1. 14 Sep, 2018 3 commits
    • Olaf Hering's avatar
      xen: avoid crash in disable_hotplug_cpu · 3366cdb6
      Olaf Hering authored
      The command 'xl vcpu-set 0 0', issued in dom0, will crash dom0:
      
      BUG: unable to handle kernel NULL pointer dereference at 00000000000002d8
      PGD 0 P4D 0
      Oops: 0000 [#1] PREEMPT SMP NOPTI
      CPU: 7 PID: 65 Comm: xenwatch Not tainted 4.19.0-rc2-1.ga9462db-default #1 openSUSE Tumbleweed (unreleased)
      Hardware name: Intel Corporation S5520UR/S5520UR, BIOS S5500.86B.01.00.0050.050620101605 05/06/2010
      RIP: e030:device_offline+0x9/0xb0
      Code: 77 24 00 e9 ce fe ff ff 48 8b 13 e9 68 ff ff ff 48 8b 13 e9 29 ff ff ff 48 8b 13 e9 ea fe ff ff 90 66 66 66 66 90 41 54 55 53 <f6> 87 d8 02 00 00 01 0f 85 88 00 00 00 48 c7 c2 20 09 60 81 31 f6
      RSP: e02b:ffffc90040f27e80 EFLAGS: 00010203
      RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
      RDX: ffff8801f3800000 RSI: ffffc90040f27e70 RDI: 0000000000000000
      RBP: 0000000000000000 R08: ffffffff820e47b3 R09: 0000000000000000
      R10: 0000000000007ff0 R11: 0000000000000000 R12: ffffffff822e6d30
      R13: dead000000000200 R14: dead000000000100 R15: ffffffff8158b4e0
      FS:  00007ffa595158c0(0000) GS:ffff8801f39c0000(0000) knlGS:0000000000000000
      CS:  e033 DS: 0000 ES: 0000 CR0: 0000000080050033
      CR2: 00000000000002d8 CR3: 00000001d9602000 CR4: 0000000000002660
      Call Trace:
       handle_vcpu_hotplug_event+0xb5/0xc0
       xenwatch_thread+0x80/0x140
       ? wait_woken+0x80/0x80
       kthread+0x112/0x130
       ? kthread_create_worker_on_cpu+0x40/0x40
       ret_from_fork+0x3a/0x50
      
      This happens because handle_vcpu_hotplug_event is called twice. In the
      first iteration cpu_present is still true, in the second iteration
      cpu_present is false which causes get_cpu_device to return NULL.
      In case of cpu#0, cpu_online is apparently always true.
      
      Fix this crash by checking if the cpu can be hotplugged, which is false
      for a cpu that was just removed.
      
      Also check if the cpu was actually offlined by device_remove, otherwise
      leave the cpu_present state as it is.
      
      Rearrange to code to do all work with device_hotplug_lock held.
      Signed-off-by: default avatarOlaf Hering <olaf@aepfle.de>
      Reviewed-by: default avatarJuergen Gross <jgross@suse.com>
      Signed-off-by: default avatarBoris Ostrovsky <boris.ostrovsky@oracle.com>
      3366cdb6
    • Marek Marczykowski-Górecki's avatar
      xen/balloon: add runtime control for scrubbing ballooned out pages · 197ecb38
      Marek Marczykowski-Górecki authored
      Scrubbing pages on initial balloon down can take some time, especially
      in nested virtualization case (nested EPT is slow). When HVM/PVH guest is
      started with memory= significantly lower than maxmem=, all the extra
      pages will be scrubbed before returning to Xen. But since most of them
      weren't used at all at that point, Xen needs to populate them first
      (from populate-on-demand pool). In nested virt case (Xen inside KVM)
      this slows down the guest boot by 15-30s with just 1.5GB needed to be
      returned to Xen.
      
