Commit Graph

699 Commits

Author SHA1 Message Date
Paolo Bonzini
8fe65a8299 kvm: rename last argument to kvm_get_dirty_log_protect
When manual dirty log reprotect will be enabled, kvm_get_dirty_log_protect's
pointer argument will always be false on exit, because no TLB flush is needed
until the manual re-protection operation.  Rename it from "is_dirty" to "flush",
which more accurately tells the caller what they have to do with it.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-12-14 12:34:18 +01:00
Paolo Bonzini
e5d83c74a5 kvm: make KVM_CAP_ENABLE_CAP_VM architecture agnostic
The first such capability to be handled in virt/kvm/ will be manual
dirty page reprotection.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-12-14 12:34:18 +01:00
Michal Hocko
4e15a073a1 Revert "mm, mmu_notifier: annotate mmu notifiers with blockable invalidate callbacks"
Revert 5ff7091f5a ("mm, mmu_notifier: annotate mmu notifiers with
blockable invalidate callbacks").

MMU_INVALIDATE_DOES_NOT_BLOCK flags was the only one used and it is no
longer needed since 93065ac753 ("mm, oom: distinguish blockable mode for
mmu notifiers").  We now have a full support for per range !blocking
behavior so we can drop the stop gap workaround which the per notifier
flag was used for.

Link: http://lkml.kernel.org/r/20180827112623.8992-4-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-10-26 16:25:19 -07:00
Wei Yang
970c0d4b94 KVM: refine the comment of function gfn_to_hva_memslot_prot()
The original comment is little hard to understand.

No functional change, just amend the comment a little.

Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-10-17 00:30:13 +02:00
Peng Hao
0804c849f1 kvm/x86 : add coalesced pio support
Coalesced pio is based on coalesced mmio and can be used for some port
like rtc port, pci-host config port and so on.

Specially in case of rtc as coalesced pio, some versions of windows guest
access rtc frequently because of rtc as system tick. guest access rtc like
this: write register index to 0x70, then write or read data from 0x71.
writing 0x70 port is just as index and do nothing else. So we can use
coalesced pio to handle this scene to reduce VM-EXIT time.

When starting and closing a virtual machine, it will access pci-host config
port frequently. So setting these port as coalesced pio can reduce startup
and shutdown time.

without my patch, get the vm-exit time of accessing rtc 0x70 and piix 0xcf8
using perf tools: (guest OS : windows 7 64bit)
IO Port Access  Samples Samples%  Time%  Min Time  Max Time  Avg time
0x70:POUT        86     30.99%    74.59%   9us      29us    10.75us (+- 3.41%)
0xcf8:POUT     1119     2.60%     2.12%   2.79us    56.83us 3.41us (+- 2.23%)

with my patch
IO Port Access  Samples Samples%  Time%   Min Time  Max Time   Avg time
0x70:POUT       106    32.02%    29.47%    0us      10us     1.57us (+- 7.38%)
0xcf8:POUT      1065    1.67%     0.28%   0.41us    65.44us   0.66us (+- 10.55%)

Signed-off-by: Peng Hao <peng.hao2@zte.com.cn>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-10-17 00:30:11 +02:00
Wei Yang
31fc4f95dd KVM: leverage change to adjust slots->used_slots in update_memslots()
update_memslots() is only called by __kvm_set_memory_region(), in which
"change" is calculated and indicates how to adjust slots->used_slots

  * increase by one if it is KVM_MR_CREATE
  * decrease by one if it is KVM_MR_DELETE
  * not change for others

This patch adjusts slots->used_slots in update_memslots() based on "change"
value instead of re-calculate those states again.

Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-10-17 00:29:48 +02:00
Vitaly Kuznetsov
a812297c4f KVM: x86: hyperv: optimize 'all cpus' case in kvm_hv_flush_tlb()
We can use 'NULL' to represent 'all cpus' case in
kvm_make_vcpus_request_mask() and avoid building vCPU mask with
all vCPUs.

Suggested-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Roman Kagan <rkagan@virtuozzo.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-10-17 00:29:44 +02:00
Linus Torvalds
cd9b44f907 Merge branch 'akpm' (patches from Andrew)
Merge more updates from Andrew Morton:

 - the rest of MM

 - procfs updates

 - various misc things

 - more y2038 fixes

 - get_maintainer updates

 - lib/ updates

 - checkpatch updates

 - various epoll updates

 - autofs updates

 - hfsplus

 - some reiserfs work

 - fatfs updates

 - signal.c cleanups

 - ipc/ updates

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (166 commits)
  ipc/util.c: update return value of ipc_getref from int to bool
  ipc/util.c: further variable name cleanups
  ipc: simplify ipc initialization
  ipc: get rid of ids->tables_initialized hack
  lib/rhashtable: guarantee initial hashtable allocation
  lib/rhashtable: simplify bucket_table_alloc()
  ipc: drop ipc_lock()
  ipc/util.c: correct comment in ipc_obtain_object_check
  ipc: rename ipcctl_pre_down_nolock()
  ipc/util.c: use ipc_rcu_putref() for failues in ipc_addid()
  ipc: reorganize initialization of kern_ipc_perm.seq
  ipc: compute kern_ipc_perm.id under the ipc lock
  init/Kconfig: remove EXPERT from CHECKPOINT_RESTORE
  fs/sysv/inode.c: use ktime_get_real_seconds() for superblock stamp
  adfs: use timespec64 for time conversion
  kernel/sysctl.c: fix typos in comments
  drivers/rapidio/devices/rio_mport_cdev.c: remove redundant pointer md
  fork: don't copy inconsistent signal handler state to child
  signal: make get_signal() return bool
  signal: make sigkill_pending() return bool
  ...
2018-08-22 12:34:08 -07:00
Michal Hocko
93065ac753 mm, oom: distinguish blockable mode for mmu notifiers
There are several blockable mmu notifiers which might sleep in
mmu_notifier_invalidate_range_start and that is a problem for the
oom_reaper because it needs to guarantee a forward progress so it cannot
depend on any sleepable locks.

Currently we simply back off and mark an oom victim with blockable mmu
notifiers as done after a short sleep.  That can result in selecting a new
oom victim prematurely because the previous one still hasn't torn its
memory down yet.

