linux-stable.git/arch/x86/kernel/kvm.c, branch linux-4.7.y

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

2016-05-16T22:54:01+00:00

Pull x86 boot updates from Ingo Molnar:
 "The biggest changes in this cycle were:

   - prepare for more KASLR related changes, by restructuring, cleaning
     up and fixing the existing boot code.  (Kees Cook, Baoquan He,
     Yinghai Lu)

   - simplifly/concentrate subarch handling code, eliminate
     paravirt_enabled() usage.  (Luis R Rodriguez)"

* 'x86-boot-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (50 commits)
  x86/KASLR: Clarify purpose of each get_random_long()
  x86/KASLR: Add virtual address choosing function
  x86/KASLR: Return earliest overlap when avoiding regions
  x86/KASLR: Add 'struct slot_area' to manage random_addr slots
  x86/boot: Add missing file header comments
  x86/KASLR: Initialize mapping_info every time
  x86/boot: Comment what finalize_identity_maps() does
  x86/KASLR: Build identity mappings on demand
  x86/boot: Split out kernel_ident_mapping_init()
  x86/boot: Clean up indenting for asm/boot.h
  x86/KASLR: Improve comments around the mem_avoid[] logic
  x86/boot: Simplify pointer casting in choose_random_location()
  x86/KASLR: Consolidate mem_avoid[] entries
  x86/boot: Clean up pointer casting
  x86/boot: Warn on future overlapping memcpy() use
  x86/boot: Extract error reporting functions
  x86/boot: Correctly bounds-check relocations
  x86/KASLR: Clean up unused code from old 'run_size' and rename it to 'kernel_total_size'
  x86/boot: Fix "run_size" calculation
  x86/boot: Calculate decompression size during boot not build
  ...

x86/paravirt: Remove paravirt_enabled()

2016-04-22T08:29:07+00:00

Now that all previous paravirt_enabled() uses were replaced with proper
x86 semantics by the previous patches we can remove the unused
paravirt_enabled() mechanism.

Signed-off-by: Luis R. Rodriguez 
Acked-by: Juergen Gross 
Cc: Andy Lutomirski 
Cc: Borislav Petkov 
Cc: Brian Gerst 
Cc: Denys Vlasenko 
Cc: H. Peter Anvin 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: andrew.cooper3@citrix.com
Cc: andriy.shevchenko@linux.intel.com
Cc: bigeasy@linutronix.de
Cc: boris.ostrovsky@oracle.com
Cc: david.vrabel@citrix.com
Cc: ffainelli@freebox.fr
Cc: george.dunlap@citrix.com
Cc: glin@suse.com
Cc: jlee@suse.com
Cc: josh@joshtriplett.org
Cc: julien.grall@linaro.org
Cc: konrad.wilk@oracle.com
Cc: kozerkov@parallels.com
Cc: lenb@kernel.org
Cc: lguest@lists.ozlabs.org
Cc: linux-acpi@vger.kernel.org
Cc: lv.zheng@intel.com
Cc: matt@codeblueprint.co.uk
Cc: mbizon@freebox.fr
Cc: rjw@rjwysocki.net
Cc: robert.moore@intel.com
Cc: rusty@rustcorp.com.au
Cc: tiwai@suse.de
Cc: toshi.kani@hp.com
Cc: xen-devel@lists.xensource.com
Link: http://lkml.kernel.org/r/1460592286-300-15-git-send-email-mcgrof@kernel.org
Signed-off-by: Ingo Molnar

x86/cpufeature: Remove cpu_has_hypervisor

2016-03-31T11:35:07+00:00

Use boot_cpu_has() instead.

Tested-by: David Kershner 
Signed-off-by: Borislav Petkov 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: sparmaintainer@unisys.com
Cc: virtualization@lists.linux-foundation.org
Link: http://lkml.kernel.org/r/1459266123-21878-3-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar

kvm, rt: change async pagefault code locking for PREEMPT_RT

2016-03-22T15:38:38+00:00

The async pagefault wake code can run from the idle task in exception
context, so everything here needs to be made non-preemptible.

Conversion to a simple wait queue and raw spinlock does the trick.

Signed-off-by: Rik van Riel 
Signed-off-by: Paolo Bonzini

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

2015-06-24T16:36:49+00:00

Pull first batch of KVM updates from Paolo Bonzini:
 "The bulk of the changes here is for x86.  And for once it's not for
  silicon that no one owns: these are really new features for everyone.

