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2014-06-04hugetlb: restrict hugepage_migration_support() to x86_64Naoya Horiguchi
Currently hugepage migration is available for all archs which support pmd-level hugepage, but testing is done only for x86_64 and there're bugs for other archs. So to avoid breaking such archs, this patch limits the availability strictly to x86_64 until developers of other archs get interested in enabling this feature. Simply disabling hugepage migration on non-x86_64 archs is not enough to fix the reported problem where sys_move_pages() hits the BUG_ON() in follow_page(FOLL_GET), so let's fix this by checking if hugepage migration is supported in vma_migratable(). Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Reported-by: Michael Ellerman <mpe@ellerman.id.au> Tested-by: Michael Ellerman <mpe@ellerman.id.au> Acked-by: Hugh Dickins <hughd@google.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Tony Luck <tony.luck@intel.com> Cc: Russell King <rmk@arm.linux.org.uk> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: David Miller <davem@davemloft.net> Cc: <stable@vger.kernel.org> [3.12+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm into nextLinus Torvalds
Pull KVM updates from Paolo Bonzini: "At over 200 commits, covering almost all supported architectures, this was a pretty active cycle for KVM. Changes include: - a lot of s390 changes: optimizations, support for migration, GDB support and more - ARM changes are pretty small: support for the PSCI 0.2 hypercall interface on both the guest and the host (the latter acked by Catalin) - initial POWER8 and little-endian host support - support for running u-boot on embedded POWER targets - pretty large changes to MIPS too, completing the userspace interface and improving the handling of virtualized timer hardware - for x86, a larger set of changes is scheduled for 3.17. Still, we have a few emulator bugfixes and support for running nested fully-virtualized Xen guests (para-virtualized Xen guests have always worked). And some optimizations too. The only missing architecture here is ia64. It's not a coincidence that support for KVM on ia64 is scheduled for removal in 3.17" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (203 commits) KVM: add missing cleanup_srcu_struct KVM: PPC: Book3S PR: Rework SLB switching code KVM: PPC: Book3S PR: Use SLB entry 0 KVM: PPC: Book3S HV: Fix machine check delivery to guest KVM: PPC: Book3S HV: Work around POWER8 performance monitor bugs KVM: PPC: Book3S HV: Make sure we don't miss dirty pages KVM: PPC: Book3S HV: Fix dirty map for hugepages KVM: PPC: Book3S HV: Put huge-page HPTEs in rmap chain for base address KVM: PPC: Book3S HV: Fix check for running inside guest in global_invalidates() KVM: PPC: Book3S: Move KVM_REG_PPC_WORT to an unused register number KVM: PPC: Book3S: Add ONE_REG register names that were missed KVM: PPC: Add CAP to indicate hcall fixes KVM: PPC: MPIC: Reset IRQ source private members KVM: PPC: Graciously fail broken LE hypercalls PPC: ePAPR: Fix hypercall on LE guest KVM: PPC: BOOK3S: Remove open coded make_dsisr in alignment handler KVM: PPC: BOOK3S: Always use the saved DAR value PPC: KVM: Make NX bit available with magic page KVM: PPC: Disable NX for old magic page using guests KVM: PPC: BOOK3S: HV: Add mixed page-size support for guest ...
