnet.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2017-08-29 15:15:56 +02:00
Martin Schwidefsky cd774b9076 s390/mm,kvm: use nodat PGSTE tag to optimize TLB flushing
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-07-25 06:55:35 +02:00
Martin Schwidefsky 28c807e513 s390/mm: add guest ASCE TLB flush optimization
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-07-25 06:55:33 +02:00
Martin Schwidefsky 118bd31bea s390/mm: add no-dat TLB flush optimization
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-07-25 06:55:30 +02:00
Christian Borntraeger 97ca7bfc19 s390/mm: set change and reference bit on lazy key enablement
When we enable storage keys for a guest lazily, we reset the ACC and F
values. That is correct assuming that these are 0 on a clear reset and
the guest obviously has not used any key setting instruction.

We also zero out the change and reference bit. This is not correct as
the architecture prefers over-indication instead of under-indication
for the keyless->keyed transition.

This patch fixes the behaviour and always sets guest change and guest
reference for all guest storage keys on the keyless -> keyed switch.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-07-13 11:28:29 +02:00
Martin Schwidefsky 1aea9b3f92 s390/mm: implement 5 level pages tables
Add the logic to upgrade the page table for a 64-bit process to
five levels. This increases the TASK_SIZE from 8PB to 16EB-4K.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-06-12 16:25:54 +02:00
Claudio Imbrenda 2d42f94773 s390/kvm: Add PGSTE manipulation functions
Add PGSTE manipulation functions:
* set_pgste_bits sets specific bits in a PGSTE
* get_pgste returns the whole PGSTE
* pgste_perform_essa manipulates a PGSTE to set specific storage states
* ESSA_[SG]ET_* macros used to indicate the action for manipulate_pgste

Signed-off-by: Claudio Imbrenda <imbrenda@linux.vnet.ibm.com>
Reviewed-by: Janosch Frank <frankja@de.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-04-20 13:33:08 +02:00
Janosch Frank 2e4d88009f KVM: s390: Fix guest migration for huge guests resulting in panic
While we can technically not run huge page guests right now, we can
setup a guest with huge pages. Trying to migrate it will trigger a
VM_BUG_ON and, if the kernel is not configured to panic on a BUG, it
will happily try to work on non-existing page table entries.

With this patch, we always return "dirty" if we encounter a large page
when migrating. This at least fixes the immediate problem until we
have proper handling for both kind of pages.

Fixes: 15f36eb ("KVM: s390: Add proper dirty bitmap support to S390 kvm.")
Cc: <stable@vger.kernel.org> # 3.16+

Signed-off-by: Janosch Frank <frankja@linux.vnet.ibm.com>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-03-02 17:17:16 +01:00
Linus Torvalds fd7e9a8834 4.11 is going to be a relatively large release for KVM, with a little over
200 commits and noteworthy changes for most architectures.
 
 * ARM:
 - GICv3 save/restore
 - cache flushing fixes
 - working MSI injection for GICv3 ITS
 - physical timer emulation
 
 * MIPS:
 - various improvements under the hood
 - support for SMP guests
 - a large rewrite of MMU emulation.  KVM MIPS can now use MMU notifiers
 to support copy-on-write, KSM, idle page tracking, swapping, ballooning
 and everything else.  KVM_CAP_READONLY_MEM is also supported, so that
 writes to some memory regions can be treated as MMIO.  The new MMU also
 paves the way for hardware virtualization support.
 
 * PPC:
 - support for POWER9 using the radix-tree MMU for host and guest
 - resizable hashed page table
 - bugfixes.
 
 * s390: expose more features to the guest
 - more SIMD extensions
 - instruction execution protection
 - ESOP2
 
 * x86:
 - improved hashing in the MMU
 - faster PageLRU tracking for Intel CPUs without EPT A/D bits
 - some refactoring of nested VMX entry/exit code, preparing for live
 migration support of nested hypervisors
 - expose yet another AVX512 CPUID bit
 - host-to-guest PTP support
 - refactoring of interrupt injection, with some optimizations thrown in
 and some duct tape removed.
 - remove lazy FPU handling
 - optimizations of user-mode exits
 - optimizations of vcpu_is_preempted() for KVM guests
 
 * generic:
 - alternative signaling mechanism that doesn't pound on tsk->sighand->siglock
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull KVM updates from Paolo Bonzini:
 "4.11 is going to be a relatively large release for KVM, with a little
  over 200 commits and noteworthy changes for most architectures.

  ARM:
   - GICv3 save/restore
   - cache flushing fixes
   - working MSI injection for GICv3 ITS
   - physical timer emulation

  MIPS:
   - various improvements under the hood
   - support for SMP guests
   - a large rewrite of MMU emulation. KVM MIPS can now use MMU
     notifiers to support copy-on-write, KSM, idle page tracking,
     swapping, ballooning and everything else. KVM_CAP_READONLY_MEM is
     also supported, so that writes to some memory regions can be
     treated as MMIO. The new MMU also paves the way for hardware
     virtualization support.

  PPC:
   - support for POWER9 using the radix-tree MMU for host and guest
   - resizable hashed page table
   - bugfixes.

  s390:
   - expose more features to the guest
   - more SIMD extensions
   - instruction execution protection
   - ESOP2

  x86:
   - improved hashing in the MMU
   - faster PageLRU tracking for Intel CPUs without EPT A/D bits
   - some refactoring of nested VMX entry/exit code, preparing for live
     migration support of nested hypervisors
   - expose yet another AVX512 CPUID bit
   - host-to-guest PTP support
   - refactoring of interrupt injection, with some optimizations thrown
     in and some duct tape removed.
   - remove lazy FPU handling
   - optimizations of user-mode exits
   - optimizations of vcpu_is_preempted() for KVM guests

  generic:
   - alternative signaling mechanism that doesn't pound on
     tsk->sighand->siglock"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (195 commits)
  x86/kvm: Provide optimized version of vcpu_is_preempted() for x86-64
  x86/paravirt: Change vcp_is_preempted() arg type to long
  KVM: VMX: use correct vmcs_read/write for guest segment selector/base
  x86/kvm/vmx: Defer TR reload after VM exit
  x86/asm/64: Drop __cacheline_aligned from struct x86_hw_tss
  x86/kvm/vmx: Simplify segment_base()
  x86/kvm/vmx: Get rid of segment_base() on 64-bit kernels
  x86/kvm/vmx: Don't fetch the TSS base from the GDT
  x86/asm: Define the kernel TSS limit in a macro
  kvm: fix page struct leak in handle_vmon
  KVM: PPC: Book3S HV: Disable HPT resizing on POWER9 for now
  KVM: Return an error code only as a constant in kvm_get_dirty_log()
  KVM: Return an error code only as a constant in kvm_get_dirty_log_protect()
  KVM: Return directly after a failed copy_from_user() in kvm_vm_compat_ioctl()
  KVM: x86: remove code for lazy FPU handling
  KVM: race-free exit from KVM_RUN without POSIX signals
  KVM: PPC: Book3S HV: Turn "KVM guest htab" message into a debug message
  KVM: PPC: Book3S PR: Ratelimit copy data failure error messages
  KVM: Support vCPU-based gfn->hva cache
  KVM: use separate generations for each address space
  ...
2017-02-22 18:22:53 -08:00
Linus Torvalds ff47d8c050 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux
Pull s390 updates from Martin Schwidefsky:

 - New entropy generation for the pseudo random number generator.

 - Early boot printk output via sclp to help debug crashes on boot. This
   needs to be enabled with a kernel parameter.

 - Add proper no-execute support with a bit in the page table entry.

 - Bug fixes and cleanups.

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (65 commits)
  s390/syscall: fix single stepped system calls
  s390/zcrypt: make ap_bus explicitly non-modular
  s390/zcrypt: Removed unneeded debug feature directory creation.
  s390: add missing "do {} while (0)" loop constructs to multiline macros
  s390/mm: add cond_resched call to kernel page table dumper
  s390: get rid of MACHINE_HAS_PFMF and MACHINE_HAS_HPAGE
  s390/mm: make memory_block_size_bytes available for !MEMORY_HOTPLUG
  s390: replace ACCESS_ONCE with READ_ONCE
  s390: Audit and remove any remaining unnecessary uses of module.h
  s390: mm: Audit and remove any unnecessary uses of module.h
  s390: kernel: Audit and remove any unnecessary uses of module.h
  s390/kdump: Use "LINUX" ELF note name instead of "CORE"
  s390: add no-execute support
  s390: report new vector facilities
  s390: use correct input data address for setup_randomness
  s390/sclp: get rid of common response code handling
  s390/sclp: don't add new lines to each printed string
  s390/sclp: make early sclp code readable
  s390/sclp: disable early sclp code as soon as the base sclp driver is active
  s390/sclp: move early printk code to drivers
  ...
2017-02-22 10:20:04 -08:00
Martin Schwidefsky 57d7f939e7 s390: add no-execute support
Bit 0x100 of a page table, segment table of region table entry
can be used to disallow code execution for the virtual addresses
associated with the entry.

There is one tricky bit, the system call to return from a signal
is part of the signal frame written to the user stack. With a
non-executable stack this would stop working. To avoid breaking
things the protection fault handler checks the opcode that caused
the fault for 0x0a77 (sys_sigreturn) and 0x0aad (sys_rt_sigreturn)
and injects a system call. This is preferable to the alternative
solution with a stub function in the vdso because it works for
vdso=off and statically linked binaries as well.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-02-08 14:13:25 +01:00
Janosch Frank 4bead2a423 KVM: s390: Fix RRBE return code not being CC
reset_guest_reference_bit needs to return the CC, so we can set it in
the guest PSW when emulating RRBE. Right now it only returns 0.

Let's fix that.

Signed-off-by: Janosch Frank <frankja@linux.vnet.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2017-01-30 11:19:17 +01:00
Christian Borntraeger 0d6da872d3 s390/mm: Fix cmma unused transfer from pgste into pte
The last pgtable rework silently disabled the CMMA unused state by
setting a local pte variable (a parameter) instead of propagating it
back into the caller. Fix it.

Fixes: ebde765c0e ("s390/mm: uninline ptep_xxx functions from pgtable.h")
Cc: stable@vger.kernel.org # v4.6+
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Claudio Imbrenda <imbrenda@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-01-24 16:03:42 +01:00
Martin Schwidefsky 47e4d851c5 s390/mm: merge local / non-local IDTE helper
Merge the __p[m|u]xdp_idte and __p[m|u]dp_idte_local functions into a
single __p[m|u]dp_idte function with an additional parameter.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-08-24 09:23:56 +02:00
Martin Schwidefsky 34eeaf376d s390/mm: merge local / non-local IPTE helper
Merge the __ptep_ipte and __ptep_ipte_local functions into a single
__ptep_ipte function with an additional parameter. The __pte_ipte_range
function is still extra as the while loops makes it hard to merge.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-08-24 09:23:55 +02:00
Linus Torvalds 221bb8a46e - ARM: GICv3 ITS emulation and various fixes. Removal of the old
VGIC implementation.
 
 - s390: support for trapping software breakpoints, nested virtualization
 (vSIE), the STHYI opcode, initial extensions for CPU model support.
 
 - MIPS: support for MIPS64 hosts (32-bit guests only) and lots of cleanups,
 preliminary to this and the upcoming support for hardware virtualization
 extensions.
 
 - x86: support for execute-only mappings in nested EPT; reduced vmexit
 latency for TSC deadline timer (by about 30%) on Intel hosts; support for
 more than 255 vCPUs.
 
 - PPC: bugfixes.
 
 The ugly bit is the conflicts.  A couple of them are simple conflicts due
 to 4.7 fixes, but most of them are with other trees. There was definitely
 too much reliance on Acked-by here.  Some conflicts are for KVM patches
 where _I_ gave my Acked-by, but the worst are for this pull request's
 patches that touch files outside arch/*/kvm.  KVM submaintainers should
 probably learn to synchronize better with arch maintainers, with the
 latter providing topic branches whenever possible instead of Acked-by.
 This is what we do with arch/x86.  And I should learn to refuse pull
 requests when linux-next sends scary signals, even if that means that
 submaintainers have to rebase their branches.
 
 Anyhow, here's the list:
 
 - arch/x86/kvm/vmx.c: handle_pcommit and EXIT_REASON_PCOMMIT was removed
 by the nvdimm tree.  This tree adds handle_preemption_timer and
 EXIT_REASON_PREEMPTION_TIMER at the same place.  In general all mentions
 of pcommit have to go.
 
 There is also a conflict between a stable fix and this patch, where the
 stable fix removed the vmx_create_pml_buffer function and its call.
 
 - virt/kvm/kvm_main.c: kvm_cpu_notifier was removed by the hotplug tree.
 This tree adds kvm_io_bus_get_dev at the same place.
 
 - virt/kvm/arm/vgic.c: a few final bugfixes went into 4.7 before the
 file was completely removed for 4.8.
 
 - include/linux/irqchip/arm-gic-v3.h: this one is entirely our fault;
 this is a change that should have gone in through the irqchip tree and
 pulled by kvm-arm.  I think I would have rejected this kvm-arm pull
 request.  The KVM version is the right one, except that it lacks
 GITS_BASER_PAGES_SHIFT.
 