  Details:

   - ARM:
        several features are in progress but missed the 4.2 deadline.
        So here is just a smattering of bug fixes, plus enabling the
        VFIO integration.

   - s390:
        Some fixes/refactorings/optimizations, plus support for 2GB
        pages.

   - x86:
        * host and guest support for marking kvmclock as a stable
          scheduler clock.
        * support for write combining.
        * support for system management mode, needed for secure boot in
          guests.
        * a bunch of cleanups required for the above
        * support for virtualized performance counters on AMD
        * legacy PCI device assignment is deprecated and defaults to "n"
          in Kconfig; VFIO replaces it

        On top of this there are also bug fixes and eager FPU context
        loading for FPU-heavy guests.

   - Common code:
        Support for multiple address spaces; for now it is used only for
        x86 SMM but the s390 folks also have plans"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (124 commits)
  KVM: s390: clear floating interrupt bitmap and parameters
  KVM: x86/vPMU: Enable PMU handling for AMD PERFCTRn and EVNTSELn MSRs
  KVM: x86/vPMU: Implement AMD vPMU code for KVM
  KVM: x86/vPMU: Define kvm_pmu_ops to support vPMU function dispatch
  KVM: x86/vPMU: introduce kvm_pmu_msr_idx_to_pmc
  KVM: x86/vPMU: reorder PMU functions
  KVM: x86/vPMU: whitespace and stylistic adjustments in PMU code
  KVM: x86/vPMU: use the new macros to go between PMC, PMU and VCPU
  KVM: x86/vPMU: introduce pmu.h header
  KVM: x86/vPMU: rename a few PMU functions
  KVM: MTRR: do not map huge page for non-consistent range
  KVM: MTRR: simplify kvm_mtrr_get_guest_memory_type
  KVM: MTRR: introduce mtrr_for_each_mem_type
  KVM: MTRR: introduce fixed_mtrr_addr_* functions
  KVM: MTRR: sort variable MTRRs
  KVM: MTRR: introduce var_mtrr_range
  KVM: MTRR: introduce fixed_mtrr_segment table
  KVM: MTRR: improve kvm_mtrr_get_guest_memory_type
  KVM: MTRR: do not split 64 bits MSR content
  KVM: MTRR: clean up mtrr default type
  ...

kvm: x86: Make functions that have no external callers static

2015-05-20T09:48:21+00:00

This makes the functions kvm_guest_cpu_init and  kvm_init_debugfs
static now due to having no external callers outside their
declarations in the file, kvm.c.

Signed-off-by: Nicholas Krause 
Signed-off-by: Paolo Bonzini

locking/pvqspinlock: Rename QUEUED_SPINLOCK to QUEUED_SPINLOCKS

2015-05-11T07:52:09+00:00

Valentin Rothberg reported that we use CONFIG_QUEUED_SPINLOCKS
in arch/x86/kernel/paravirt_patch_32.c, while the symbol is
called CONFIG_QUEUED_SPINLOCK. (Note the extra 'S')

But the typo was natural: the proper English term for such
a generic object would be 'queued spinlocks' - so rename
this and related symbols accordingly to the plural form.

Reported-by: Valentin Rothberg 
Cc: Douglas Hatch 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Scott J Norton 
Cc: Thomas Gleixner 
Cc: Waiman Long 
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar

locking/pvqspinlock, x86: Enable PV qspinlock for KVM

2015-05-08T10:37:17+00:00

This patch adds the necessary KVM specific code to allow KVM to
support the CPU halting and kicking operations needed by the queue
spinlock PV code.