2014-05-20s390: split TIF bits into CIF, PIF and TIF bitsMartin Schwidefsky
The oi and ni instructions used in entry[64].S to set and clear bits in the thread-flags are not guaranteed to be atomic in regard to other CPUs. Split the TIF bits into CPU, pt_regs and thread-info specific bits. Updates on the TIF bits are done with atomic instructions, updates on CPU and pt_regs bits are done with non-atomic instructions. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2014-05-20s390/uaccess: simplify control register updatesMartin Schwidefsky
Always switch to the kernel ASCE in switch_mm. Load the secondary space ASCE in finish_arch_post_lock_switch after checking that any pending page table operations have completed. The primary ASCE is loaded in entry[64].S. With this the update_primary_asce call can be removed from the switch_to macro and from the start of switch_mm function. Remove the load_primary argument from update_user_asce/clear_user_asce, rename update_user_asce to set_user_asce and rename update_primary_asce to load_kernel_asce. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2014-05-20s390/cmma: remove "cmma disable" code in case of dump againHeiko Carstens
This is not necessary anymore, since the offending code is gone with the conversion to the memblock code. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>- Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2014-05-20s390/mm: Convert bootmem to memblockPhilipp Hachtmann
The original bootmem allocator is getting replaced by memblock. To cover the needs of the s390 kdump implementation the physical memory list is used. With this patch the bootmem allocator and its bitmaps are completely removed from s390. Signed-off-by: Philipp Hachtmann <phacht@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2014-05-16KVM: s390: correct locking for s390_enable_skeyMartin Schwidefsky
Use the mm semaphore to serialize multiple invocations of s390_enable_skey. The second CPU faulting on a storage key operation needs to wait for the completion of the page table update. Taking the mm semaphore writable has the positive side-effect that it prevents any host faults from taking place which does have implications on keys vs PGSTE. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2014-04-22KVM: s390/mm: new gmap_test_and_clear_dirty functionDominik Dingel
For live migration kvm needs to test and clear the dirty bit of guest pages. That for is ptep_test_and_clear_user_dirty, to be sure we are not racing with other code, we protect the pte. This needs to be done within the architecture memory management code. Signed-off-by: Dominik Dingel <dingel@linux.vnet.ibm.com> Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2014-04-22KVM: s390/mm: use software dirty bit detection for user dirty trackingMartin Schwidefsky
Switch the user dirty bit detection used for migration from the hardware provided host change-bit in the pgste to a fault based detection method. This reduced the dependency of the host from the storage key to a point where it becomes possible to enable the RCP bypass for KVM guests. The fault based dirty detection will only indicate changes caused by accesses via the guest address space. The hardware based method can detect all changes, even those caused by I/O or accesses via the kernel page table. The KVM/qemu code needs to take this into account. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Dominik Dingel <dingel@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2014-04-22KVM: s390: Allow skeys to be enabled for the current processDominik Dingel
Introduce a new function s390_enable_skey(), which enables storage key handling via setting the use_skey flag in the mmu context. This function is only useful within the context of kvm. Note that enabling storage keys will cause a one-time hickup when walking the page table; however, it saves us special effort for cases like clear reset while making it possible for us to be architecture conform. s390_enable_skey() takes the page table lock to prevent reseting storage keys triggered from multiple vcpus. Signed-off-by: Dominik Dingel <dingel@linux.vnet.ibm.com> Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2014-04-22KVM: s390: Clear storage keysDominik Dingel
page_table_reset_pgste() already does a complete page table walk to reset the pgste. Enhance it to initialize the storage keys to PAGE_DEFAULT_KEY if requested by the caller. This will be used for lazy storage key handling. Also provide an empty stub for !CONFIG_PGSTE Lets adopt the current code (diag 308) to not clear the keys. Signed-off-by: Dominik Dingel <dingel@linux.vnet.ibm.com> Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2014-04-09s390/mm: print control registers and page table walk on crashHeiko Carstens