      Add runtime parameter to enable/disable it, to allow initially disabling
      scrubbing, then enable it back during boot (for example in initramfs).
      Such usage relies on assumption that a) most pages ballooned out during
      initial boot weren't used at all, and b) even if they were, very few
      secrets are in the guest at that time (before any serious userspace
      kicks in).
      Convert CONFIG_XEN_SCRUB_PAGES to CONFIG_XEN_SCRUB_PAGES_DEFAULT (also
      enabled by default), controlling default value for the new runtime
      switch.
      Signed-off-by: default avatarMarek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
      Reviewed-by: default avatarJuergen Gross <jgross@suse.com>
      Signed-off-by: default avatarBoris Ostrovsky <boris.ostrovsky@oracle.com>
      197ecb38
    • Vitaly Kuznetsov's avatar
      xen/manage: don't complain about an empty value in control/sysrq node · 87dffe86
      Vitaly Kuznetsov authored
      When guest receives a sysrq request from the host it acknowledges it by
      writing '\0' to control/sysrq xenstore node. This, however, make xenstore
      watch fire again but xenbus_scanf() fails to parse empty value with "%c"
      format string:
      
       sysrq: SysRq : Emergency Sync
       Emergency Sync complete
       xen:manage: Error -34 reading sysrq code in control/sysrq
      
      Ignore -ERANGE the same way we already ignore -ENOENT, empty value in
      control/sysrq is totally legal.
      Signed-off-by: default avatarVitaly Kuznetsov <vkuznets@redhat.com>
      Reviewed-by: default avatarWei Liu <wei.liu2@citrix.com>
      Signed-off-by: default avatarBoris Ostrovsky <boris.ostrovsky@oracle.com>
      87dffe86
  2. 10 Sep, 2018 1 commit
  3. 09 Sep, 2018 7 commits
  4. 08 Sep, 2018 6 commits
    • Linus Torvalds's avatar
      Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm · f8f65382
      Linus Torvalds authored
      Pull KVM fixes from Radim Krčmář:
       "ARM:
         - Fix a VFP corruption in 32-bit guest
         - Add missing cache invalidation for CoW pages
         - Two small cleanups
      
        s390:
         - Fallout from the hugetlbfs support: pfmf interpretion and locking
         - VSIE: fix keywrapping for nested guests
      
        PPC:
         - Fix a bug where pages might not get marked dirty, causing guest
           memory corruption on migration
         - Fix a bug causing reads from guest memory to use the wrong guest
           real address for very large HPT guests (>256G of memory), leading
           to failures in instruction emulation.
      
        x86:
         - Fix out of bound access from malicious pv ipi hypercalls
           (introduced in rc1)
         - Fix delivery of pending interrupts when entering a nested guest,
           preventing arbitrarily late injection
         - Sanitize kvm_stat output after destroying a guest
         - Fix infinite loop when emulating a nested guest page fault and
           improve the surrounding emulation code
         - Two minor cleanups"
      
      * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (28 commits)
        KVM: LAPIC: Fix pv ipis out-of-bounds access
        KVM: nVMX: Fix loss of pending IRQ/NMI before entering L2
        arm64: KVM: Remove pgd_lock
        KVM: Remove obsolete kvm_unmap_hva notifier backend
        arm64: KVM: Only force FPEXC32_EL2.EN if trapping FPSIMD
        KVM: arm/arm64: Clean dcache to PoC when changing PTE due to CoW
        KVM: s390: Properly lock mm context allow_gmap_hpage_1m setting
        KVM: s390: vsie: copy wrapping keys to right place
        KVM: s390: Fix pfmf and conditional skey emulation
        tools/kvm_stat: re-animate display of dead guests
        tools/kvm_stat: indicate dead guests as such
        tools/kvm_stat: handle guest removals more gracefully
        tools/kvm_stat: don't reset stats when setting PID filter for debugfs
        tools/kvm_stat: fix updates for dead guests
        tools/kvm_stat: fix handling of invalid paths in debugfs provider
        tools/kvm_stat: fix python3 issues
        KVM: x86: Unexport x86_emulate_instruction()
        KVM: x86: Rename emulate_instruction() to kvm_emulate_instruction()
        KVM: x86: Do not re-{try,execute} after failed emulation in L2
        KVM: x86: Default to not allowing emulation retry in kvm_mmu_page_fault
        ...
      f8f65382
    • Linus Torvalds's avatar
      Merge tag 'armsoc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc · 0f3aa48a
      Linus Torvalds authored
      Pull ARM SoC fixes from Olof Johansson:
       "A few more fixes who have trickled in:
      