Signed-off-by: Waiman Long 
Signed-off-by: Peter Zijlstra (Intel) 
Cc: Andrew Morton 
Cc: Boris Ostrovsky 
Cc: Borislav Petkov 
Cc: Daniel J Blueman 
Cc: David Vrabel 
Cc: Douglas Hatch 
Cc: H. Peter Anvin 
Cc: Konrad Rzeszutek Wilk 
Cc: Linus Torvalds 
Cc: Oleg Nesterov 
Cc: Paolo Bonzini 
Cc: Paul E. McKenney 
Cc: Peter Zijlstra 
Cc: Raghavendra K T 
Cc: Rik van Riel 
Cc: Scott J Norton 
Cc: Thomas Gleixner 
Cc: virtualization@lists.linux-foundation.org
Cc: xen-devel@lists.xenproject.org
Link: http://lkml.kernel.org/r/1429901803-29771-11-git-send-email-Waiman.Long@hp.com
Signed-off-by: Ingo Molnar

watchdog: introduce the hardlockup_detector_disable() function

2015-04-14T23:48:59+00:00

Have kvm_guest_init() use hardlockup_detector_disable() instead of
watchdog_enable_hardlockup_detector(false).

Remove the watchdog_hardlockup_detector_is_enabled() and the
watchdog_enable_hardlockup_detector() function which are no longer needed.

Signed-off-by: Ulrich Obergfell 
Signed-off-by: Don Zickus 
Cc: Ingo Molnar 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

x86/spinlocks/paravirt: Fix memory corruption on unlock

2015-02-18T13:53:49+00:00

Paravirt spinlock clears slowpath flag after doing unlock.
As explained by Linus currently it does:

                prev = *lock;
                add_smp(&lock->tickets.head, TICKET_LOCK_INC);

                /* add_smp() is a full mb() */

                if (unlikely(lock->tickets.tail & TICKET_SLOWPATH_FLAG))
                        __ticket_unlock_slowpath(lock, prev);

which is *exactly* the kind of things you cannot do with spinlocks,
because after you've done the "add_smp()" and released the spinlock
for the fast-path, you can't access the spinlock any more.  Exactly
because a fast-path lock might come in, and release the whole data
structure.

Linus suggested that we should not do any writes to lock after unlock(),
and we can move slowpath clearing to fastpath lock.

So this patch implements the fix with:

 1. Moving slowpath flag to head (Oleg):
    Unlocked locks don't care about the slowpath flag; therefore we can keep
    it set after the last unlock, and clear it again on the first (try)lock.
    -- this removes the write after unlock. note that keeping slowpath flag would
    result in unnecessary kicks.
    By moving the slowpath flag from the tail to the head ticket we also avoid
    the need to access both the head and tail tickets on unlock.

 2. use xadd to avoid read/write after unlock that checks the need for
    unlock_kick (Linus):
    We further avoid the need for a read-after-release by using xadd;
    the prev head value will include the slowpath flag and indicate if we
    need to do PV kicking of suspended spinners -- on modern chips xadd
    isn't (much) more expensive than an add + load.

Result:
 setup: 16core (32 cpu +ht sandy bridge 8GB 16vcpu guest)
 benchmark overcommit %improve
 kernbench  1x           -0.13
 kernbench  2x            0.02
 dbench     1x           -1.77
 dbench     2x           -0.63

[Jeremy: Hinted missing TICKET_LOCK_INC for kick]
[Oleg: Moved slowpath flag to head, ticket_equals idea]
[PeterZ: Added detailed changelog]

Suggested-by: Linus Torvalds 
Reported-by: Sasha Levin 
Tested-by: Sasha Levin 
Signed-off-by: Raghavendra K T 
Signed-off-by: Peter Zijlstra (Intel) 
Reviewed-by: Oleg Nesterov 
Cc: Andrew Jones 
Cc: Andrew Morton 
Cc: Andy Lutomirski 
Cc: Boris Ostrovsky 
Cc: Christian Borntraeger 
Cc: Christoph Lameter 
Cc: Dave Hansen 
Cc: Dave Jones 
Cc: David Vrabel 
Cc: Fernando Luis Vázquez Cao 
Cc: Konrad Rzeszutek Wilk 
Cc: Masami Hiramatsu 
Cc: Paolo Bonzini 
Cc: Paul E. McKenney 
Cc: Ulrich Obergfell 
Cc: Waiman Long 
Cc: a.ryabinin@samsung.com
Cc: dave@stgolabs.net
Cc: hpa@zytor.com
Cc: jasowang@redhat.com
Cc: jeremy@goop.org
Cc: paul.gortmaker@windriver.com
Cc: riel@redhat.com
Cc: tglx@linutronix.de
Cc: waiman.long@hp.com
Cc: xen-devel@lists.xenproject.org
Link: http://lkml.kernel.org/r/20150215173043.GA7471@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar