linux.git/arch/x86/kernel, branch v4.18

x86/apic: Future-proof the TSC_DEADLINE quirk for SKX

2018-07-24T08:05:13+00:00

All SKX with stepping higher than 4 support the TSC_DEADLINE,
no matter the microcode version.

Without this patch, upcoming SKX steppings will not be able to use
their TSC_DEADLINE timer.

Signed-off-by: Len Brown 
Cc:  # v4.14+
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Fixes: 616dd5872e ("x86/apic: Update TSC_DEADLINE quirk with additional SKX stepping")
Link: http://lkml.kernel.org/r/d0c7129e509660be9ec6b233284b8d42d90659e8.1532207856.git.len.brown@intel.com
Signed-off-by: Ingo Molnar

Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2018-07-22T00:25:49+00:00

Pull x86 fix from Ingo Molnar:
 "A single fix for a MCE-polling regression, which prevented the
  disabling of polling"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/MCE: Remove min interval polling limitation

Merge branch 'x86-pti-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2018-07-22T00:23:58+00:00

Pull x86 pti fixes from Ingo Molnar:
 "An APM fix, and a BTS hardware-tracing fix related to PTI changes"

* 'x86-pti-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/apm: Don't access __preempt_count with zeroed fs
  x86/events/intel/ds: Fix bts_interrupt_threshold alignment

Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

2018-07-18T18:08:44+00:00

Pull kvm fixes from Paolo Bonzini:
 "Miscellaneous bugfixes, plus a small patchlet related to Spectre v2"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  kvmclock: fix TSC calibration for nested guests
  KVM: VMX: Mark VMXArea with revision_id of physical CPU even when eVMCS enabled
  KVM: irqfd: fix race between EPOLLHUP and irq_bypass_register_consumer
  KVM/Eventfd: Avoid crash when assign and deassign specific eventfd in parallel.
  x86/kvmclock: set pvti_cpu0_va after enabling kvmclock
  x86/kvm/Kconfig: Ensure CRYPTO_DEV_CCP_DD state at minimum matches KVM_AMD
  kvm: nVMX: Restore exit qual for VM-entry failure due to MSR loading
  x86/kvm/vmx: don't read current->thread.{fs,gs}base of legacy tasks
  KVM: VMX: support MSR_IA32_ARCH_CAPABILITIES as a feature MSR

kvmclock: fix TSC calibration for nested guests

2018-07-18T09:43:17+00:00

Inside a nested guest, access to hardware can be slow enough that
tsc_read_refs always return ULLONG_MAX, causing tsc_refine_calibration_work
to be called periodically and the nested guest to spend a lot of time
reading the ACPI timer.

However, if the TSC frequency is available from the pvclock page,
we can just set X86_FEATURE_TSC_KNOWN_FREQ and avoid the recalibration.
'refine' operation.

Suggested-by: Peter Zijlstra 
Signed-off-by: Peng Hao 
[Commit message rewritten. - Paolo]
Signed-off-by: Paolo Bonzini

x86/MCE: Remove min interval polling limitation

2018-07-17T15:56:25+00:00

commit b3b7c4795c ("x86/MCE: Serialize sysfs changes") introduced a min
interval limitation when setting the check interval for polled MCEs.
However, the logic is that 0 disables polling for corrected MCEs, see
Documentation/x86/x86_64/machinecheck. The limitation prevents disabling.

Remove this limitation and allow the value 0 to disable polling again.

Fixes: b3b7c4795c ("x86/MCE: Serialize sysfs changes")
Signed-off-by: Dewet Thibaut 
Signed-off-by: Alexander Sverdlin 
[ Massage commit message. ]
Signed-off-by: Borislav Petkov 
Signed-off-by: Thomas Gleixner 
Cc: Tony Luck 
Cc: linux-edac 
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/20180716084927.24869-1-alexander.sverdlin@nokia.com

x86/apm: Don't access __preempt_count with zeroed fs

2018-07-16T15:59:57+00:00

APM_DO_POP_SEGS does not restore fs/gs which were zeroed by
APM_DO_ZERO_SEGS. Trying to access __preempt_count with
zeroed fs doesn't really work.

Move the ibrs call outside the APM_DO_SAVE_SEGS/APM_DO_RESTORE_SEGS
invocations so that fs is actually restored before calling
preempt_enable().