We can do much better though.  Even if mmu notifiers use sleepable locks
there is no reason to automatically assume those locks are held.  Moreover
majority of notifiers only care about a portion of the address space and
there is absolutely zero reason to fail when we are unmapping an unrelated
range.  Many notifiers do really block and wait for HW which is harder to
handle and we have to bail out though.

This patch handles the low hanging fruit.
__mmu_notifier_invalidate_range_start gets a blockable flag and callbacks
are not allowed to sleep if the flag is set to false.  This is achieved by
using trylock instead of the sleepable lock for most callbacks and
continue as long as we do not block down the call chain.

I think we can improve that even further because there is a common pattern
to do a range lookup first and then do something about that.  The first
part can be done without a sleeping lock in most cases AFAICS.

The oom_reaper end then simply retries if there is at least one notifier
which couldn't make any progress in !blockable mode.  A retry loop is
already implemented to wait for the mmap_sem and this is basically the
same thing.

The simplest way for driver developers to test this code path is to wrap
userspace code which uses these notifiers into a memcg and set the hard
limit to hit the oom.  This can be done e.g.  after the test faults in all
the mmu notifier managed memory and set the hard limit to something really
small.  Then we are looking for a proper process tear down.

[akpm@linux-foundation.org: coding style fixes]
[akpm@linux-foundation.org: minor code simplification]
Link: http://lkml.kernel.org/r/20180716115058.5559-1-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Acked-by: Christian König <christian.koenig@amd.com> # AMD notifiers
Acked-by: Leon Romanovsky <leonro@mellanox.com> # mlx and umem_odp
Reported-by: David Rientjes <rientjes@google.com>
Cc: "David (ChunMing) Zhou" <David1.Zhou@amd.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Doug Ledford <dledford@redhat.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Mike Marciniszyn <mike.marciniszyn@intel.com>
Cc: Dennis Dalessandro <dennis.dalessandro@intel.com>
Cc: Sudeep Dutt <sudeep.dutt@intel.com>
Cc: Ashutosh Dixit <ashutosh.dixit@intel.com>
Cc: Dimitri Sivanich <sivanich@sgi.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: "Jérôme Glisse" <jglisse@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Felix Kuehling <felix.kuehling@amd.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22 10:52:44 -07:00
Linus Torvalds
0214f46b3a Merge branch 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull core signal handling updates from Eric Biederman:
 "It was observed that a periodic timer in combination with a
  sufficiently expensive fork could prevent fork from every completing.
  This contains the changes to remove the need for that restart.

  This set of changes is split into several parts:

   - The first part makes PIDTYPE_TGID a proper pid type instead
     something only for very special cases. The part starts using
     PIDTYPE_TGID enough so that in __send_signal where signals are
     actually delivered we know if the signal is being sent to a a group
     of processes or just a single process.

   - With that prep work out of the way the logic in fork is modified so
     that fork logically makes signals received while it is running
     appear to be received after the fork completes"

* 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (22 commits)
  signal: Don't send signals to tasks that don't exist
  signal: Don't restart fork when signals come in.
  fork: Have new threads join on-going signal group stops
  fork: Skip setting TIF_SIGPENDING in ptrace_init_task
  signal: Add calculate_sigpending()
  fork: Unconditionally exit if a fatal signal is pending
  fork: Move and describe why the code examines PIDNS_ADDING
  signal: Push pid type down into complete_signal.
  signal: Push pid type down into __send_signal
  signal: Push pid type down into send_signal
  signal: Pass pid type into do_send_sig_info
  signal: Pass pid type into send_sigio_to_task & send_sigurg_to_task
  signal: Pass pid type into group_send_sig_info
  signal: Pass pid and pid type into send_sigqueue
  posix-timers: Noralize good_sigevent
  signal: Use PIDTYPE_TGID to clearly store where file signals will be sent
  pid: Implement PIDTYPE_TGID
  pids: Move the pgrp and session pid pointers from task_struct to signal_struct
  kvm: Don't open code task_pid in kvm_vcpu_ioctl
  pids: Compute task_tgid using signal->leader_pid
  ...
2018-08-21 13:47:29 -07:00
Linus Torvalds
e61cf2e3a5 Minor code cleanups for PPC.
For x86 this brings in PCID emulation and CR3 caching for shadow page
 tables, nested VMX live migration, nested VMCS shadowing, an optimized
 IPI hypercall, and some optimizations.
 
 ARM will come next week.
 
 There is a semantic conflict because tip also added an .init_platform
 callback to kvm.c.  Please keep the initializer from this branch,
 and add a call to kvmclock_init (added by tip) inside kvm_init_platform
 (added here).
 
 Also, there is a backmerge from 4.18-rc6.  This is because of a
 refactoring that conflicted with a relatively late bugfix and
 resulted in a particularly hellish conflict.  Because the conflict
 was only due to unfortunate timing of the bugfix, I backmerged and
 rebased the refactoring rather than force the resolution on you.
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull first set of KVM updates from Paolo Bonzini:
 "PPC:
   - minor code cleanups

  x86:
   - PCID emulation and CR3 caching for shadow page tables
   - nested VMX live migration
   - nested VMCS shadowing
   - optimized IPI hypercall
   - some optimizations