Print extra debugging information to the console if the kernel or a user space process crashed (with user space debugging enabled): - contents of control register 7 and 13 - failing address and translation exception identification - page table walk for the failing address Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2014-04-08Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull second set of s390 patches from Martin Schwidefsky: "The second part of Heikos uaccess rework, the page table walker for uaccess is now a thing of the past (yay!) The code change to fix the theoretical TLB flush problem allows us to add a TLB flush optimization for zEC12, this machine has new instructions that allow to do CPU local TLB flushes for single pages and for all pages of a specific address space. Plus the usual bug fixing and some more cleanup" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: s390/uaccess: rework uaccess code - fix locking issues s390/mm,tlb: optimize TLB flushing for zEC12 s390/mm,tlb: safeguard against speculative TLB creation s390/irq: Use defines for external interruption codes s390/irq: Add defines for external interruption codes s390/sclp: add timeout for queued requests kvm/s390: also set guest pages back to stable on kexec/kdump lcs: Add missing destroy_timer_on_stack() s390/tape: Add missing destroy_timer_on_stack() s390/tape: Use del_timer_sync() s390/3270: fix crash with multiple reset device requests s390/bitops,atomic: add missing memory barriers s390/zcrypt: add length check for aligned data to avoid overflow in msg-type 6
2014-04-07mm: revert "thp: make MADV_HUGEPAGE check for mm->def_flags"Alex Thorlton
The main motivation behind this patch is to provide a way to disable THP for jobs where the code cannot be modified, and using a malloc hook with madvise is not an option (i.e. statically allocated data). This patch allows us to do just that, without affecting other jobs running on the system. We need to do this sort of thing for jobs where THP hurts performance, due to the possibility of increased remote memory accesses that can be created by situations such as the following: When you touch 1 byte of an untouched, contiguous 2MB chunk, a THP will be handed out, and the THP will be stuck on whatever node the chunk was originally referenced from. If many remote nodes need to do work on that same chunk, they'll be making remote accesses. With THP disabled, 4K pages can be handed out to separate nodes as they're needed, greatly reducing the amount of remote accesses to memory. This patch is based on some of my work combined with some suggestions/patches given by Oleg Nesterov. The main goal here is to add a prctl switch to allow us to disable to THP on a per mm_struct basis. Here's a bit of test data with the new patch in place... First with the flag unset: # perf stat -a ./prctl_wrapper_mmv3 0 ./thp_pthread -C 0 -m 0 -c 512 -b 256g Setting thp_disabled for this task... thp_disable: 0 Set thp_disabled state to 0 Process pid = 18027 PF/ MAX MIN TOTCPU/ TOT_PF/ TOT_PF/ WSEC/ TYPE: CPUS WALL WALL SYS USER TOTCPU CPU WALL_SEC SYS_SEC CPU NODES 512 1.120 0.060 0.000 0.110 0.110 0.000 28571428864 -9223372036854775808 55803572 23 Performance counter stats for './prctl_wrapper_mmv3_hack 0 ./thp_pthread -C 0 -m 0 -c 512 -b 256g': 273719072.841402 task-clock # 641.026 CPUs utilized [100.00%] 1,008,986 context-switches # 0.000 M/sec [100.00%] 7,717 CPU-migrations # 0.000 M/sec [100.00%] 1,698,932 page-faults # 0.000 M/sec 355,222,544,890,379 cycles # 1.298 GHz [100.00%] 536,445,412,234,588 stalled-cycles-frontend # 151.02% frontend cycles idle [100.00%] 409,110,531,310,223 stalled-cycles-backend # 115.17% backend cycles idle [100.00%] 148,286,797,266,411 instructions # 0.42 insns per cycle # 3.62 stalled cycles per insn [100.00%] 27,061,793,159,503 branches # 98.867 M/sec [100.00%] 1,188,655,196 branch-misses # 0.00% of all branches 427.001706337 seconds time elapsed Now with the flag set: # perf stat -a ./prctl_wrapper_mmv3 1 ./thp_pthread -C 0 -m 0 -c 512 -b 256g Setting thp_disabled for this task... thp_disable: 1 Set thp_disabled state to 1 Process pid = 144957 PF/ MAX MIN TOTCPU/ TOT_PF/ TOT_PF/ WSEC/ TYPE: CPUS WALL WALL SYS USER TOTCPU CPU WALL_SEC SYS_SEC CPU NODES 512 0.620 0.260 0.250 0.320 0.570 0.001 51612901376 128000000000 100806448 23 Performance counter stats for './prctl_wrapper_mmv3_hack 1 ./thp_pthread -C 0 -m 0 -c 512 -b 256g': 138789390.540183 task-clock # 641.959 CPUs utilized [100.00%] 534,205 context-switches # 0.000 M/sec [100.00%] 4,595 CPU-migrations # 0.000 M/sec [100.00%] 63,133,119 page-faults # 0.000 M/sec 147,977,747,269,768 cycles # 1.066 GHz [100.00%] 200,524,196,493,108 stalled-cycles-frontend # 135.51% frontend cycles idle [100.00%] 105,175,163,716,388 stalled-cycles-backend # 71.07% backend cycles idle [100.00%] 180,916,213,503,160 instructions # 1.22 insns per cycle # 1.11 stalled cycles per insn [100.00%] 26,999,511,005,868 branches # 194.536 M/sec [100.00%] 714,066,351 branch-misses # 0.00% of all branches 216.196778807 seconds time elapsed As with previous versions of the patch, We're getting about a 2x performance increase here. Here's a link to the test case I used, along with the little wrapper to activate the flag: http://oss.sgi.com/projects/memtests/thp_pthread_mmprctlv3.tar.gz This patch (of 3): Revert commit 8e72033f2a48 and add in code to fix up any issues caused by the revert. The revert is necessary because hugepage_madvise would return -EINVAL when VM_NOHUGEPAGE is set, which will break subsequent chunks of this patch set. Here's a snip of an e-mail from Gerald detailing the original purpose of this code, and providing justification for the revert: "The intent of commit 8e72033f2a48 was to guard against any future programming errors that may result in an madvice(MADV_HUGEPAGE) on guest mappings, which would crash the kernel. Martin suggested adding the bit to arch/s390/mm/pgtable.c, if 8e72033f2a48 was to be reverted, because that check will also prevent a kernel crash in the case described above, it will now send a SIGSEGV instead. This would now also allow to do the madvise on other parts, if needed, so it is a more flexible approach. One could also say that it would have been better to do it this way right from the beginning..." Signed-off-by: Alex Thorlton <athorlton@sgi.com> Suggested-by: Oleg Nesterov <oleg@redhat.com> Tested-by: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Rik van Riel <riel@redhat.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-03s390/uaccess: rework uaccess code - fix locking issuesHeiko Carstens
The current uaccess code uses a page table walk in some circumstances, e.g. in case of the in atomic futex operations or if running on old hardware which doesn't support the mvcos instruction. However it turned out that the page table walk code does not correctly lock page tables when accessing page table entries. In other words: a different cpu may invalidate a page table entry while the current cpu inspects the pte. This may lead to random data corruption. Adding correct locking however isn't trivial for all uaccess operations. Especially copy_in_user() is problematic since that requires to hold at least two locks, but must be protected against ABBA deadlock when a different cpu also performs a copy_in_user() operation. So the solution is a different approach where we change address spaces: User space runs in primary address mode, or access register mode within vdso code, like it currently already does. The kernel usually also runs in home space mode, however when accessing user space the kernel switches to primary or secondary address mode if the mvcos instruction is not available or if a compare-and-swap (futex) instruction on a user space address is performed. KVM however is special, since that requires the kernel to run in home address space while implicitly accessing user space with the sie instruction. So we end up with: User space: - runs in primary or access register mode - cr1 contains the user asce - cr7 contains the user asce - cr13 contains the kernel asce Kernel space: - runs in home space mode - cr1 contains the user or kernel asce -> the kernel asce is loaded when a uaccess requires primary or secondary address mode - cr7 contains the user or kernel asce, (changed with set_fs()) - cr13 contains the kernel asce In case of uaccess the kernel changes to: - primary space mode in case of a uaccess (copy_to_user) and uses e.g. the mvcp instruction to access user space. However the kernel will stay in home space mode if the mvcos instruction is available - secondary space mode in case of futex atomic operations, so that the instructions come from primary address space and data from secondary space In case of kvm the kernel runs in home space mode, but cr1 gets switched to contain the gmap asce before the sie instruction gets executed. When the sie instruction is finished cr1 will be switched back to contain the user asce. A context switch between two processes will always load the kernel asce for the next process in cr1. So the first exit to user space is a bit more expensive (one extra load control register instruction) than before, however keeps the code rather simple. In sum this means there is no need to perform any error prone page table walks anymore when accessing user space. The patch seems to be rather large, however it mainly removes the the page table walk code and restores the previously deleted "standard" uaccess code, with a couple of changes. The uaccess without mvcos mode can be enforced with the "uaccess_primary" kernel parameter. Reported-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2014-04-03s390/mm,tlb: optimize TLB flushing for zEC12Martin Schwidefsky
The zEC12 machines introduced the local-clearing control for the IDTE and IPTE instruction. If the control is set only the TLB of the local CPU is cleared of entries, either all entries of a single address space for IDTE, or the entry for a single page-table entry for IPTE. Without the local-clearing control the TLB flush is broadcasted to all CPUs in the configuration, which is expensive. The reset of the bit mask of the CPUs that need flushing after a non-local IDTE is tricky. As TLB entries for an address space remain in the TLB even if the address space is detached a new bit field is required to keep track of attached CPUs vs. CPUs in the need of a flush. After a non-local flush with IDTE the bit-field of attached CPUs is copied to the bit-field of CPUs in need of a flush. The ordering of operations on cpu_attach_mask, attach_count and mm_cpumask(mm) is such that an underindication in mm_cpumask(mm) is prevented but an overindication in mm_cpumask(mm) is possible. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2014-04-03s390/mm,tlb: safeguard against speculative TLB creationMartin Schwidefsky
The principles of operations states that the CPU is allowed to create TLB entries for an address space anytime while an ASCE is loaded to the control register. This is true even if the CPU is running in the kernel and the user address space is not (actively) accessed. In theory this can affect two aspects of the TLB flush logic. For full-mm flushes the ASCE of the dying process is still attached. The approach to flush first with IDTE and then just free all page tables can in theory lead to stale TLB entries. Use the batched free of page tables for the full-mm flushes as well. For operations that can have a stale ASCE in the control register, e.g. a delayed update_user_asce in switch_mm, load the kernel ASCE to prevent invalid TLBs from being created. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2014-04-03s390/irq: Use defines for external interruption codesThomas Huth
Use the new defines for external interruption codes to get rid of "magic" numbers in the s390 source code. And while we're at it, also rename the (un-)register_external_interrupt function to something shorter so that this patch does not exceed the 80 columns all over the place. Signed-off-by: Thomas Huth <thuth@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2014-04-02Merge tag 'kvm-3.15-1' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull kvm updates from Paolo Bonzini: "PPC and ARM do not have much going on this time. Most of the cool stuff, instead, is in s390 and (after a few releases) x86. ARM has some caching fixes and PPC has transactional memory support in guests. MIPS has some fixes, with more probably coming in 3.16 as QEMU will soon get support for MIPS KVM. For x86 there are optimizations for debug registers, which trigger on some Windows games, and other important fixes for Windows guests. We now expose to the guest Broadwell instruction set extensions and also Intel MPX. There's also a fix/workaround for OS X guests, nested virtualization features (preemption timer), and a couple kvmclock refinements. For s390, the main news is asynchronous page faults, together with improvements to IRQs (floating irqs and adapter irqs) that speed up virtio devices" * tag 'kvm-3.15-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (96 commits) KVM: PPC: Book3S HV: Save/restore host PMU registers that are new in POWER8 KVM: PPC: Book3S HV: Fix decrementer timeouts with non-zero TB offset KVM: PPC: Book3S HV: Don't use kvm_memslots() in real mode KVM: PPC: Book3S HV: Return ENODEV error rather than EIO KVM: PPC: Book3S: Trim top 4 bits of physical address in RTAS code KVM: PPC: Book3S HV: Add get/set_one_reg for new TM state KVM: PPC: Book3S HV: Add transactional memory support KVM: Specify byte order for KVM_EXIT_MMIO KVM: vmx: fix MPX detection KVM: PPC: Book3S HV: Fix KVM hang with CONFIG_KVM_XICS=n KVM: PPC: Book3S: Introduce hypervisor call H_GET_TCE KVM: PPC: Book3S HV: Fix incorrect userspace exit on ioeventfd write KVM: s390: clear local interrupts at cpu initial reset KVM: s390: Fix possible memory leak in SIGP functions KVM: s390: fix calculation of idle_mask array size KVM: s390: randomize sca address KVM: ioapic: reinject pending interrupts on KVM_SET_IRQCHIP KVM: Bump KVM_MAX_IRQ_ROUTES for s390 KVM: s390: irq routing for adapter interrupts. KVM: s390: adapter interrupt sources ...