 - arch/powerpc: what a mess.  For the idle_book3s.S conflict, the KVM
 tree is the right one; everything else is trivial.  In this case I am
 not quite sure what went wrong.  The commit that is causing the mess
 (fd7bacbca4, "KVM: PPC: Book3S HV: Fix TB corruption in guest exit
 path on HMI interrupt", 2016-05-15) touches both arch/powerpc/kernel/
 and arch/powerpc/kvm/.  It's large, but at 396 insertions/5 deletions
 I guessed that it wasn't really possible to split it and that the 5
 deletions wouldn't conflict.  That wasn't the case.
 
 - arch/s390: also messy.  First is hypfs_diag.c where the KVM tree
 moved some code and the s390 tree patched it.  You have to reapply the
 relevant part of commits 6c22c98637, plus all of e030c1125e, to
 arch/s390/kernel/diag.c.  Or pick the linux-next conflict
 resolution from http://marc.info/?l=kvm&m=146717549531603&w=2.
 Second, there is a conflict in gmap.c between a stable fix and 4.8.
 The KVM version here is the correct one.
 
 I have pushed my resolution at refs/heads/merge-20160802 (commit
 3d1f53419842) at git://git.kernel.org/pub/scm/virt/kvm/kvm.git.
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull KVM updates from Paolo Bonzini:

 - ARM: GICv3 ITS emulation and various fixes.  Removal of the
   old VGIC implementation.

 - s390: support for trapping software breakpoints, nested
   virtualization (vSIE), the STHYI opcode, initial extensions
   for CPU model support.

 - MIPS: support for MIPS64 hosts (32-bit guests only) and lots
   of cleanups, preliminary to this and the upcoming support for
   hardware virtualization extensions.

 - x86: support for execute-only mappings in nested EPT; reduced
   vmexit latency for TSC deadline timer (by about 30%) on Intel
   hosts; support for more than 255 vCPUs.

 - PPC: bugfixes.

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (302 commits)
  KVM: PPC: Introduce KVM_CAP_PPC_HTM
  MIPS: Select HAVE_KVM for MIPS64_R{2,6}
  MIPS: KVM: Reset CP0_PageMask during host TLB flush
  MIPS: KVM: Fix ptr->int cast via KVM_GUEST_KSEGX()
  MIPS: KVM: Sign extend MFC0/RDHWR results
  MIPS: KVM: Fix 64-bit big endian dynamic translation
  MIPS: KVM: Fail if ebase doesn't fit in CP0_EBase
  MIPS: KVM: Use 64-bit CP0_EBase when appropriate
  MIPS: KVM: Set CP0_Status.KX on MIPS64
  MIPS: KVM: Make entry code MIPS64 friendly
  MIPS: KVM: Use kmap instead of CKSEG0ADDR()
  MIPS: KVM: Use virt_to_phys() to get commpage PFN
  MIPS: Fix definition of KSEGX() for 64-bit
  KVM: VMX: Add VMCS to CPU's loaded VMCSs before VMPTRLD
  kvm: x86: nVMX: maintain internal copy of current VMCS
  KVM: PPC: Book3S HV: Save/restore TM state in H_CEDE
  KVM: PPC: Book3S HV: Pull out TM state save/restore into separate procedures
  KVM: arm64: vgic-its: Simplify MAPI error handling
  KVM: arm64: vgic-its: Make vgic_its_cmd_handle_mapi similar to other handlers
  KVM: arm64: vgic-its: Turn device_id validation into generic ID validation
  ...
2016-08-02 16:11:27 -04:00
Gerald Schaefer d08de8e2d8 s390/mm: add support for 2GB hugepages
This adds support for 2GB hugetlbfs pages on s390.

Reviewed-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-07-06 08:46:43 +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
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 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 64f31d5802 s390/mm: simplify the TLB flushing code
ptep_flush_lazy and pmdp_flush_lazy use mm->context.attach_count to
decide between a lazy TLB flush vs an immediate TLB flush. The field
contains two 16-bit counters, the number of CPUs that have the mm
attached and can create TLB entries for it and the number of CPUs in
the middle of a page table update.

The __tlb_flush_asce, ptep_flush_direct and pmdp_flush_direct functions
use the attach counter and a mask check with mm_cpumask(mm) to decide
between a local flush local of the current CPU and a global flush.