         - MMC bus width fixup for some Allwinner platforms
      
         - Fix for NULL deref in ti-aemif when no platform data is passed in
      
         - Fix div by 0 in SCMI code
      
         - Add a missing module alias in a new RPi driver"
      
      * tag 'armsoc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc:
        memory: ti-aemif: fix a potential NULL-pointer dereference
        firmware: arm_scmi: fix divide by zero when sustained_perf_level is zero
        hwmon: rpi: add module alias to raspberrypi-hwmon
        arm64: allwinner: dts: h6: fix Pine H64 MMC bus width
      0f3aa48a
    • Olof Johansson's avatar
      Merge tag 'sunxi-fixes-for-4.19' of... · a132bb90
      Olof Johansson authored
      Merge tag 'sunxi-fixes-for-4.19' of https://git.kernel.org/pub/scm/linux/kernel/git/sunxi/linux into fixes
      
      Allwinner fixes for 4.19
      
      Just one fix for H6 mmc on the Pine H64: the mmc bus width was missing
      from the device tree. This was added in 4.19-rc1.
      
      * tag 'sunxi-fixes-for-4.19' of https://git.kernel.org/pub/scm/linux/kernel/git/sunxi/linux:
        arm64: allwinner: dts: h6: fix Pine H64 MMC bus width
      Signed-off-by: default avatarOlof Johansson <olof@lixom.net>
      a132bb90
    • Nadav Amit's avatar
      x86/mm: Use WRITE_ONCE() when setting PTEs · 9bc4f28a
      Nadav Amit authored
      When page-table entries are set, the compiler might optimize their
      assignment by using multiple instructions to set the PTE. This might
      turn into a security hazard if the user somehow manages to use the
      interim PTE. L1TF does not make our lives easier, making even an interim
      non-present PTE a security hazard.
      
      Using WRITE_ONCE() to set PTEs and friends should prevent this potential
      security hazard.
      
      I skimmed the differences in the binary with and without this patch. The
      differences are (obviously) greater when CONFIG_PARAVIRT=n as more
      code optimizations are possible. For better and worse, the impact on the
      binary with this patch is pretty small. Skimming the code did not cause
      anything to jump out as a security hazard, but it seems that at least
      move_soft_dirty_pte() caused set_pte_at() to use multiple writes.
      Signed-off-by: default avatarNadav Amit <namit@vmware.com>
      Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
      Acked-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
      Cc: Dave Hansen <dave.hansen@linux.intel.com>
      Cc: Andi Kleen <ak@linux.intel.com>
      Cc: Josh Poimboeuf <jpoimboe@redhat.com>
      Cc: Michal Hocko <mhocko@suse.com>
      Cc: Vlastimil Babka <vbabka@suse.cz>
      Cc: Sean Christopherson <sean.j.christopherson@intel.com>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: stable@vger.kernel.org
      Link: https://lkml.kernel.org/r/20180902181451.80520-1-namit@vmware.com
      9bc4f28a
    • Thomas Gleixner's avatar
      x86/apic/vector: Make error return value negative · 47b7360c
      Thomas Gleixner authored
      activate_managed() returns EINVAL instead of -EINVAL in case of
      error. While this is unlikely to happen, the positive return value would
      cause further malfunction at the call site.
      
      Fixes: 2db1f959 ("x86/vector: Handle managed interrupts proper")
      Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
      Cc: stable@vger.kernel.org
      47b7360c
    • Linus Torvalds's avatar
      Merge branch 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux · d7b686eb
      Linus Torvalds authored
      Pull i2c fixes from Wolfram Sang:
      
       - bugfixes for uniphier, i801, and xiic drivers
      
       - ID removal (never produced) for imx
      
       - one MAINTAINER addition
      
      * 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
        i2c: xiic: Record xilinx i2c with Zynq fragment
        i2c: xiic: Make the start and the byte count write atomic
        i2c: i801: fix DNV's SMBCTRL register offset
        i2c: imx-lpi2c: Remove mx8dv compatible entry
        dt-bindings: imx-lpi2c: Remove mx8dv compatible entry
        i2c: uniphier-f: issue STOP only for last message or I2C_M_STOP
        i2c: uniphier: issue STOP only for last message or I2C_M_STOP
      d7b686eb
  5. 07 Sep, 2018 21 commits
  6. 06 Sep, 2018 2 commits