  ARM will come next week"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (85 commits)
  kvm: x86: Set highest physical address bits in non-present/reserved SPTEs
  KVM/x86: Use CC_SET()/CC_OUT in arch/x86/kvm/vmx.c
  KVM: X86: Implement PV IPIs in linux guest
  KVM: X86: Add kvm hypervisor init time platform setup callback
  KVM: X86: Implement "send IPI" hypercall
  KVM/x86: Move X86_CR4_OSXSAVE check into kvm_valid_sregs()
  KVM: x86: Skip pae_root shadow allocation if tdp enabled
  KVM/MMU: Combine flushing remote tlb in mmu_set_spte()
  KVM: vmx: skip VMWRITE of HOST_{FS,GS}_BASE when possible
  KVM: vmx: skip VMWRITE of HOST_{FS,GS}_SEL when possible
  KVM: vmx: always initialize HOST_{FS,GS}_BASE to zero during setup
  KVM: vmx: move struct host_state usage to struct loaded_vmcs
  KVM: vmx: compute need to reload FS/GS/LDT on demand
  KVM: nVMX: remove a misleading comment regarding vmcs02 fields
  KVM: vmx: rename __vmx_load_host_state() and vmx_save_host_state()
  KVM: vmx: add dedicated utility to access guest's kernel_gs_base
  KVM: vmx: track host_state.loaded using a loaded_vmcs pointer
  KVM: vmx: refactor segmentation code in vmx_save_host_state()
  kvm: nVMX: Fix fault priority for VMX operations
  kvm: nVMX: Fix fault vector for VMX operation at CPL > 0
  ...
2018-08-19 10:38:36 -07:00
Paolo Bonzini
b9b33da2aa KVM: try __get_user_pages_fast even if not in atomic context
We are currently cutting hva_to_pfn_fast short if we do not want an
immediate exit, which is represented by !async && !atomic.  However,
this is unnecessary, and __get_user_pages_fast is *much* faster
because the regular get_user_pages takes pmd_lock/pte_lock.
In fact, when many CPUs take a nested vmexit at the same time
the contention on those locks is visible, and this patch removes
about 25% (compared to 4.18) from vmexit.flat on a 16 vCPU
nested guest.

Suggested-by: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-08-06 17:59:07 +02:00
Tianyu Lan
b08660e59d KVM: x86: Add tlb remote flush callback in kvm_x86_ops.
This patch is to provide a way for platforms to register hv tlb remote
flush callback and this helps to optimize operation of tlb flush
among vcpus for nested virtualization case.

Signed-off-by: Lan Tianyu <Tianyu.Lan@microsoft.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-08-06 17:59:06 +02:00
Junaid Shahid
50c28f21d0 kvm: x86: Use fast CR3 switch for nested VMX
Use the fast CR3 switch mechanism to locklessly change the MMU root
page when switching between L1 and L2. The switch from L2 to L1 should
always go through the fast path, while the switch from L1 to L2 should
go through the fast path if L1's CR3/EPTP for L2 hasn't changed
since the last time.

Signed-off-by: Junaid Shahid <junaids@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-08-06 17:58:54 +02:00
Eric W. Biederman
71dbc8a969 kvm: Don't open code task_pid in kvm_vcpu_ioctl
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2018-07-21 10:43:12 -05:00
Claudio Imbrenda
03133347b4 KVM: s390: a utility function for migration
Introduce a utility function that will be used later on for storage
attributes migration, and use it in kvm_main.c to replace existing code
that does the same thing.

Signed-off-by: Claudio Imbrenda <imbrenda@linux.vnet.ibm.com>
Message-Id: <1525106005-13931-2-git-send-email-imbrenda@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2018-07-13 09:48:57 +02:00
Ingo Molnar
4520843dfa Merge branch 'sched/urgent' into sched/core, to pick up fixes
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-03 09:20:22 +02:00
Marc Zyngier
7ddfd3e0df KVM: Enforce error in ioctl for compat tasks when !KVM_COMPAT
The current behaviour of the compat ioctls is a bit odd.
We provide a compat_ioctl method when KVM_COMPAT is set, and NULL
otherwise. But NULL means that the normal, non-compat ioctl should
be used directly for compat tasks, and there is no way to actually
prevent a compat task from issueing KVM ioctls.

This patch changes this behaviour, by always registering a compat_ioctl
method, even if KVM_COMPAT is not selected. In that case, the callback
will always return -EINVAL.

Fixes: de8e5d7440 ("KVM: Disable compat ioctl for s390")
Reported-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-06-21 17:17:50 +01:00
Peter Zijlstra
b3dae109fa sched/swait: Rename to exclusive
Since swait basically implemented exclusive waits only, make sure
the API reflects that.

  $ git grep -l -e "\<swake_up\>"
		-e "\<swait_event[^ (]*"
		-e "\<prepare_to_swait\>" | while read file;
    do
	sed -i -e 's/\<swake_up\>/&_one/g'
	       -e 's/\<swait_event[^ (]*/&_exclusive/g'
	       -e 's/\<prepare_to_swait\>/&_exclusive/g' $file;
    done

With a few manual touch-ups.

Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: bigeasy@linutronix.de
Cc: oleg@redhat.com
Cc: paulmck@linux.vnet.ibm.com
Cc: pbonzini@redhat.com
Link: https://lkml.kernel.org/r/20180612083909.261946548@infradead.org
2018-06-20 11:35:56 +02:00
Linus Torvalds
b08fc5277a - Error path bug fix for overflow tests (Dan)
- Additional struct_size() conversions (Matthew, Kees)
 - Explicitly reported overflow fixes (Silvio, Kees)
 - Add missing kvcalloc() function (Kees)
 - Treewide conversions of allocators to use either 2-factor argument
   variant when available, or array_size() and array3_size() as needed (Kees)
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Merge tag 'overflow-v4.18-rc1-part2' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull more overflow updates from Kees Cook:
 "The rest of the overflow changes for v4.18-rc1.

  This includes the explicit overflow fixes from Silvio, further
  struct_size() conversions from Matthew, and a bug fix from Dan.

  But the bulk of it is the treewide conversions to use either the
  2-factor argument allocators (e.g. kmalloc(a * b, ...) into
  kmalloc_array(a, b, ...) or the array_size() macros (e.g. vmalloc(a *
  b) into vmalloc(array_size(a, b)).

  Coccinelle was fighting me on several fronts, so I've done a bunch of
  manual whitespace updates in the patches as well.