Fixes the following sort of oopses:
[    0.313581] general protection fault: 0000 [#1] PREEMPT SMP
[    0.313803] Modules linked in:
[    0.314040] CPU: 0 PID: 268 Comm: kapmd Not tainted 4.16.0-rc1-triton-bisect-00090-gdd84441a7971 #19
[    0.316161] EIP: __apm_bios_call_simple+0xc8/0x170
[    0.316161] EFLAGS: 00210016 CPU: 0
[    0.316161] EAX: 00000102 EBX: 00000000 ECX: 00000102 EDX: 00000000
[    0.316161] ESI: 0000530e EDI: dea95f64 EBP: dea95f18 ESP: dea95ef0
[    0.316161]  DS: 007b ES: 007b FS: 0000 GS: 0000 SS: 0068
[    0.316161] CR0: 80050033 CR2: 00000000 CR3: 015d3000 CR4: 000006d0
[    0.316161] Call Trace:
[    0.316161]  ? cpumask_weight.constprop.15+0x20/0x20
[    0.316161]  on_cpu0+0x44/0x70
[    0.316161]  apm+0x54e/0x720
[    0.316161]  ? __switch_to_asm+0x26/0x40
[    0.316161]  ? __schedule+0x17d/0x590
[    0.316161]  kthread+0xc0/0xf0
[    0.316161]  ? proc_apm_show+0x150/0x150
[    0.316161]  ? kthread_create_worker_on_cpu+0x20/0x20
[    0.316161]  ret_from_fork+0x2e/0x38
[    0.316161] Code: da 8e c2 8e e2 8e ea 57 55 2e ff 1d e0 bb 5d b1 0f 92 c3 5d 5f 07 1f 89 47 0c 90 8d b4 26 00 00 00 00 90 8d b4 26 00 00 00 00 90 <64> ff 0d 84 16 5c b1 74 7f 8b 45 dc 8e e0 8b 45 d8 8e e8 8b 45
[    0.316161] EIP: __apm_bios_call_simple+0xc8/0x170 SS:ESP: 0068:dea95ef0
[    0.316161] ---[ end trace 656253db2deaa12c ]---

Fixes: dd84441a7971 ("x86/speculation: Use IBRS if available before calling into firmware")
Signed-off-by: Ville Syrjälä 
Signed-off-by: Thomas Gleixner 
Cc: stable@vger.kernel.org
Cc:  David Woodhouse 
Cc:  "H. Peter Anvin" 
Cc:  x86@kernel.org
Cc: David Woodhouse 
Cc: "H. Peter Anvin" 
Link: https://lkml.kernel.org/r/20180709133534.5963-1-ville.syrjala@linux.intel.com

x86/kvmclock: set pvti_cpu0_va after enabling kvmclock

2018-07-15T15:44:16+00:00

pvti_cpu0_va is the address of shared kvmclock data structure.

pvti_cpu0_va is currently kept unset (1) on 32 bit systems, (2) when
kvmclock vsyscall is disabled, and (3) if kvmclock is not stable.
This poses a problem, because kvm_ptp needs pvti_cpu0_va, but (1) can
work on 32 bit, (2) has little relation to the vsyscall, and (3) does
not need stable kvmclock (although kvmclock won't be used for system
clock if it's not stable, so kvm_ptp is pointless in that case).

Expose pvti_cpu0_va whenever kvmclock is enabled to allow all users to
work with it.

This fixes a regression found on Gentoo: https://bugs.gentoo.org/658544.

Fixes: 9f08890ab906 ("x86/pvclock: add setter for pvclock_pvti_cpu0_va")
Cc: stable@vger.kernel.org
Reported-by: Andreas Steinmetz 
Signed-off-by: Radim Krčmář 
Signed-off-by: Paolo Bonzini

Merge branch 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2018-07-08T20:56:25+00:00

Pull x86/pti updates from Thomas Gleixner:
 "Two small fixes correcting the handling of SSB mitigations on AMD
  processors"

* 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/bugs: Fix the AMD SSBD usage of the SPEC_CTRL MSR
  x86/bugs: Update when to check for the LS_CFG SSBD mitigation

x86/mtrr: Don't copy out-of-bounds data in mtrr_write

2018-07-07T16:58:41+00:00

Don't access the provided buffer out of bounds - this can cause a kernel
out-of-bounds read when invoked through sys_splice() or other things that
use kernel_write()/__kernel_write().

Fixes: 7f8ec5a4f01a ("x86/mtrr: Convert to use strncpy_from_user() helper")
Signed-off-by: Jann Horn 
Signed-off-by: Thomas Gleixner 
Cc: Andy Shevchenko 
Cc: "H. Peter Anvin" 
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20180706215003.156702-1-jannh@google.com