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  1. 25 Jun, 2020 4 commits
    • Linus Torvalds's avatar
      Merge tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma · 87d93e9a
      Linus Torvalds authored 
      Pull rdma fixes from Jason Gunthorpe:
 "Several regression fixes from work that landed in the merge window,
  particularly in the mlx5 driver:

   - Various static checker and warning fixes

   - General bug fixes in rvt, qedr, hns, mlx5 and hfi1

   - Several regression fixes related to the ECE and QP changes in last
     cycle

   - Fixes for a few long standing crashers in CMA, uverbs ioctl, and
     xrc"

* tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma: (25 commits)
  IB/hfi1: Add atomic triggered sleep/wakeup
  IB/hfi1: Correct -EBUSY handling in tx code
  IB/hfi1: Fix module use count flaw due to leftover module put calls
  IB/hfi1: Restore kfree in dummy_netdev cleanup
  IB/mad: Fix use after free when destroying MAD agent
  RDMA/mlx5: Protect from kernel crash if XRC_TGT doesn't have udata
  RDMA/counter: Query a counter before release
  RDMA/mad: Fix possible memory leak in ib_mad_post_receive_mads()
  RDMA/mlx5: Fix integrity enabled QP creation
  RDMA/mlx5: Remove ECE limitation from the RAW_PACKET QPs
  RDMA/mlx5: Fix remote gid value in query QP
  RDMA/mlx5: Don't access ib_qp fields in internal destroy QP path
  RDMA/core: Check that type_attrs is not NULL prior access
  RDMA/hns: Fix an cmd queue issue when resetting
  RDMA/hns: Fix a calltrace when registering MR from userspace
  RDMA/mlx5: Add missed RST2INIT and INIT2INIT steps during ECE handshake
  RDMA/cma: Protect bind_list and listen_list while finding matching cm id
  RDMA/qedr: Fix KASAN: use-after-free in ucma_event_handler+0x532
  RDMA/efa: Set maximum pkeys device attribute
  RDMA/rvt: Fix potential memory leak caused by rvt_alloc_rq
  ...
      87d93e9a
    • Linus Torvalds's avatar
      Merge tag 's390-5.8-3' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux · 908f7d12
      Linus Torvalds authored 
      Pull s390 fixes from Heiko Carstens:

 - Fix kernel crash on system call single stepping.

 - Make sure early program check handler is executed with DAT on to
   avoid an endless program check loop.

 - Add __GFP_NOWARN flag to debug feature to avoid user triggerable
   allocation failure messages.

* tag 's390-5.8-3' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
  s390/debug: avoid kernel warning on too large number of pages
  s390/kasan: fix early pgm check handler execution
  s390: fix system call single stepping
      908f7d12
    • Linus Torvalds's avatar
      Merge tag 'sound-5.8-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound · a4d3712b
      Linus Torvalds authored 
      Pull sound fixes from Takashi Iwai:
 "A collection of small fixes gathered in the last two weeks.

  The major changes here are fixes for the recent DPCM regressions found
  on i.MX and Qualcomm platforms and fixes for resource leaks in ASoC
  DAI registrations.

  Other than those are mostly device-specific fixes including the usual
  USB- and HD-audio quirks, and a fix for syzkaller case and ID updates
  for new Intel platforms"