  Summary:

   - Error path bug fix for overflow tests (Dan)

   - Additional struct_size() conversions (Matthew, Kees)

   - Explicitly reported overflow fixes (Silvio, Kees)

   - Add missing kvcalloc() function (Kees)

   - Treewide conversions of allocators to use either 2-factor argument
     variant when available, or array_size() and array3_size() as needed
     (Kees)"

* tag 'overflow-v4.18-rc1-part2' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: (26 commits)
  treewide: Use array_size in f2fs_kvzalloc()
  treewide: Use array_size() in f2fs_kzalloc()
  treewide: Use array_size() in f2fs_kmalloc()
  treewide: Use array_size() in sock_kmalloc()
  treewide: Use array_size() in kvzalloc_node()
  treewide: Use array_size() in vzalloc_node()
  treewide: Use array_size() in vzalloc()
  treewide: Use array_size() in vmalloc()
  treewide: devm_kzalloc() -> devm_kcalloc()
  treewide: devm_kmalloc() -> devm_kmalloc_array()
  treewide: kvzalloc() -> kvcalloc()
  treewide: kvmalloc() -> kvmalloc_array()
  treewide: kzalloc_node() -> kcalloc_node()
  treewide: kzalloc() -> kcalloc()
  treewide: kmalloc() -> kmalloc_array()
  mm: Introduce kvcalloc()
  video: uvesafb: Fix integer overflow in allocation
  UBIFS: Fix potential integer overflow in allocation
  leds: Use struct_size() in allocation
  Convert intel uncore to struct_size
  ...
2018-06-12 18:28:00 -07:00
Kees Cook
42bc47b353 treewide: Use array_size() in vmalloc()
The vmalloc() function has no 2-factor argument form, so multiplication
factors need to be wrapped in array_size(). This patch replaces cases of:

        vmalloc(a * b)

with:
        vmalloc(array_size(a, b))

as well as handling cases of:

        vmalloc(a * b * c)

with:

        vmalloc(array3_size(a, b, c))

This does, however, attempt to ignore constant size factors like:

        vmalloc(4 * 1024)

though any constants defined via macros get caught up in the conversion.

Any factors with a sizeof() of "unsigned char", "char", and "u8" were
dropped, since they're redundant.

The Coccinelle script used for this was:

// Fix redundant parens around sizeof().
@@
type TYPE;
expression THING, E;
@@

(
  vmalloc(
-	(sizeof(TYPE)) * E
+	sizeof(TYPE) * E
  , ...)
|
  vmalloc(
-	(sizeof(THING)) * E
+	sizeof(THING) * E
  , ...)
)

// Drop single-byte sizes and redundant parens.
@@
expression COUNT;
typedef u8;
typedef __u8;
@@

(
  vmalloc(
-	sizeof(u8) * (COUNT)
+	COUNT
  , ...)
|
  vmalloc(
-	sizeof(__u8) * (COUNT)
+	COUNT
  , ...)
|
  vmalloc(
-	sizeof(char) * (COUNT)
+	COUNT
  , ...)
|
  vmalloc(
-	sizeof(unsigned char) * (COUNT)
+	COUNT
  , ...)
|
  vmalloc(
-	sizeof(u8) * COUNT
+	COUNT
  , ...)
|
  vmalloc(
-	sizeof(__u8) * COUNT
+	COUNT
  , ...)
|
  vmalloc(
-	sizeof(char) * COUNT
+	COUNT
  , ...)
|
  vmalloc(
-	sizeof(unsigned char) * COUNT
+	COUNT
  , ...)
)

// 2-factor product with sizeof(type/expression) and identifier or constant.
@@
type TYPE;
expression THING;
identifier COUNT_ID;
constant COUNT_CONST;
@@

(
  vmalloc(
-	sizeof(TYPE) * (COUNT_ID)
+	array_size(COUNT_ID, sizeof(TYPE))
  , ...)
|
  vmalloc(
-	sizeof(TYPE) * COUNT_ID
+	array_size(COUNT_ID, sizeof(TYPE))
  , ...)
|
  vmalloc(
-	sizeof(TYPE) * (COUNT_CONST)
+	array_size(COUNT_CONST, sizeof(TYPE))
  , ...)
|
  vmalloc(
-	sizeof(TYPE) * COUNT_CONST
+	array_size(COUNT_CONST, sizeof(TYPE))
  , ...)
|
  vmalloc(
-	sizeof(THING) * (COUNT_ID)
+	array_size(COUNT_ID, sizeof(THING))
  , ...)
|
  vmalloc(
-	sizeof(THING) * COUNT_ID
+	array_size(COUNT_ID, sizeof(THING))
  , ...)
|
  vmalloc(
-	sizeof(THING) * (COUNT_CONST)
+	array_size(COUNT_CONST, sizeof(THING))
  , ...)
|
  vmalloc(
-	sizeof(THING) * COUNT_CONST
+	array_size(COUNT_CONST, sizeof(THING))
  , ...)
)

// 2-factor product, only identifiers.
@@
identifier SIZE, COUNT;
@@

  vmalloc(
-	SIZE * COUNT
+	array_size(COUNT, SIZE)
  , ...)

// 3-factor product with 1 sizeof(type) or sizeof(expression), with
// redundant parens removed.
@@
expression THING;
identifier STRIDE, COUNT;
type TYPE;
@@

(
  vmalloc(
-	sizeof(TYPE) * (COUNT) * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  vmalloc(
-	sizeof(TYPE) * (COUNT) * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  vmalloc(
-	sizeof(TYPE) * COUNT * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  vmalloc(
-	sizeof(TYPE) * COUNT * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  vmalloc(
-	sizeof(THING) * (COUNT) * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
|
  vmalloc(
-	sizeof(THING) * (COUNT) * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
|
  vmalloc(
-	sizeof(THING) * COUNT * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
|
  vmalloc(
-	sizeof(THING) * COUNT * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
)

// 3-factor product with 2 sizeof(variable), with redundant parens removed.
@@
expression THING1, THING2;
identifier COUNT;
type TYPE1, TYPE2;
@@

(
  vmalloc(
-	sizeof(TYPE1) * sizeof(TYPE2) * COUNT
+	array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
  , ...)
|
  vmalloc(
-	sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+	array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
  , ...)
|
  vmalloc(
-	sizeof(THING1) * sizeof(THING2) * COUNT
+	array3_size(COUNT, sizeof(THING1), sizeof(THING2))
  , ...)
|
  vmalloc(
-	sizeof(THING1) * sizeof(THING2) * (COUNT)
+	array3_size(COUNT, sizeof(THING1), sizeof(THING2))
  , ...)
|
  vmalloc(
-	sizeof(TYPE1) * sizeof(THING2) * COUNT
+	array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
  , ...)
|
  vmalloc(
-	sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+	array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
  , ...)
)

// 3-factor product, only identifiers, with redundant parens removed.
@@
identifier STRIDE, SIZE, COUNT;
@@

(
  vmalloc(
-	(COUNT) * STRIDE * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  vmalloc(
-	COUNT * (STRIDE) * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  vmalloc(
-	COUNT * STRIDE * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  vmalloc(
-	(COUNT) * (STRIDE) * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  vmalloc(
-	COUNT * (STRIDE) * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  vmalloc(
-	(COUNT) * STRIDE * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  vmalloc(
-	(COUNT) * (STRIDE) * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  vmalloc(
-	COUNT * STRIDE * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
)

// Any remaining multi-factor products, first at least 3-factor products
// when they're not all constants...
@@
expression E1, E2, E3;
constant C1, C2, C3;
@@

(
  vmalloc(C1 * C2 * C3, ...)
|
  vmalloc(
-	E1 * E2 * E3
+	array3_size(E1, E2, E3)
  , ...)
)

// And then all remaining 2 factors products when they're not all constants.
@@
expression E1, E2;
constant C1, C2;
@@

(
  vmalloc(C1 * C2, ...)
|
  vmalloc(
-	E1 * E2
+	array_size(E1, E2)
  , ...)
)

Signed-off-by: Kees Cook <keescook@chromium.org>
2018-06-12 16:19:22 -07:00
Greg Kroah-Hartman
929f45e324 kvm: no need to check return value of debugfs_create functions
When calling debugfs functions, there is no need to ever check the
return value.  The function can work or not, but the code logic should
never do something different based on this.

This cleans up the error handling a lot, as this code will never get
hit.

Cc: Paul Mackerras <paulus@ozlabs.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Christoffer Dall <christoffer.dall@arm.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Radim KrÄmář" <rkrcmar@redhat.com>
Cc: Arvind Yadav <arvind.yadav.cs@gmail.com>
Cc: Eric Auger <eric.auger@redhat.com>
Cc: Andre Przywara <andre.przywara@arm.com>
Cc: kvm-ppc@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: kvmarm@lists.cs.columbia.edu
Cc: kvm@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-06-01 19:18:27 +02:00
Souptick Joarder
1499fa809e kvm: Change return type to vm_fault_t
Use new return type vm_fault_t for fault handler. For
now, this is just documenting that the function returns
a VM_FAULT value rather than an errno. Once all instances
are converted, vm_fault_t will become a distinct type.

commit 1c8f422059 ("mm: change return type to vm_fault_t")

Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com>
Reviewed-by: Matthew Wilcox <mawilcox@microsoft.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-06-01 19:18:25 +02:00
Paolo Bonzini
5eec43a1fa KVM/ARM updates for 4.18
- Lazy context-switching of FPSIMD registers on arm64
 - Allow virtual redistributors to be part of two or more MMIO ranges
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Merge tag 'kvmarm-for-v4.18' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD

KVM/ARM updates for 4.18

- Lazy context-switching of FPSIMD registers on arm64
- Allow virtual redistributors to be part of two or more MMIO ranges
2018-06-01 19:17:22 +02:00
Vitaly Kuznetsov
7053df4edb KVM: introduce kvm_make_vcpus_request_mask() API
Hyper-V style PV TLB flush hypercalls inmplementation will use this API.
To avoid memory allocation in CONFIG_CPUMASK_OFFSTACK case add
cpumask_var_t argument.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2018-05-26 14:14:33 +02:00
Christoffer Dall
bd2a6394fd KVM: arm/arm64: Introduce kvm_arch_vcpu_run_pid_change
KVM/ARM differs from other architectures in having to maintain an
additional virtual address space from that of the host and the
guest, because we split the execution of KVM across both EL1 and
EL2.

This results in a need to explicitly map data structures into EL2
(hyp) which are accessed from the hyp code.  As we are about to be
more clever with our FPSIMD handling on arm64, which stores data in
the task struct and uses thread_info flags, we will have to map
parts of the currently executing task struct into the EL2 virtual
address space.

However, we don't want to do this on every KVM_RUN, because it is a
fairly expensive operation to walk the page tables, and the common
execution mode is to map a single thread to a VCPU.  By introducing
a hook that architectures can select with
HAVE_KVM_VCPU_RUN_PID_CHANGE, we do not introduce overhead for
other architectures, but have a simple way to only map the data we
need when required for arm64.

This patch introduces the framework only, and wires it up in the
arm/arm64 KVM common code.

No functional change.

Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-05-25 12:27:54 +01:00
Gal Hammer
d4c67a7a54 kvm: use insert sort in kvm_io_bus_register_dev function
The loading time of a VM is quite significant with a CPU usage
reaching 100% when loading a VM that its virtio devices use a
large amount of virt-queues (e.g. a virtio-serial device with
max_ports=511). Most of the time is spend in re-sorting the
kvm_io_bus kvm_io_range array when a new eventfd is registered.

The patch replaces the existing method with an insert sort.

Reviewed-by: Marcel Apfelbaum <marcel@redhat.com>
Reviewed-by: Uri Lublin <ulublin@redhat.com>
Signed-off-by: Gal Hammer <ghammer@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2018-03-06 18:40:44 +01:00
Wanpeng Li
b28676bb8a KVM: mmu: Fix overlap between public and private memslots
Reported by syzkaller:

    pte_list_remove: ffff9714eb1f8078 0->BUG
    ------------[ cut here ]------------
    kernel BUG at arch/x86/kvm/mmu.c:1157!
    invalid opcode: 0000 [#1] SMP
    RIP: 0010:pte_list_remove+0x11b/0x120 [kvm]
    Call Trace:
     drop_spte+0x83/0xb0 [kvm]
     mmu_page_zap_pte+0xcc/0xe0 [kvm]
     kvm_mmu_prepare_zap_page+0x81/0x4a0 [kvm]
     kvm_mmu_invalidate_zap_all_pages+0x159/0x220 [kvm]
     kvm_arch_flush_shadow_all+0xe/0x10 [kvm]
     kvm_mmu_notifier_release+0x6c/0xa0 [kvm]
     ? kvm_mmu_notifier_release+0x5/0xa0 [kvm]
     __mmu_notifier_release+0x79/0x110
     ? __mmu_notifier_release+0x5/0x110
     exit_mmap+0x15a/0x170
     ? do_exit+0x281/0xcb0
     mmput+0x66/0x160
     do_exit+0x2c9/0xcb0
     ? __context_tracking_exit.part.5+0x4a/0x150
     do_group_exit+0x50/0xd0
     SyS_exit_group+0x14/0x20
     do_syscall_64+0x73/0x1f0
     entry_SYSCALL64_slow_path+0x25/0x25

The reason is that when creates new memslot, there is no guarantee for new
memslot not overlap with private memslots. This can be triggered by the
following program:

   #include <fcntl.h>
   #include <pthread.h>
   #include <setjmp.h>
   #include <signal.h>
   #include <stddef.h>
   #include <stdint.h>
   #include <stdio.h>
   #include <stdlib.h>
   #include <string.h>
   #include <sys/ioctl.h>
   #include <sys/stat.h>
   #include <sys/syscall.h>
   #include <sys/types.h>
   #include <unistd.h>
   #include <linux/kvm.h>

   long r[16];

   int main()
   {
	void *p = valloc(0x4000);

	r[2] = open("/dev/kvm", 0);
	r[3] = ioctl(r[2], KVM_CREATE_VM, 0x0ul);

	uint64_t addr = 0xf000;
	ioctl(r[3], KVM_SET_IDENTITY_MAP_ADDR, &addr);
	r[6] = ioctl(r[3], KVM_CREATE_VCPU, 0x0ul);
	ioctl(r[3], KVM_SET_TSS_ADDR, 0x0ul);
	ioctl(r[6], KVM_RUN, 0);
	ioctl(r[6], KVM_RUN, 0);

	struct kvm_userspace_memory_region mr = {
		.slot = 0,
		.flags = KVM_MEM_LOG_DIRTY_PAGES,
		.guest_phys_addr = 0xf000,
		.memory_size = 0x4000,
		.userspace_addr = (uintptr_t) p
	};
	ioctl(r[3], KVM_SET_USER_MEMORY_REGION, &mr);
	return 0;
   }

This patch fixes the bug by not adding a new memslot even if it
overlaps with private memslots.

Reported-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Eric Biggers <ebiggers3@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
---
 virt/kvm/kvm_main.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)
2018-02-24 01:43:36 +01:00
Linus Torvalds
15303ba5d1 KVM changes for 4.16
ARM:
 - Include icache invalidation optimizations, improving VM startup time
 
 - Support for forwarded level-triggered interrupts, improving
   performance for timers and passthrough platform devices
 
 - A small fix for power-management notifiers, and some cosmetic changes
 
 PPC:
 - Add MMIO emulation for vector loads and stores
 
 - Allow HPT guests to run on a radix host on POWER9 v2.2 CPUs without
   requiring the complex thread synchronization of older CPU versions
 
 - Improve the handling of escalation interrupts with the XIVE interrupt
   controller
 
 - Support decrement register migration
 
 - Various cleanups and bugfixes.
 
 s390:
 - Cornelia Huck passed maintainership to Janosch Frank
 
 - Exitless interrupts for emulated devices
 
 - Cleanup of cpuflag handling
 
 - kvm_stat counter improvements
 
 - VSIE improvements
 
 - mm cleanup
 
 x86:
 - Hypervisor part of SEV
 
 - UMIP, RDPID, and MSR_SMI_COUNT emulation
 
 - Paravirtualized TLB shootdown using the new KVM_VCPU_PREEMPTED bit
 
 - Allow guests to see TOPOEXT, GFNI, VAES, VPCLMULQDQ, and more AVX512
   features
 
 - Show vcpu id in its anonymous inode name
 
 - Many fixes and cleanups
 
 - Per-VCPU MSR bitmaps (already merged through x86/pti branch)
 
 - Stable KVM clock when nesting on Hyper-V (merged through x86/hyperv)
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Merge tag 'kvm-4.16-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull KVM updates from Radim Krčmář:
 "ARM:

   - icache invalidation optimizations, improving VM startup time

   - support for forwarded level-triggered interrupts, improving
     performance for timers and passthrough platform devices

   - a small fix for power-management notifiers, and some cosmetic
     changes

  PPC:

   - add MMIO emulation for vector loads and stores

   - allow HPT guests to run on a radix host on POWER9 v2.2 CPUs without
     requiring the complex thread synchronization of older CPU versions

   - improve the handling of escalation interrupts with the XIVE
     interrupt controller

   - support decrement register migration

   - various cleanups and bugfixes.

  s390:

   - Cornelia Huck passed maintainership to Janosch Frank

   - exitless interrupts for emulated devices

   - cleanup of cpuflag handling

   - kvm_stat counter improvements

   - VSIE improvements

   - mm cleanup

  x86:

   - hypervisor part of SEV

   - UMIP, RDPID, and MSR_SMI_COUNT emulation

   - paravirtualized TLB shootdown using the new KVM_VCPU_PREEMPTED bit

   - allow guests to see TOPOEXT, GFNI, VAES, VPCLMULQDQ, and more
     AVX512 features

   - show vcpu id in its anonymous inode name

   - many fixes and cleanups

   - per-VCPU MSR bitmaps (already merged through x86/pti branch)

   - stable KVM clock when nesting on Hyper-V (merged through
     x86/hyperv)"