2014-03-21s390/mm: remove unnecessary parameter from gmap_do_ipte_notifyDominik Dingel
Signed-off-by: Dominik Dingel <dingel@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2014-03-21s390/mm: fixing comment so that parameter name matchDominik Dingel
Signed-off-by: Dominik Dingel <dingel@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2014-03-04Merge tag 'kvm-for-3.15-1' of ↵Paolo Bonzini
git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms into kvm-next
2014-02-24s390/uaccess: remove copy_from_user_real()Heiko Carstens
There is no user left, so remove it. It was also potentially broken, since the function didn't clear destination memory if copy_from_user() failed. Which would allow for information leaks. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2014-02-21s390/mm: enable split page table lock for PMD levelMartin Schwidefsky
Add the pgtable_pmd_page_ctor/pgtable_pmd_page_dtor calls to the pmd allocation and free functions and enable ARCH_ENABLE_SPLIT_PMD_PTLOCK for 64 bit. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2014-02-21s390/kvm: set guest page states to stable on re-iplMartin Schwidefsky
The guest page state needs to be reset to stable for all pages on initial program load via diagnose 0x308. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2014-02-21s390/kvm: support collaborative memory managementKonstantin Weitz
This patch enables Collaborative Memory Management (CMM) for kvm on s390. CMM allows the guest to inform the host about page usage (see arch/s390/mm/cmm.c). The host uses this information to avoid swapping in unused pages in the page fault handler. Further, a CPU provided list of unused invalid pages is processed to reclaim swap space of not yet accessed unused pages. [ Martin Schwidefsky: patch reordering and cleanup ] Signed-off-by: Konstantin Weitz <konstantin.weitz@gmail.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2014-02-21s390/uaccess: consistent typesHeiko Carstens
The types 'size_t' and 'unsigned long' have been used randomly for the uaccess functions. This looks rather confusing. So let's change all functions to use unsigned long instead and get rid of size_t in order to have a consistent interface. The only exception is strncpy_from_user() which uses 'long' since it may return a signed value (-EFAULT). Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2014-02-04s390/dump: Fix dump memory detectionMichael Holzheu
Dumps created by kdump or zfcpdump can contain invalid memory holes when dumping z/VM systems that have memory pressure. For example: # zgetdump -i /proc/vmcore. Memory map: 0000000000000000 - 0000000000bfffff (12 MB) 0000000000e00000 - 00000000014fffff (7 MB) 000000000bd00000 - 00000000f3bfffff (3711 MB) The memory detection function find_memory_chunks() issues tprot to find valid memory chunks. In case of CMM it can happen that pages are marked as unstable via set_page_unstable() in arch_free_page(). If z/VM has released that pages, tprot returns -EFAULT and indicates a memory hole. So fix this and switch off CMM in case of kdump or zfcpdump. Cc: <stable@vger.kernel.org> Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2014-01-30KVM: s390: Add FAULT_FLAG_RETRY_NOWAIT for guest faultDominik Dingel
In the case of a fault, we will retry to exit sie64 but with gmap fault indication for this thread set. This makes it possible to handle async page faults. Based on a patch from Martin Schwidefsky. Signed-off-by: Dominik Dingel <dingel@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2014-01-16s390: Fix misspellings using 'codespell' toolHendrik Brueckner
Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2013-11-15s390: handle pgtable_page_ctor() failKirill A. Shutemov
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-15mm, thp: do not access mm->pmd_huge_pte directlyKirill A. Shutemov
Currently mm->pmd_huge_pte protected by page table lock. It will not work with split lock. We have to have per-pmd pmd_huge_pte for proper access serialization. For now, let's just introduce wrapper to access mm->pmd_huge_pte. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Tested-by: Alex Thorlton <athorlton@sgi.com> Cc: Alex Thorlton <athorlton@sgi.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: "Eric W . Biederman" <ebiederm@xmission.com> Cc: "Paul E . McKenney" <paulmck@linux.vnet.ibm.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andi Kleen <ak@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Dave Jones <davej@redhat.com> Cc: David Howells <dhowells@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kees Cook <keescook@chromium.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Robin Holt <robinmholt@gmail.com> Cc: Sedat Dilek <sedat.dilek@gmail.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-13s390/mmap: randomize mmap base for bottom up directionHeiko Carstens
