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  1. May 26, 2015
  2. Apr 30, 2015
    • Michael Ellerman's avatar
      Revert "powerpc/tm: Abort syscalls in active transactions" · 68fc378c
      Michael Ellerman authored
      
      
      This reverts commit feba4036.
      
      Although the principle of this change is good, the implementation has a
      few issues.
      
      Firstly we can sometimes fail to abort a syscall because r12 may have
      been clobbered by C code if we went down the virtual CPU accounting
      path, or if syscall tracing was enabled.
      
      Secondly we have decided that it is safer to abort the syscall even
      earlier in the syscall entry path, so that we avoid the syscall tracing
      path when we are transactional.
      
      So that we have time to thoroughly test those changes we have decided to
      revert this for this merge window and will merge the fixed version in
      the next window.
      
      NB. Rather than reverting the selftest we just drop tm-syscall from
      TEST_PROGS so that it's not run by default.
      
      Fixes: feba4036 ("powerpc/tm: Abort syscalls in active transactions")
      Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
      68fc378c
  3. Apr 21, 2015
    • Paul Mackerras's avatar
      KVM: PPC: Book3S HV: Translate kvmhv_commence_exit to C · eddb60fb
      Paul Mackerras authored
      
      
      This replaces the assembler code for kvmhv_commence_exit() with C code
      in book3s_hv_builtin.c.  It also moves the IPI sending code that was
      in book3s_hv_rm_xics.c into a new kvmhv_rm_send_ipi() function so it
      can be used by kvmhv_commence_exit() as well as icp_rm_set_vcpu_irq().
      
      Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
      Signed-off-by: default avatarAlexander Graf <agraf@suse.de>
      eddb60fb
    • Paul Mackerras's avatar
      KVM: PPC: Book3S HV: Use bitmap of active threads rather than count · 7d6c40da
      Paul Mackerras authored
      
      
      Currently, the entry_exit_count field in the kvmppc_vcore struct
      contains two 8-bit counts, one of the threads that have started entering
      the guest, and one of the threads that have started exiting the guest.
      This changes it to an entry_exit_map field which contains two bitmaps
      of 8 bits each.  The advantage of doing this is that it gives us a
      bitmap of which threads need to be signalled when exiting the guest.
      That means that we no longer need to use the trick of setting the
      HDEC to 0 to pull the other threads out of the guest, which led in
      some cases to a spurious HDEC interrupt on the next guest entry.
      
      Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
      Signed-off-by: default avatarAlexander Graf <agraf@suse.de>
      7d6c40da
    • Paul Mackerras's avatar
      KVM: PPC: Book3S HV: Get rid of vcore nap_count and n_woken · 5d5b99cd
      Paul Mackerras authored
      
      
      We can tell when a secondary thread has finished running a guest by
      the fact that it clears its kvm_hstate.kvm_vcpu pointer, so there
      is no real need for the nap_count field in the kvmppc_vcore struct.
      This changes kvmppc_wait_for_nap to poll the kvm_hstate.kvm_vcpu
      pointers of the secondary threads rather than polling vc->nap_count.
      Besides reducing the size of the kvmppc_vcore struct by 8 bytes,
      this also means that we can tell which secondary threads have got
      stuck and thus print a more informative error message.
      
      Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
      Signed-off-by: default avatarAlexander Graf <agraf@suse.de>
      5d5b99cd
    • Paul Mackerras's avatar
      KVM: PPC: Book3S HV: Move vcore preemption point up into kvmppc_run_vcpu · 25fedfca
      Paul Mackerras authored
      
      
      Rather than calling cond_resched() in kvmppc_run_core() before doing
      the post-processing for the vcpus that we have just run (that is,
      calling kvmppc_handle_exit_hv(), kvmppc_set_timer(), etc.), we now do
      that post-processing before calling cond_resched(), and that post-
      processing is moved out into its own function, post_guest_process().
      
      The reschedule point is now in kvmppc_run_vcpu() and we define a new
      vcore state, VCORE_PREEMPT, to indicate that that the vcore's runner
      task is runnable but not running.  (Doing the reschedule with the
      vcore in VCORE_INACTIVE state would be bad because there are potentially
      other vcpus waiting for the runner in kvmppc_wait_for_exec() which
      then wouldn't get woken up.)
      