* tag 'kvm-4.16-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (197 commits)
  KVM: PPC: Book3S: Add MMIO emulation for VMX instructions
  KVM: PPC: Book3S HV: Branch inside feature section
  KVM: PPC: Book3S HV: Make HPT resizing work on POWER9
  KVM: PPC: Book3S HV: Fix handling of secondary HPTEG in HPT resizing code
  KVM: PPC: Book3S PR: Fix broken select due to misspelling
  KVM: x86: don't forget vcpu_put() in kvm_arch_vcpu_ioctl_set_sregs()
  KVM: PPC: Book3S PR: Fix svcpu copying with preemption enabled
  KVM: PPC: Book3S HV: Drop locks before reading guest memory
  kvm: x86: remove efer_reload entry in kvm_vcpu_stat
  KVM: x86: AMD Processor Topology Information
  x86/kvm/vmx: do not use vm-exit instruction length for fast MMIO when running nested
  kvm: embed vcpu id to dentry of vcpu anon inode
  kvm: Map PFN-type memory regions as writable (if possible)
  x86/kvm: Make it compile on 32bit and with HYPYERVISOR_GUEST=n
  KVM: arm/arm64: Fixup userspace irqchip static key optimization
  KVM: arm/arm64: Fix userspace_irqchip_in_use counting
  KVM: arm/arm64: Fix incorrect timer_is_pending logic
  MAINTAINERS: update KVM/s390 maintainers
  MAINTAINERS: add Halil as additional vfio-ccw maintainer
  MAINTAINERS: add David as a reviewer for KVM/s390
  ...
2018-02-10 13:16:35 -08:00
Linus Torvalds
617aebe6a9 Currently, hardened usercopy performs dynamic bounds checking on slab
cache objects. This is good, but still leaves a lot of kernel memory
 available to be copied to/from userspace in the face of bugs. To further
 restrict what memory is available for copying, this creates a way to
 whitelist specific areas of a given slab cache object for copying to/from
 userspace, allowing much finer granularity of access control. Slab caches
 that are never exposed to userspace can declare no whitelist for their
 objects, thereby keeping them unavailable to userspace via dynamic copy
 operations. (Note, an implicit form of whitelisting is the use of constant
 sizes in usercopy operations and get_user()/put_user(); these bypass all
 hardened usercopy checks since these sizes cannot change at runtime.)
 
 This new check is WARN-by-default, so any mistakes can be found over the
 next several releases without breaking anyone's system.
 
 The series has roughly the following sections:
 - remove %p and improve reporting with offset
 - prepare infrastructure and whitelist kmalloc
 - update VFS subsystem with whitelists
 - update SCSI subsystem with whitelists
 - update network subsystem with whitelists
 - update process memory with whitelists
 - update per-architecture thread_struct with whitelists
 - update KVM with whitelists and fix ioctl bug
 - mark all other allocations as not whitelisted
 - update lkdtm for more sensible test overage
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1
 Comment: Kees Cook <kees@outflux.net>
 
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Merge tag 'usercopy-v4.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull hardened usercopy whitelisting from Kees Cook:
 "Currently, hardened usercopy performs dynamic bounds checking on slab
  cache objects. This is good, but still leaves a lot of kernel memory
  available to be copied to/from userspace in the face of bugs.

  To further restrict what memory is available for copying, this creates
  a way to whitelist specific areas of a given slab cache object for
  copying to/from userspace, allowing much finer granularity of access
  control.

  Slab caches that are never exposed to userspace can declare no
  whitelist for their objects, thereby keeping them unavailable to
  userspace via dynamic copy operations. (Note, an implicit form of
  whitelisting is the use of constant sizes in usercopy operations and
  get_user()/put_user(); these bypass all hardened usercopy checks since
  these sizes cannot change at runtime.)

  This new check is WARN-by-default, so any mistakes can be found over
  the next several releases without breaking anyone's system.

  The series has roughly the following sections:
   - remove %p and improve reporting with offset
   - prepare infrastructure and whitelist kmalloc
   - update VFS subsystem with whitelists
   - update SCSI subsystem with whitelists
   - update network subsystem with whitelists
   - update process memory with whitelists
   - update per-architecture thread_struct with whitelists
   - update KVM with whitelists and fix ioctl bug
   - mark all other allocations as not whitelisted
   - update lkdtm for more sensible test overage"

* tag 'usercopy-v4.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: (38 commits)
  lkdtm: Update usercopy tests for whitelisting
  usercopy: Restrict non-usercopy caches to size 0
  kvm: x86: fix KVM_XEN_HVM_CONFIG ioctl
  kvm: whitelist struct kvm_vcpu_arch
  arm: Implement thread_struct whitelist for hardened usercopy
  arm64: Implement thread_struct whitelist for hardened usercopy
  x86: Implement thread_struct whitelist for hardened usercopy
  fork: Provide usercopy whitelisting for task_struct
  fork: Define usercopy region in thread_stack slab caches
  fork: Define usercopy region in mm_struct slab caches
  net: Restrict unwhitelisted proto caches to size 0
  sctp: Copy struct sctp_sock.autoclose to userspace using put_user()
  sctp: Define usercopy region in SCTP proto slab cache
  caif: Define usercopy region in caif proto slab cache
  ip: Define usercopy region in IP proto slab cache
  net: Define usercopy region in struct proto slab cache
  scsi: Define usercopy region in scsi_sense_cache slab cache
  cifs: Define usercopy region in cifs_request slab cache
  vxfs: Define usercopy region in vxfs_inode slab cache
  ufs: Define usercopy region in ufs_inode_cache slab cache
  ...
2018-02-03 16:25:42 -08:00
David Rientjes
5ff7091f5a mm, mmu_notifier: annotate mmu notifiers with blockable invalidate callbacks
Commit 4d4bbd8526 ("mm, oom_reaper: skip mm structs with mmu
notifiers") prevented the oom reaper from unmapping private anonymous
memory with the oom reaper when the oom victim mm had mmu notifiers
registered.

The rationale is that doing mmu_notifier_invalidate_range_{start,end}()
around the unmap_page_range(), which is needed, can block and the oom
killer will stall forever waiting for the victim to exit, which may not
be possible without reaping.

That concern is real, but only true for mmu notifiers that have
blockable invalidate_range_{start,end}() callbacks.  This patch adds a
"flags" field to mmu notifier ops that can set a bit to indicate that
these callbacks do not block.

The implementation is steered toward an expensive slowpath, such as
after the oom reaper has grabbed mm->mmap_sem of a still alive oom
victim.