* tag 'sound-5.8-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound: (32 commits)
  ALSA: usb-audio: Fix OOB access of mixer element list
  ALSA: usb-audio: add quirk for Samsung USBC Headset (AKG)
  ALSA: usb-audio: Add registration quirk for Kingston HyperX Cloud Flight S
  ASoC: rockchip: Fix a reference count leak.
  ASoC: amd: closing specific instance.
  ALSA: hda: Intel: add missing PCI IDs for ICL-H, TGL-H and EKL
  ASoC: hdac_hda: fix memleak with regmap not freed on remove
  ASoC: SOF: Intel: add PCI IDs for ICL-H and TGL-H
  ASoC: SOF: Intel: add PCI ID for CometLake-S
  ASoC: Intel: SOF: merge COMETLAKE_LP and COMETLAKE_H
  ALSA: hda/realtek: Add mute LED and micmute LED support for HP systems
  ALSA: usb-audio: Fix potential use-after-free of streams
  ALSA: hda/realtek - Add quirk for MSI GE63 laptop
  ASoC: fsl_ssi: Fix bclk calculation for mono channel
  ASoC: SOF: Intel: hda: Clear RIRB status before reading WP
  ASoC: rt1015: Update rt1015 default register value according to spec modification.
  ASoC: qcom: common: set correct directions for dailinks
  ASoc: q6afe: add support to get port direction
  ASoC: soc-pcm: fix checks for multi-cpu FE dailinks
  ASoC: rt5682: Let dai clks be registered whether mclk exists or not
  ...
      a4d3712b
    • Linus Torvalds's avatar
      Merge tag 'erofs-for-5.8-rc3-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs · 8be3a53e
      Linus Torvalds authored 
      Pull erofs fix from Gao Xiang:
 "Fix a regression which uses potential uninitialized high 32-bit value
  unexpectedly recently observed with specific compiler options"

* tag 'erofs-for-5.8-rc3-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs:
  erofs: fix partially uninitialized misuse in z_erofs_onlinepage_fixup
      8be3a53e
  3. 24 Jun, 2020 8 commits
    • Linus Torvalds's avatar
      Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost · fc10807d
      Linus Torvalds authored 
      Pull virtio fixes from Michael Tsirkin:
 "Fixes all over the place.

  This includes a couple of tests that I would normally defer, but since
  they have already been helpful in catching some bugs, don't build for
  any users at all, and having them upstream makes life easier for
  everyone, I think it's ok even at this late stage"

* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
  tools/virtio: Use tools/include/list.h instead of stubs
  tools/virtio: Reset index in virtio_test --reset.
  tools/virtio: Extract virtqueue initialization in vq_reset
  tools/virtio: Use __vring_new_virtqueue in virtio_test.c
  tools/virtio: Add --reset
  tools/virtio: Add --batch=random option
  tools/virtio: Add --batch option
  virtio-mem: add memory via add_memory_driver_managed()
  virtio-mem: silence a static checker warning
  vhost_vdpa: Fix potential underflow in vhost_vdpa_mmap()
  vdpa: fix typos in the comments for __vdpa_alloc_device()
      fc10807d
    • Linus Torvalds's avatar
      Merge tag 'for-linus-2020-06-24' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux · fbb58011
      Linus Torvalds authored 
      Pull thread fix from Christian Brauner:
 "This fixes a regression introduced with 303cc571 ("nsproxy: attach
  to namespaces via pidfds").

  The LTP testsuite reported a regression where users would now see
  EBADF returned instead of EINVAL when an fd was passed that referred
  to an open file but the file was not a namespace file.

  Fix this by continuing to report EINVAL and add a regression test"

* tag 'for-linus-2020-06-24' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux:
  tests: test for setns() EINVAL regression
  nsproxy: restore EINVAL for non-namespace file descriptor
      fbb58011
    • Mike Marciniszyn's avatar
      IB/hfi1: Add atomic triggered sleep/wakeup · 38fd98af
      Mike Marciniszyn authored 
      When running iperf in a two host configuration the following trace can
occur:

[  319.728730] NETDEV WATCHDOG: ib0 (hfi1): transmit queue 0 timed out

The issue happens because the current implementation relies on the netif
txq being stopped to control the flushing of the tx list.

There are two resources that the transmit logic can wait on and stop the
txq:
- SDMA descriptors
- Ring space to hold completions

The ring space is tested on the sending side and relieved when the ring is
consumed in the napi tx reaping.

Unfortunately, that reaping can run conncurrently with the workqueue
flushing of the txlist.  If the txq is started just before the workitem
executes, the txlist will never be flushed, leading to the txq being
stuck.

Fix by:
- Adding sleep/wakeup wrappers
  * Use an atomic to control the call to the netif routines inside the
    wrappers

- Use another atomic to record ring space exhaustion
  * Only wakeup when the a ring space exhaustion has happened and it
    relieved

Add additional wrappers to clarify the ring space resource handling.

Fixes: d99dc602 ("IB/hfi1: Add functions to transmit datagram ipoib packets")
Link: https://lore.kernel.org/r/20200623204327.108092.4024.stgit@awfm-01.aw.intel.comReviewed-by: default avatarKaike Wan <kaike.wan@intel.com>
Signed-off-by: default avatarMike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: default avatarDennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: default avatarJason Gunthorpe <jgg@nvidia.com>
      38fd98af
    • Mike Marciniszyn's avatar
      IB/hfi1: Correct -EBUSY handling in tx code · 82172b76
      Mike Marciniszyn authored 
      The current code mishandles -EBUSY in two ways:
- The flow change doesn't test the return from the flush and runs on to
  process the current packet racing with the wakeup processing
- The -EBUSY handling for a single packet inserts the tx into the txlist
  after the submit call, racing with the same wakeup processing

Fix the first by dropping the skb and returning NETDEV_TX_OK.

Fix the second by insuring the the list entry within the txreq is inited
when allocated.  This enables the sleep routine to detect that the txreq
has used the non-list api and queue the packet to the txlist.

Both flaws can lead to having the flushing thread executing in causing two
threads to manipulate the txlist.

Fixes: d99dc602 ("IB/hfi1: Add functions to transmit datagram ipoib packets")
Link: https://lore.kernel.org/r/20200623204321.108092.83898.stgit@awfm-01.aw.intel.comReviewed-by: default avatarKaike Wan <kaike.wan@intel.com>
Signed-off-by: default avatarMike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: default avatarDennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: default avatarJason Gunthorpe <jgg@nvidia.com>
      82172b76
    • Dennis Dalessandro's avatar
      IB/hfi1: Fix module use count flaw due to leftover module put calls · 822fbd37
      Dennis Dalessandro authored 
      When the try_module_get calls were removed from opening and closing of the
i2c debugfs file, the corresponding module_put calls were missed.  This
results in an inaccurate module use count that requires a power cycle to
fix.

Fixes: 09fbca8e ("IB/hfi1: No need to use try_module_get for debugfs")
Link: https://lore.kernel.org/r/20200623203230.106975.76240.stgit@awfm-01.aw.intel.com
Cc: <stable@vger.kernel.org>
Reviewed-by: default avatarKaike Wan <kaike.wan@intel.com>
Reviewed-by: default avatarMike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: default avatarDennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: default avatarJason Gunthorpe <jgg@nvidia.com>
      822fbd37
    • Dennis Dalessandro's avatar
      IB/hfi1: Restore kfree in dummy_netdev cleanup · b46925a2
      Dennis Dalessandro authored 
      We need to do some rework on the dummy netdev. Calling the free_netdev()
would normally make sense, and that will be addressed in an upcoming
patch. For now just revert the behavior to what it was before keeping the
unused variable removal part of the patch.

The dd->dumm_netdev is mainly used for packet receiving through
alloc_netdev_mqs() for typical net devices. A a result, it should be freed
with kfree instead of free_netdev() that leads to a crash when unloading
the hfi1 module:

  BUG: kernel NULL pointer dereference, address: 0000000000000000
  #PF: supervisor read access in kernel mode
  #PF: error_code(0x0000) - not-present page
  PGD 8000000855b54067 P4D 8000000855b54067 PUD 84a4f5067 PMD 0
  Oops: 0000 [#1] SMP PTI
  CPU: 73 PID: 10299 Comm: modprobe Not tainted 5.6.0-rc5+ #1
  Hardware name: Intel Corporation S2600WT2R/S2600WT2R, BIOS SE5C610.86B.01.01.0016.033120161139 03/31/2016
  RIP: 0010:__hw_addr_flush+0x12/0x80
  Code: 40 00 48 83 c4 08 4c 89 e7 5b 5d 41 5c e9 76 77 18 00 66 0f 1f 44 00 00 0f 1f 44 00 00 41 54 49 89 fc 55 53 48 8b 1f 48 39 df <48> 8b 2b 75 08 eb 4a 48 89 eb 48 89 c5 48 89 df e8 99 bf d0 ff 84
  RSP: 0018:ffffb40e08783db8 EFLAGS: 00010282
  RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000002
  RDX: ffffb40e00000000 RSI: 0000000000000246 RDI: ffff88ab13662298
  RBP: ffff88ab13662000 R08: 0000000000001549 R09: 0000000000001549
  R10: 0000000000000001 R11: 0000000000aaaaaa R12: ffff88ab13662298
  R13: ffff88ab1b259e20 R14: ffff88ab1b259e42 R15: 0000000000000000
  FS:  00007fb39b534740(0000) GS:ffff88b31f940000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 0000000000000000 CR3: 000000084d3ea004 CR4: 00000000003606e0
  DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
  Call Trace:
   dev_addr_flush+0x15/0x30
   free_netdev+0x7e/0x130
   hfi1_netdev_free+0x59/0x70 [hfi1]
   remove_one+0x65/0x110 [hfi1]
   pci_device_remove+0x3b/0xc0
   device_release_driver_internal+0xec/0x1b0
   driver_detach+0x46/0x90
   bus_remove_driver+0x58/0xd0
   pci_unregister_driver+0x26/0xa0
   hfi1_mod_cleanup+0xc/0xd54 [hfi1]
   __x64_sys_delete_module+0x16c/0x260
   ? exit_to_usermode_loop+0xa4/0xc0
   do_syscall_64+0x5b/0x200
   entry_SYSCALL_64_after_hwframe+0x44/0xa9

Fixes: 193ba031 ("IB/hfi1: Use free_netdev() in hfi1_netdev_free()")
Link: https://lore.kernel.org/r/20200623203224.106975.16926.stgit@awfm-01.aw.intel.comReviewed-by: default avatarMike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: default avatarKaike Wan <kaike.wan@intel.com>
Signed-off-by: default avatarDennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: default avatarJason Gunthorpe <jgg@nvidia.com>
      b46925a2
    • Takashi Iwai's avatar
      ALSA: usb-audio: Fix OOB access of mixer element list · 220345e9
      Takashi Iwai authored 
      The USB-audio mixer code holds a linked list of usb_mixer_elem_list,
and several operations are performed for each mixer element.  A few of
them (snd_usb_mixer_notify_id() and snd_usb_mixer_interrupt_v2())
assume each mixer element being a usb_mixer_elem_info object that is a
subclass of usb_mixer_elem_list, cast via container_of() and access it
members.  This may result in an out-of-bound access when a
non-standard list element has been added, as spotted by syzkaller
recently.

This patch adds a new field, is_std_info, in usb_mixer_elem_list to
indicate that the element is the usb_mixer_elem_info type or not, and
skip the access to such an element if needed.

Reported-by: syzbot+fb14314433463ad51625@syzkaller.appspotmail.com
Reported-by: syzbot+2405ca3401e943c538b5@syzkaller.appspotmail.com
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20200624122340.9615-1-tiwai@suse.deSigned-off-by: default avatarTakashi Iwai <tiwai@suse.de>
      220345e9
    • Gao Xiang's avatar
      erofs: fix partially uninitialized misuse in z_erofs_onlinepage_fixup · 3c597282
      Gao Xiang authored 
      Hongyu reported "id != index" in z_erofs_onlinepage_fixup() with
specific aarch64 environment easily, which wasn't shown before.

After digging into that, I found that high 32 bits of page->private
was set to 0xaaaaaaaa rather than 0 (due to z_erofs_onlinepage_init
behavior with specific compiler options). Actually we only use low
32 bits to keep the page information since page->private is only 4
bytes on most 32-bit platforms. However z_erofs_onlinepage_fixup()
uses the upper 32 bits by mistake.

Let's fix it now.
Reported-and-tested-by: default avatarHongyu Jin <hongyu.jin@unisoc.com>
Fixes: 3883a79a ("staging: erofs: introduce VLE decompression support")
Cc: <stable@vger.kernel.org> # 4.19+
Reviewed-by: default avatarChao Yu <yuchao0@huawei.com>
Link: https://lore.kernel.org/r/20200618234349.22553-1-hsiangkao@aol.comSigned-off-by: default avatarGao Xiang <hsiangkao@redhat.com>
      3c597282
  5. 23 Jun, 2020 11 commits
    • Linus Torvalds's avatar
      Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm · 26e122e9
      Linus Torvalds authored 
      Pull kvm fixes from Paolo Bonzini:
 "All bugfixes except for a couple cleanup patches"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: VMX: Remove vcpu_vmx's defunct copy of host_pkru
  KVM: x86: allow TSC to differ by NTP correction bounds without TSC scaling
  KVM: X86: Fix MSR range of APIC registers in X2APIC mode
  KVM: VMX: Stop context switching MSR_IA32_UMWAIT_CONTROL
  KVM: nVMX: Plumb L2 GPA through to PML emulation
  KVM: x86/mmu: Avoid mixing gpa_t with gfn_t in walk_addr_generic()
  KVM: LAPIC: ensure APIC map is up to date on concurrent update requests
  kvm: lapic: fix broken vcpu hotplug
  Revert "KVM: VMX: Micro-optimize vmexit time when not exposing PMU"
  KVM: VMX: Add helpers to identify interrupt type from intr_info
  kvm/svm: disable KCSAN for svm_vcpu_run()
  KVM: MIPS: Fix a build error for !CPU_LOONGSON64
      26e122e9
    • Linus Torvalds's avatar
      Merge tag 'for-5.8-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux · 3e08a952
      Linus Torvalds authored 
      Pull btrfs fixes from David Sterba:
 "A number of fixes, located in two areas, one performance fix and one
  fixup for better integration with another patchset.

   - bug fixes in nowait aio:
       - fix snapshot creation hang after nowait-aio was used
       - fix failure to write to prealloc extent past EOF
       - don't block when extent range is locked

   - block group fixes:
       - relocation failure when scrub runs in parallel
       - refcount fix when removing fails
       - fix race between removal and creation
       - space accounting fixes

   - reinstante fast path check for log tree at unlink time, fixes
     performance drop up to 30% in REAIM

   - kzfree/kfree fixup to ease treewide patchset renaming kzfree"

* tag 'for-5.8-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: use kfree() in btrfs_ioctl_get_subvol_info()
  btrfs: fix RWF_NOWAIT writes blocking on extent locks and waiting for IO
  btrfs: fix RWF_NOWAIT write not failling when we need to cow
  btrfs: fix failure of RWF_NOWAIT write into prealloc extent beyond eof
  btrfs: fix hang on snapshot creation after RWF_NOWAIT write
  btrfs: check if a log root exists before locking the log_mutex on unlink
  btrfs: fix bytes_may_use underflow when running balance and scrub in parallel
  btrfs: fix data block group relocation failure due to concurrent scrub
  btrfs: fix race between block group removal and block group creation
  btrfs: fix a block group ref counter leak after failure to remove block group
      3e08a952
    • Macpaul Lin's avatar
      ALSA: usb-audio: add quirk for Samsung USBC Headset (AKG) · a32a1fc9
      Macpaul Lin authored 
      We've found Samsung USBC Headset (AKG) (VID: 0x04e8, PID: 0xa051)
need a tiny delay after each class compliant request.
Otherwise the device might not be able to be recognized each times.
Signed-off-by: default avatarChihhao Chen <chihhao.chen@mediatek.com>
Signed-off-by: default avatarMacpaul Lin <macpaul.lin@mediatek.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/1592910203-24035-1-git-send-email-macpaul.lin@mediatek.comSigned-off-by: default avatarTakashi Iwai <tiwai@suse.de>
      a32a1fc9
    • Christian Borntraeger's avatar
      s390/debug: avoid kernel warning on too large number of pages · 827c4913
      Christian Borntraeger authored 
      When specifying insanely large debug buffers a kernel warning is
printed. The debug code does handle the error gracefully, though.
Instead of duplicating the check let us silence the warning to
avoid crashes when panic_on_warn is used.
Signed-off-by: default avatarChristian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: default avatarHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: default avatarHeiko Carstens <heiko.carstens@de.ibm.com>
      827c4913
    • Vasily Gorbik's avatar
      s390/kasan: fix early pgm check handler execution · 998f5bbe
      Vasily Gorbik authored 
      Currently if early_pgm_check_handler is called it ends up in pgm check
loop. The problem is that early_pgm_check_handler is instrumented by
KASAN but executed without DAT flag enabled which leads to addressing
exception when KASAN checks try to access shadow memory.

Fix that by executing early handlers with DAT flag on under KASAN as
expected.
Reported-and-tested-by: default avatarAlexander Egorenkov <egorenar@linux.ibm.com>
Reviewed-by: default avatarHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: default avatarVasily Gorbik <gor@linux.ibm.com>
Signed-off-by: default avatarHeiko Carstens <heiko.carstens@de.ibm.com>
      998f5bbe
    • Sven Schnelle's avatar
      s390: fix system call single stepping · e64a1618
      Sven Schnelle authored 
      When single stepping an svc instruction on s390, the kernel is entered
with a PER program check interruption. The program check handler than
jumps to the system call handler by reloading the PSW. The code didn't
set GPR13 to the thread pointer in struct task_struct. This made the
kernel access invalid memory while trying to fetch the syscall function
address. Fix this by always assigned GPR13 after .Lsysc_per.

Fixes: 0b0ed657 ("s390: remove critical section cleanup from entry.S")
Reported-and-tested-by: default avatarChristian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: default avatarSven Schnelle <svens@linux.ibm.com>
Reviewed-by: default avatarHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: default avatarHeiko Carstens <heiko.carstens@de.ibm.com>
      e64a1618
    • Christoffer Nielsen's avatar
      ALSA: usb-audio: Add registration quirk for Kingston HyperX Cloud Flight S · 73094608
      Christoffer Nielsen authored 
      Similar to the Kingston HyperX AMP, the Kingston HyperX Cloud
Alpha S (0951:0x16ea) uses two interfaces, but only the second
interface contains the capture stream. This patch delays the
registration until the second interface appears.
Signed-off-by: default avatarChristoffer Nielsen <cn@obviux.dk>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/CAOtG2YHOM3zy+ed9KS-J4HkZo_QGzcUG9MigSp4e4_-13r6B=Q@mail.gmail.comSigned-off-by: default avatarTakashi Iwai <tiwai@suse.de>
      73094608
    • Sean Christopherson's avatar
      KVM: VMX: Remove vcpu_vmx's defunct copy of host_pkru · e4553b49
      Sean Christopherson authored 
      Remove vcpu_vmx.host_pkru, which got left behind when PKRU support was
moved to common x86 code.

No functional change intended.

Fixes: 37486135 ("KVM: x86: Fix pkru save/restore when guest CR4.PKE=0, move it to x86.c")
Signed-off-by: default avatarSean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200617034123.25647-1-sean.j.christopherson@intel.com>
Reviewed-by: default avatarVitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: default avatarJim Mattson <jmattson@google.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
      e4553b49
    • Marcelo Tosatti's avatar
      KVM: x86: allow TSC to differ by NTP correction bounds without TSC scaling · 26769f96
      Marcelo Tosatti authored 
      The Linux TSC calibration procedure is subject to small variations
(its common to see +-1 kHz difference between reboots on a given CPU, for example).

So migrating a guest between two hosts with identical processor can fail, in case
of a small variation in calibrated TSC between them.

Without TSC scaling, the current kernel interface will either return an error
(if user_tsc_khz <= tsc_khz) or enable TSC catchup mode.

This change enables the following TSC tolerance check to
accept KVM_SET_TSC_KHZ within tsc_tolerance_ppm (which is 250ppm by default).

        /*
         * Compute the variation in TSC rate which is acceptable
         * within the range of tolerance and decide if the
         * rate being applied is within that bounds of the hardware
         * rate.  If so, no scaling or compensation need be done.
         */
        thresh_lo = adjust_tsc_khz(tsc_khz, -tsc_tolerance_ppm);
        thresh_hi = adjust_tsc_khz(tsc_khz, tsc_tolerance_ppm);
        if (user_tsc_khz < thresh_lo || user_tsc_khz > thresh_hi) {
                pr_debug("kvm: requested TSC rate %u falls outside tolerance [%u,%u]\n", user_tsc_khz, thresh_lo, thresh_hi);
                use_scaling = 1;
        }

NTP daemon in the guest can correct this difference (NTP can correct upto 500ppm).
Signed-off-by: default avatarMarcelo Tosatti <mtosatti@redhat.com>

Message-Id: <20200616114741.GA298183@fuller.cnet>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
      26769f96
    • Xiaoyao Li's avatar
      KVM: X86: Fix MSR range of APIC registers in X2APIC mode · bf10bd0b
      Xiaoyao Li authored 
      Only MSR address range 0x800 through 0x8ff is architecturally reserved
and dedicated for accessing APIC registers in x2APIC mode.

Fixes: 0105d1a5 ("KVM: x2apic interface to lapic")
Signed-off-by: default avatarXiaoyao Li <xiaoyao.li@intel.com>
Message-Id: <20200616073307.16440-1-xiaoyao.li@intel.com>
Cc: stable@vger.kernel.org
Reviewed-by: default avatarSean Christopherson <sean.j.christopherson@intel.com>
Reviewed-by: default avatarJim Mattson <jmattson@google.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
      bf10bd0b
    • Sean Christopherson's avatar
      KVM: VMX: Stop context switching MSR_IA32_UMWAIT_CONTROL · bf09fb6c
      Sean Christopherson authored 
      Remove support for context switching between the guest's and host's
desired UMWAIT_CONTROL.  Propagating the guest's value to hardware isn't
required for correct functionality, e.g. KVM intercepts reads and writes
to the MSR, and the latency effects of the settings controlled by the
MSR are not architecturally visible.

As a general rule, KVM should not allow the guest to control power
management settings unless explicitly enabled by userspace, e.g. see
KVM_CAP_X86_DISABLE_EXITS.  E.g. Intel's SDM explicitly states that C0.2
can improve the performance of SMT siblings.  A devious guest could
disable C0.2 so as to improve the performance of their workloads at the
detriment to workloads running in the host or on other VMs.

Wholesale removal of UMWAIT_CONTROL context switching also fixes a race
condition where updates from the host may cause KVM to enter the guest
with the incorrect value.  Because updates are are propagated to all
CPUs via IPI (SMP function callback), the value in hardware may be
stale with respect to the cached value and KVM could enter the guest
with the wrong value in hardware.  As above, the guest can't observe the
bad value, but it's a weird and confusing wart in the implementation.

Removal also fixes the unnecessary usage of VMX's atomic load/store MSR
lists.  Using the lists is only necessary for MSRs that are required for
correct functionality immediately upon VM-Enter/VM-Exit, e.g. EFER on
old hardware, or for MSRs that need to-the-uop precision, e.g. perf
related MSRs.  For UMWAIT_CONTROL, the effects are only visible in the
kernel via TPAUSE/delay(), and KVM doesn't do any form of delay in
vcpu_vmx_run().  Using the atomic lists is undesirable as they are more
expensive than direct RDMSR/WRMSR.

Furthermore, even if giving the guest control of the MSR is legitimate,
e.g. in pass-through scenarios, it's not clear that the benefits would
outweigh the overhead.  E.g. saving and restoring an MSR across a VMX
roundtrip costs ~250 cycles, and if the guest diverged from the host
that cost would be paid on every run of the guest.  In other words, if
there is a legitimate use case then it should be enabled by a new
per-VM capability.

Note, KVM still needs to emulate MSR_IA32_UMWAIT_CONTROL so that it can
correctly expose other WAITPKG features to the guest, e.g. TPAUSE,
UMWAIT and UMONITOR.

Fixes: 6e3ba4ab ("KVM: vmx: Emulate MSR IA32_UMWAIT_CONTROL")
Cc: stable@vger.kernel.org
Cc: Jingqi Liu <jingqi.liu@intel.com>
Cc: Tao Xu <tao3.xu@intel.com>
Signed-off-by: default avatarSean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200623005135.10414-1-sean.j.christopherson@intel.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
      bf09fb6c
  7. 22 Jun, 2020 17 commits
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