      Also, we make use of the handy cond_resched_lock() function, which
      unlocks and relocks vc->lock for us around the reschedule.
      
      Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
      Signed-off-by: default avatarAlexander Graf <agraf@suse.de>
      25fedfca
    • Paul Mackerras's avatar
      KVM: PPC: Book3S HV: Minor cleanups · 1f09c3ed
      Paul Mackerras authored
      
      
      * Remove unused kvmppc_vcore::n_busy field.
      * Remove setting of RMOR, since it was only used on PPC970 and the
        PPC970 KVM support has been removed.
      * Don't use r1 or r2 in setting the runlatch since they are
        conventionally reserved for other things; use r0 instead.
      * Streamline the code a little and remove the ext_interrupt_to_host
        label.
      * Add some comments about register usage.
      * hcall_try_real_mode doesn't need to be global, and can't be
        called from C code anyway.
      
      Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
      Signed-off-by: default avatarAlexander Graf <agraf@suse.de>
      1f09c3ed
    • Paul Mackerras's avatar
      KVM: PPC: Book3S HV: Simplify handling of VCPUs that need a VPA update · d911f0be
      Paul Mackerras authored
      
      
      Previously, if kvmppc_run_core() was running a VCPU that needed a VPA
      update (i.e. one of its 3 virtual processor areas needed to be pinned
      in memory so the host real mode code can update it on guest entry and
      exit), we would drop the vcore lock and do the update there and then.
      Future changes will make it inconvenient to drop the lock, so instead
      we now remove it from the list of runnable VCPUs and wake up its
      VCPU task.  This will have the effect that the VCPU task will exit
      kvmppc_run_vcpu(), go around the do loop in kvmppc_vcpu_run_hv(), and
      re-enter kvmppc_run_vcpu(), whereupon it will do the necessary call
      to kvmppc_update_vpas() and then rejoin the vcore.
      
      The one complication is that the runner VCPU (whose VCPU task is the
      current task) might be one of the ones that gets removed from the
      runnable list.  In that case we just return from kvmppc_run_core()
      and let the code in kvmppc_run_vcpu() wake up another VCPU task to be
      the runner if necessary.
      
      This all means that the VCORE_STARTING state is no longer used, so we
      remove it.
      
      Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
      Signed-off-by: default avatarAlexander Graf <agraf@suse.de>
      d911f0be
    • Paul Mackerras's avatar
      KVM: PPC: Book3S HV: Accumulate timing information for real-mode code · b6c295df
      Paul Mackerras authored
      
      
      This reads the timebase at various points in the real-mode guest
      entry/exit code and uses that to accumulate total, minimum and
      maximum time spent in those parts of the code.  Currently these
      times are accumulated per vcpu in 5 parts of the code:
      
      * rm_entry - time taken from the start of kvmppc_hv_entry() until
        just before entering the guest.
      * rm_intr - time from when we take a hypervisor interrupt in the
        guest until we either re-enter the guest or decide to exit to the
        host.  This includes time spent handling hcalls in real mode.
      * rm_exit - time from when we decide to exit the guest until the
        return from kvmppc_hv_entry().
      * guest - time spend in the guest
      * cede - time spent napping in real mode due to an H_CEDE hcall
        while other threads in the same vcore are active.
      
      These times are exposed in debugfs in a directory per vcpu that
      contains a file called "timings".  This file contains one line for
      each of the 5 timings above, with the name followed by a colon and
      4 numbers, which are the count (number of times the code has been
      executed), the total time, the minimum time, and the maximum time,
      all in nanoseconds.
      
      The overhead of the extra code amounts to about 30ns for an hcall that
      is handled in real mode (e.g. H_SET_DABR), which is about 25%.  Since
      production environments may not wish to incur this overhead, the new
      code is conditional on a new config symbol,
      CONFIG_KVM_BOOK3S_HV_EXIT_TIMING.
      
      Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
      Signed-off-by: default avatarAlexander Graf <agraf@suse.de>
      b6c295df
    • Paul Mackerras's avatar
      KVM: PPC: Book3S HV: Create debugfs file for each guest's HPT · e23a808b
      Paul Mackerras authored
      
      
      This creates a debugfs directory for each HV guest (assuming debugfs
      is enabled in the kernel config), and within that directory, a file
      by which the contents of the guest's HPT (hashed page table) can be
      read.  The directory is named vmnnnn, where nnnn is the PID of the
      process that created the guest.  The file is named "htab".  This is
      intended to help in debugging problems in the host's management
      of guest memory.
      
      The contents of the file consist of a series of lines like this:
      
        3f48 4000d032bf003505 0000000bd7ff1196 00000003b5c71196
      
      The first field is the index of the entry in the HPT, the second and
      third are the HPT entry, so the third entry contains the real page
      number that is mapped by the entry if the entry's valid bit is set.
      The fourth field is the guest's view of the second doubleword of the
      entry, so it contains the guest physical address.  (The format of the
      second through fourth fields are described in the Power ISA and also
      in arch/powerpc/include/asm/mmu-hash64.h.)
      
      Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
      Signed-off-by: default avatarAlexander Graf <agraf@suse.de>
      e23a808b
    • Aneesh Kumar K.V's avatar
      KVM: PPC: Book3S HV: Add helpers for lock/unlock hpte · a4bd6eb0
      Aneesh Kumar K.V authored
      
      
      This adds helper routines for locking and unlocking HPTEs, and uses
      them in the rest of the code.  We don't change any locking rules in
      this patch.
      
      Signed-off-by: default avatarAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
      Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
      Signed-off-by: default avatarAlexander Graf <agraf@suse.de>
      a4bd6eb0
    • Aneesh Kumar K.V's avatar
      KVM: PPC: Book3S HV: Remove RMA-related variables from code · 31037eca
      Aneesh Kumar K.V authored
      
      
      We don't support real-mode areas now that 970 support is removed.
      Remove the remaining details of rma from the code.  Also rename
      rma_setup_done to hpte_setup_done to better reflect the changes.
      
      Signed-off-by: default avatarAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
      Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
      Signed-off-by: default avatarAlexander Graf <agraf@suse.de>
      31037eca
    • Michael Ellerman's avatar
      KVM: PPC: Book3S HV: Add fast real-mode H_RANDOM implementation. · e928e9cb
      Michael Ellerman authored
      
      
      Some PowerNV systems include a hardware random-number generator.
      This HWRNG is present on POWER7+ and POWER8 chips and is capable of
      generating one 64-bit random number every microsecond.  The random
      numbers are produced by sampling a set of 64 unstable high-frequency
      oscillators and are almost completely entropic.
      
      PAPR defines an H_RANDOM hypercall which guests can use to obtain one
      64-bit random sample from the HWRNG.  This adds a real-mode
      implementation of the H_RANDOM hypercall.  This hypercall was
      implemented in real mode because the latency of reading the HWRNG is
      generally small compared to the latency of a guest exit and entry for
      all the threads in the same virtual core.
      
      Userspace can detect the presence of the HWRNG and the H_RANDOM
      implementation by querying the KVM_CAP_PPC_HWRNG capability.  The
      H_RANDOM hypercall implementation will only be invoked when the guest
      does an H_RANDOM hypercall if userspace first enables the in-kernel
      H_RANDOM implementation using the KVM_CAP_PPC_ENABLE_HCALL capability.
      
      Signed-off-by: default avatarMichael Ellerman <michael@ellerman.id.au>
      Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
      Signed-off-by: default avatarAlexander Graf <agraf@suse.de>
      e928e9cb
    • David Gibson's avatar
      kvmppc: Implement H_LOGICAL_CI_{LOAD,STORE} in KVM · 99342cf8
      David Gibson authored
      
      
      On POWER, storage caching is usually configured via the MMU - attributes
      such as cache-inhibited are stored in the TLB and the hashed page table.
      
      This makes correctly performing cache inhibited IO accesses awkward when
      the MMU is turned off (real mode).  Some CPU models provide special
      registers to control the cache attributes of real mode load and stores but
      this is not at all consistent.  This is a problem in particular for SLOF,
      the firmware used on KVM guests, which runs entirely in real mode, but
      which needs to do IO to load the kernel.
      
      To simplify this qemu implements two special hypercalls, H_LOGICAL_CI_LOAD
      and H_LOGICAL_CI_STORE which simulate a cache-inhibited load or store to
      a logical address (aka guest physical address).  SLOF uses these for IO.
      
      However, because these are implemented within qemu, not the host kernel,
      these bypass any IO devices emulated within KVM itself.  The simplest way
      to see this problem is to attempt to boot a KVM guest from a virtio-blk
      device with iothread / dataplane enabled.  The iothread code relies on an
      in kernel implementation of the virtio queue notification, which is not
      triggered by the IO hcalls, and so the guest will stall in SLOF unable to
      load the guest OS.
      
      This patch addresses this by providing in-kernel implementations of the
      2 hypercalls, which correctly scan the KVM IO bus.  Any access to an
      address not handled by the KVM IO bus will cause a VM exit, hitting the
      qemu implementation as before.
      
      Note that a userspace change is also required, in order to enable these
      new hcall implementations with KVM_CAP_PPC_ENABLE_HCALL.
      
      Signed-off-by: default avatarDavid Gibson <david@gibson.dropbear.id.au>
      [agraf: fix compilation]
      Signed-off-by: default avatarAlexander Graf <agraf@suse.de>
      99342cf8
  4. Apr 17, 2015
  5. Apr 14, 2015
    • Kees Cook's avatar
      mm: fold arch_randomize_brk into ARCH_HAS_ELF_RANDOMIZE · 204db6ed
      Kees Cook authored
      
      
      The arch_randomize_brk() function is used on several architectures,
      even those that don't support ET_DYN ASLR. To avoid bulky extern/#define
      tricks, consolidate the support under CONFIG_ARCH_HAS_ELF_RANDOMIZE for
      the architectures that support it, while still handling CONFIG_COMPAT_BRK.
      
      Signed-off-by: default avatarKees Cook <keescook@chromium.org>
      Cc: Hector Marco-Gisbert <hecmargi@upv.es>
      Cc: Russell King <linux@arm.linux.org.uk>
      Reviewed-by: default avatarIngo Molnar <mingo@kernel.org>
      Cc: Catalin Marinas <catalin.marinas@arm.com>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: Ralf Baechle <ralf@linux-mips.org>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Michael Ellerman <mpe@ellerman.id.au>
      Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Cc: Alexander Viro <viro@zeniv.linux.org.uk>
      Cc: Oleg Nesterov <oleg@redhat.com>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Cc: "David A. Long" <dave.long@linaro.org>
      Cc: Andrey Ryabinin <a.ryabinin@samsung.com>
      Cc: Arun Chandran <achandran@mvista.com>
      Cc: Yann Droneaud <ydroneaud@opteya.com>
      Cc: Min-Hua Chen <orca.chen@gmail.com>
      Cc: Paul Burton <paul.burton@imgtec.com>
      Cc: Alex Smith <alex@alex-smith.me.uk>
      Cc: Markos Chandras <markos.chandras@imgtec.com>
      Cc: Vineeth Vijayan <vvijayan@mvista.com>
      Cc: Jeff Bailey <jeffbailey@google.com>
      Cc: Michael Holzheu <holzheu@linux.vnet.ibm.com>
      Cc: Ben Hutchings <ben@decadent.org.uk>
      Cc: Behan Webster <behanw@converseincode.com>
      Cc: Ismael Ripoll <iripoll@upv.es>
      Cc: Jan-Simon Mller <dl9pf@gmx.de>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      204db6ed
  6. Apr 12, 2015
  7. Apr 11, 2015
  8. Apr 10, 2015
  9. Apr 07, 2015
  10. Apr 01, 2015
    • Kevin Hao's avatar
      powerpc: book3e_64: fix the align size for paca_struct · 016f8cf0
      Kevin Hao authored
      
      
      All the cache line size of the current book3e 64bit SoCs are 64 bytes.
      So we should use this size to align the member of paca_struct.
      This only change the paca_struct's members which are private to book3e
      CPUs, and should not have any effect to book3s ones. With this, we save
      192 bytes. Also change it to __aligned(size) since it is preferred over
      __attribute__((aligned(size))).
      
      Before:
      	/* size: 1920, cachelines: 30, members: 46 */
      	/* sum members: 1667, holes: 6, sum holes: 141 */
      	/* padding: 112 */
      
      After:
      	/* size: 1728, cachelines: 27, members: 46 */
      	/* sum members: 1667, holes: 4, sum holes: 13 */
      	/* padding: 48 */
      
      Signed-off-by: default avatarKevin Hao <haokexin@gmail.com>
      Signed-off-by: default avatarScott Wood <scottwood@freescale.com>
      016f8cf0
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