Implement mmap base randomization for the bottom up direction, so ASLR works for both mmap layouts on s390. See also commit df54d6fa5427 ("x86 get_unmapped_area(): use proper mmap base for bottom-up direction"). Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Radu Caragea <sinaelgl@gmail.com> Cc: Michel Lespinasse <walken@google.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-04s390/mm,tlb: correct tlb flush on page table upgradeMartin Schwidefsky
The IDTE instruction used to flush TLB entries for a specific address space uses the address-space-control element (ASCE) to identify affected TLB entries. The upgrade of a page table adds a new top level page table which changes the ASCE. The TLB entries associated with the old ASCE need to be flushed and the ASCE for the address space needs to be replaced synchronously on all CPUs which currently use it. The concept of a lazy ASCE update with an exception handler is broken. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2013-10-31s390/mm: page_table_realloc returns failureDominik Dingel
There is a possible race between setting has_pgste and reallocation of the page_table, change the order to fix this. Also page_table_alloc_pgste can fail, in that case we need to backpropagte this as -ENOMEM to the caller of page_table_realloc. Based on a patch by Christian Borntraeger <borntraeger@de.ibm.com>. Reviewed-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Dominik Dingel <dingel@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2013-10-28s390: convert use of typedef ctl_table to struct ctl_tableJoe Perches
This typedef is unnecessary and should just be removed. Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2013-10-24s390/cmm: make copy_from_user() invocation provably correctHeiko Carstens
Get rid of these two warnings: In function 'copy_from_user', inlined from 'cmm_timeout_handler' at arch/s390/mm/cmm.c:310: uaccess.h:303: warning: call to 'copy_from_user_overflow' declared with attribute warning: copy_from_user() buffer size is not provably correct In function 'copy_from_user', inlined from 'cmm_pages_handler' at arch/s390/mm/cmm.c:270: uaccess.h:303: warning: call to 'copy_from_user_overflow' declared with attribute warning: copy_from_user() buffer size is not provably correct Change the "len" type to unsigned int, so we can make sure that there is no buffer overflow. This also generates less code. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2013-10-24s390/gup: handle zero nr_pages case correctlyHeiko Carstens
If [__]get_user_pages_fast() gets called with nr_pages == 0, the current code would walk the page tables and pin as many pages until the first invalid pte (or the kernel crashed while writing struct page pointers to the pages array). So let's handle at least the nr_pages == 0 case correctly and exit early. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2013-10-24s390/gup: reduce code duplication between [__]get_user_pages_fast functionsHeiko Carstens
Just call __get_user_pages_fast() from get_user_pages_fast() like powerpc. This saves a lot of duplicated code. Reviewed-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2013-10-24s390/mm: do not initialize storage keysMartin Schwidefsky
With dirty and referenced bits implemented in software it is unnecessary to initialize the storage key for every page. With this patch not a single storage key operation is done for a system that does not use KVM. For KVM set_pte_at/pgste_set_key will do the initialization for the guest view of the storage key when the mapping for the page is established in the host. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2013-10-24s390/uaccess: always run the kernel in home spaceMartin Schwidefsky
Simplify the uaccess code by removing the user_mode=home option. The kernel will now always run in the home space mode. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2013-09-12arch: mm: pass userspace fault flag to generic fault handlerJohannes Weiner
Unlike global OOM handling, memory cgroup code will invoke the OOM killer in any OOM situation because it has no way of telling faults occuring in kernel context - which could be handled more gracefully - from user-triggered faults. Pass a flag that identifies faults originating in user space from the architecture-specific fault handlers to generic code so that memcg OOM handling can be improved. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Michal Hocko <mhocko@suse.cz> Cc: David Rientjes <rientjes@google.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: azurIt <azurit@pobox.sk> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11mm: migrate: check movability of hugepage in unmap_and_move_huge_page()Naoya Horiguchi