For all these functions the decision between lazy vs immediate and
local vs global TLB flush can be based on CPU masks. There are two
masks:  the mm->context.cpu_attach_mask with the CPUs that are actively
using the mm, and the mm_cpumask(mm) with the CPUs that have used the
mm since the last full flush. The decision between lazy vs immediate
flush is based on the mm->context.cpu_attach_mask, to decide between
local vs global flush the mm_cpumask(mm) is used.

With this patch all checks will use the CPU masks, the old counter
mm->context.attach_count with its two 16-bit values is turned into a
single counter mm->context.flush_count that keeps track of the number
of CPUs with incomplete page table updates. The sole user of this
counter is finish_arch_post_lock_switch() which waits for the end of
all page table updates.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-06-13 15:58:22 +02:00
Martin Schwidefsky a9809407f6 s390/mm: fix vunmap vs finish_arch_post_lock_switch
The vunmap_pte_range() function calls ptep_get_and_clear() without any
locking. ptep_get_and_clear() uses ptep_xchg_lazy()/ptep_flush_direct()
for the page table update. ptep_flush_direct requires that preemption
is disabled, but without any locking this is not the case. If the kernel
preempts the task while the attach_counter is increased an endless loop
in finish_arch_post_lock_switch() will occur the next time the task is
scheduled.

Add explicit preempt_disable()/preempt_enable() calls to the relevant
functions in arch/s390/mm/pgtable.c.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-06-13 15:58:21 +02:00
Christian Borntraeger 1c343f7b0e KVM: s390/mm: Fix CMMA reset during reboot
commit 1e133ab296 ("s390/mm: split arch/s390/mm/pgtable.c") factored
out the page table handling code from __gmap_zap and  __s390_reset_cmma
into ptep_zap_unused and added a simple flag that tells which one of the
function (reset or not) is to be made. This also changed the behaviour,
as it also zaps unused page table entries on reset.
Turns out that this is wrong as s390_reset_cmma uses the page walker,
which DOES NOT take the ptl lock.

The most simple fix is to not do the zapping part on reset (which uses
the walker)

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Fixes: 1e133ab296 ("s390/mm: split arch/s390/mm/pgtable.c")
Cc: stable@vger.kernel.org # 4.6+
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-06-13 15:58:09 +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 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 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
Martin Schwidefsky 1e133ab296 s390/mm: split arch/s390/mm/pgtable.c
The pgtable.c file is quite big, before it grows any larger split it
into pgtable.c, pgalloc.c and gmap.c. In addition move the gmap related
header definitions into the new gmap.h header and all of the pgste
helpers from pgtable.h to pgtable.c.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-03-08 15:00:15 +01:00
Martin Schwidefsky 227be799c3 s390/mm: uninline pmdp_xxx functions from pgtable.h
The pmdp_xxx function are smaller than their ptep_xxx counterparts
but to keep things symmetrical unline them as well.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-03-08 15:00:14 +01:00
Martin Schwidefsky ebde765c0e s390/mm: uninline ptep_xxx functions from pgtable.h
The code in the various ptep_xxx functions has grown quite large,
consolidate them to four out-of-line functions:
  ptep_xchg_direct to exchange a pte with another with immediate flushing
  ptep_xchg_lazy to exchange a pte with another in a batched update
  ptep_modify_prot_start to begin a protection flags update
  ptep_modify_prot_commit to commit a protection flags update

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-03-08 15:00:12 +01:00
Martin Schwidefsky 443a813304 s390/kvm: simplify set_guest_storage_key
Git commit ab3f285f22
"KVM: s390/mm: try a cow on read only pages for key ops"
added a fixup_user_fault to set_guest_storage_key force a copy on
write if the page is mapped read-only. This is supposed to fix the
problem of differing storage keys for shared mappings, e.g. the
empty_zero_page.
But if the storage key is set before the pte is mapped the storage
key update is done on the pgste. A later fault will happily map the
shared page with the key from the pgste.

Eventually git commit 2faee8ff9d
"s390/mm: prevent and break zero page mappings in case of storage keys"
fixed this problem for the empty_zero_page. The commit makes sure that
guests enabled for storage keys will not use the empty_zero_page at all.

As the call to fixup_user_fault in set_guest_storage_key depends on the
order of the storage key operation vs. the fault that maps the pte
it does not really fix anything. Just remove it.

Reviewed-by: Dominik Dingel <dingel@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-03-02 06:44:22 -06:00
Dominik Dingel a9d7ab9781 s390/mm: use TASK_MAX_SIZE where applicable
To improve readability we can use TASK_MAX_SIZE when we just check for the
upper limit.  All places explicitly dealing with 3 vs 4 level pgtables
were left unchanged.

Signed-off-by: Dominik Dingel <dingel@linux.vnet.ibm.com>
Reviewed-By: Sascha Silbe <silbe@linux.vnet.ibm.com>
2016-01-19 12:14:01 +01:00
Dominik Dingel fef8953ae4 s390/mm: enable fixup_user_fault retrying
By passing a non-null flag we allow fixup_user_fault to retry, which
enables userfaultfd.  As during these retries we might drop the mmap_sem
we need to check if that happened and redo the complete chain of
actions.

Signed-off-by: Dominik Dingel <dingel@linux.vnet.ibm.com>
Reviewed-by: Andrea Arcangeli <aarcange@redhat.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: "Jason J. Herne" <jjherne@linux.vnet.ibm.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Eric B Munson <emunson@akamai.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Dominik Dingel <dingel@linux.vnet.ibm.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-15 17:56:32 -08:00
Dominik Dingel 4a9e1cda27 mm: bring in additional flag for fixup_user_fault to signal unlock
During Jason's work with postcopy migration support for s390 a problem
regarding gmap faults was discovered.

The gmap code will call fixup_user_fault which will end up always in
handle_mm_fault.  Till now we never cared about retries, but as the
userfaultfd code kind of relies on it.  this needs some fix.

This patchset does not take care of the futex code.  I will now look
closer at this.

This patch (of 2):

With the introduction of userfaultfd, kvm on s390 needs fixup_user_fault
to pass in FAULT_FLAG_ALLOW_RETRY and give feedback if during the
faulting we ever unlocked mmap_sem.

This patch brings in the logic to handle retries as well as it cleans up
the current documentation.  fixup_user_fault was not having the same
semantics as filemap_fault.  It never indicated if a retry happened and
so a caller wasn't able to handle that case.  So we now changed the
behaviour to always retry a locked mmap_sem.

Signed-off-by: Dominik Dingel <dingel@linux.vnet.ibm.com>
Reviewed-by: Andrea Arcangeli <aarcange@redhat.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: "Jason J. Herne" <jjherne@linux.vnet.ibm.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Eric B Munson <emunson@akamai.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Dominik Dingel <dingel@linux.vnet.ibm.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-15 17:56:32 -08:00
Kirill A. Shutemov fecffad254 s390, thp: remove infrastructure for handling splitting PMDs
With new refcounting we don't need to mark PMDs splitting.  Let's drop
code to handle this.

pmdp_splitting_flush() is not needed too: on splitting PMD we will do
pmdp_clear_flush() + set_pte_at().  pmdp_clear_flush() will do IPI as
needed for fast_gup.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Jerome Marchand <jmarchan@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Steve Capper <steve.capper@linaro.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-15 17:56:32 -08:00
Jerome Marchand eca56ff906 mm, shmem: add internal shmem resident memory accounting
Currently looking at /proc/<pid>/status or statm, there is no way to
distinguish shmem pages from pages mapped to a regular file (shmem pages
are mapped to /dev/zero), even though their implication in actual memory
use is quite different.

The internal accounting currently counts shmem pages together with
regular files.  As a preparation to extend the userspace interfaces,
this patch adds MM_SHMEMPAGES counter to mm_rss_stat to account for
shmem pages separately from MM_FILEPAGES.  The next patch will expose it
to userspace - this patch doesn't change the exported values yet, by
adding up MM_SHMEMPAGES to MM_FILEPAGES at places where MM_FILEPAGES was
used before.  The only user-visible change after this patch is the OOM
killer message that separates the reported "shmem-rss" from "file-rss".

[vbabka@suse.cz: forward-porting, tweak changelog]
Signed-off-by: Jerome Marchand <jmarchan@redhat.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-14 16:00:49 -08:00
Dominik Dingel a3a92c31bf KVM: s390: fix mismatch between user and in-kernel guest limit
While the userspace interface requests the maximum size the gmap code
expects to get a maximum address.

This error resulted in bigger page tables than necessary for some guest
sizes, e.g. a 2GB guest used 3 levels instead of 2.

At the same time we introduce KVM_S390_NO_MEM_LIMIT, which allows in a
bright future that a guest spans the complete 64 bit address space.

We also switch to TASK_MAX_SIZE for the initial memory size, this is a
cosmetic change as the previous size also resulted in a 4 level pagetable
creation.

Reported-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Dominik Dingel <dingel@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2015-12-15 17:08:21 +01:00