Currently hugepage migration works well only for pmd-based hugepages (mainly due to lack of testing,) so we had better not enable migration of other levels of hugepages until we are ready for it. Some users of hugepage migration (mbind, move_pages, and migrate_pages) do page table walk and check pud/pmd_huge() there, so they are safe. But the other users (softoffline and memory hotremove) don't do this, so without this patch they can try to migrate unexpected types of hugepages. To prevent this, we introduce hugepage_migration_support() as an architecture dependent check of whether hugepage are implemented on a pmd basis or not. And on some architecture multiple sizes of hugepages are available, so hugepage_migration_support() also checks hugepage size. Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Hillf Danton <dhillf@gmail.com> Cc: Wanpeng Li <liwanp@linux.vnet.ibm.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Hugh Dickins <hughd@google.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: Rik van Riel <riel@redhat.com> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull more s390 updates from Heiko Carstens: "This includes one bpf/jit bug fix where the jit compiler could sometimes write generated code out of bounds of the allocated memory area. The rest of the patches are only cleanups and minor improvements" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: s390/irq: reduce size of external interrupt handler hash array s390/compat,uid16: use current_cred() s390/ap_bus: use and-mask instead of a cast s390/ftrace: avoid pointer arithmetics with function pointers s390: make various functions static, add declarations to header files s390/compat signal: add couple of __force annotations s390/mm: add __releases()/__acquires() annotations to gmap_alloc_table() s390: keep Kconfig sorted s390/irq: rework irq subclass handling s390/irq: use hlists for external interrupt handler array s390/dumpstack: convert print_symbol to %pSR s390/perf: Remove print_hex_dump_bytes() debug output s390: update defconfig s390/bpf,jit: fix address randomization
2013-09-07s390: make various functions static, add declarations to header filesHeiko Carstens
Make various functions static, add declarations to header files to fix a couple of sparse findings. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2013-09-07s390/mm: add __releases()/__acquires() annotations to gmap_alloc_table()Heiko Carstens
Let sparse not incorrectly complain about unbalanced locking. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2013-09-04Merge branch 'next' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull KVM updates from Gleb Natapov: "The highlights of the release are nested EPT and pv-ticketlocks support (hypervisor part, guest part, which is most of the code, goes through tip tree). Apart of that there are many fixes for all arches" Fix up semantic conflicts as discussed in the pull request thread.. * 'next' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (88 commits) ARM: KVM: Add newlines to panic strings ARM: KVM: Work around older compiler bug ARM: KVM: Simplify tracepoint text ARM: KVM: Fix kvm_set_pte assignment ARM: KVM: vgic: Bump VGIC_NR_IRQS to 256 ARM: KVM: Bugfix: vgic_bytemap_get_reg per cpu regs ARM: KVM: vgic: fix GICD_ICFGRn access ARM: KVM: vgic: simplify vgic_get_target_reg KVM: MMU: remove unused parameter KVM: PPC: Book3S PR: Rework kvmppc_mmu_book3s_64_xlate() KVM: PPC: Book3S PR: Make instruction fetch fallback work for system calls KVM: PPC: Book3S PR: Don't corrupt guest state when kernel uses VMX KVM: x86: update masterclock when kvmclock_offset is calculated (v2) KVM: PPC: Book3S: Fix compile error in XICS emulation KVM: PPC: Book3S PR: return appropriate error when allocation fails arch: powerpc: kvm: add signed type cast for comparation KVM: x86: add comments where MMIO does not return to the emulator KVM: vmx: count exits to userspace during invalid guest emulation KVM: rename __kvm_io_bus_sort_cmp to kvm_io_bus_cmp kvm: optimize away THP checks in kvm_is_mmio_pfn() ...
2013-09-04s390/irq: rework irq subclass handlingHeiko Carstens
Let's not add a function for every external interrupt subclass for which we need reference counting. Just have two register/unregister functions which have a subclass parameter: void irq_subclass_register(enum irq_subclass subclass); void irq_subclass_unregister(enum irq_subclass subclass); Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2013-08-29s390/mm: implement software referenced bitsMartin Schwidefsky
The last remaining use for the storage key of the s390 architecture is reference counting. The alternative is to make page table entries invalid while they are old. On access the fault handler marks the pte/pmd as young which makes the pte/pmd valid if the access rights allow read access. The pte/pmd invalidations required for software managed reference bits cost a bit of performance, on the other hand the RRBE/RRBM instructions to read and reset the referenced bits are quite expensive as well. Reviewed-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2013-08-22s390/mm: introduce ptep_flush_lazy helperMartin Schwidefsky
Isolate the logic of IDTE vs. IPTE flushing of ptes in two functions, ptep_flush_lazy and __tlb_flush_mm_lazy. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>