[rientjes@google.com: mmu_notifier_invalidate_range_end() can also call the invalidate_range() must not block, fix comment]
  Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1801091339570.240101@chino.kir.corp.google.com
[akpm@linux-foundation.org: make mm_has_blockable_invalidate_notifiers() return bool, use rwsem_is_locked()]
Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1712141329500.74052@chino.kir.corp.google.com
Signed-off-by: David Rientjes <rientjes@google.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: Christian König <christian.koenig@amd.com>
Acked-by: Dimitri Sivanich <sivanich@hpe.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Oded Gabbay <oded.gabbay@gmail.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Doug Ledford <dledford@redhat.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Mike Marciniszyn <mike.marciniszyn@intel.com>
Cc: Sean Hefty <sean.hefty@intel.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-01-31 17:18:38 -08:00
Linus Torvalds
5a87e37ee0 Merge branch 'work.get_user_pages_fast' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull get_user_pages_fast updates from Al Viro:
 "A bit more get_user_pages work"

* 'work.get_user_pages_fast' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  kvm: switch get_user_page_nowait() to get_user_pages_unlocked()
  __get_user_pages_locked(): get rid of notify_drop argument
  get_user_pages_unlocked(): pass true to __get_user_pages_locked() notify_drop
  cris: switch to get_user_pages_fast()
  fold __get_user_pages_unlocked() into its sole remaining caller
2018-01-31 10:01:08 -08:00
Masatake YAMATO
e46b469278 kvm: embed vcpu id to dentry of vcpu anon inode
All d-entries for vcpu have the same, "anon_inode:kvm-vcpu". That means
it is impossible to know the mapping between fds for vcpu and vcpu
from userland.

    # LC_ALL=C ls -l /proc/617/fd | grep vcpu
    lrwx------. 1 qemu qemu 64 Jan  7 16:50 18 -> anon_inode:kvm-vcpu
    lrwx------. 1 qemu qemu 64 Jan  7 16:50 19 -> anon_inode:kvm-vcpu

It is also impossible to know the mapping between vma for kvm_run
structure and vcpu from userland.

    # LC_ALL=C grep vcpu /proc/617/maps
    7f9d842d0000-7f9d842d3000 rw-s 00000000 00:0d 20393                      anon_inode:kvm-vcpu
    7f9d842d3000-7f9d842d6000 rw-s 00000000 00:0d 20393                      anon_inode:kvm-vcpu

This change adds vcpu id to d-entries for vcpu. With this change
you can get the following output:

    # LC_ALL=C ls -l /proc/617/fd | grep vcpu
    lrwx------. 1 qemu qemu 64 Jan  7 16:50 18 -> anon_inode:kvm-vcpu:0
    lrwx------. 1 qemu qemu 64 Jan  7 16:50 19 -> anon_inode:kvm-vcpu:1

    # LC_ALL=C grep vcpu /proc/617/maps
    7f9d842d0000-7f9d842d3000 rw-s 00000000 00:0d 20393                      anon_inode:kvm-vcpu:0
    7f9d842d3000-7f9d842d6000 rw-s 00000000 00:0d 20393                      anon_inode:kvm-vcpu:1

With the mappings known from the output, a tool like strace can report more details
of qemu-kvm process activities. Here is the strace output of my local prototype:

    # ./strace -KK -f -p 617 2>&1 | grep 'KVM_RUN\| K'
    ...
    [pid   664] ioctl(18, KVM_RUN, 0)       = 0 (KVM_EXIT_MMIO)
     K ready_for_interrupt_injection=1, if_flag=0, flags=0, cr8=0000000000000000, apic_base=0x000000fee00d00
     K phys_addr=0, len=1634035803, [33, 0, 0, 0, 0, 0, 0, 0], is_write=112
    [pid   664] ioctl(18, KVM_RUN, 0)       = 0 (KVM_EXIT_MMIO)
     K ready_for_interrupt_injection=1, if_flag=1, flags=0, cr8=0000000000000000, apic_base=0x000000fee00d00
     K phys_addr=0, len=1634035803, [33, 0, 0, 0, 0, 0, 0, 0], is_write=112
    ...

Signed-off-by: Masatake YAMATO <yamato@redhat.com>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2018-01-31 18:25:34 +01:00
KarimAllah Ahmed
a340b3e229 kvm: Map PFN-type memory regions as writable (if possible)
For EPT-violations that are triggered by a read, the pages are also mapped with
write permissions (if their memory region is also writable). That would avoid
getting yet another fault on the same page when a write occurs.

This optimization only happens when you have a "struct page" backing the memory
region. So also enable it for memory regions that do not have a "struct page".

Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: kvm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: KarimAllah Ahmed <karahmed@amazon.de>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2018-01-31 18:25:33 +01:00
Paolo Bonzini
46515736f8 kvm: whitelist struct kvm_vcpu_arch
On x86, ARM and s390, struct kvm_vcpu_arch has a usercopy region
that is read and written by the KVM_GET/SET_CPUID2 ioctls (x86)
or KVM_GET/SET_ONE_REG (ARM/s390).  Without whitelisting the area,
KVM is completely broken on those architectures with usercopy hardening
enabled.

For now, allow writing to the entire struct on all architectures.
The KVM tree will not refine this to an architecture-specific
subset of struct kvm_vcpu_arch.

Cc: kernel-hardening@lists.openwall.com
Cc: Kees Cook <keescook@chromium.org>
Cc: Christian Borntraeger <borntraeger@redhat.com>
Cc: Christoffer Dall <cdall@linaro.org>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
2018-01-15 12:08:07 -08:00
Paolo Bonzini
5cb0944c0c KVM: introduce kvm_arch_vcpu_async_ioctl
After the vcpu_load/vcpu_put pushdown, the handling of asynchronous VCPU
ioctl is already much clearer in that it is obvious that they bypass
vcpu_load and vcpu_put.

However, it is still not perfect in that the different state of the VCPU
mutex is still hidden in the caller.  Separate those ioctls into a new
function kvm_arch_vcpu_async_ioctl that returns -ENOIOCTLCMD for more
"traditional" synchronous ioctls.

Cc: James Hogan <jhogan@kernel.org>
Cc: Paul Mackerras <paulus@ozlabs.org>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Suggested-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-12-14 09:26:59 +01:00
Christoffer Dall
9b062471e5 KVM: Move vcpu_load to arch-specific kvm_arch_vcpu_ioctl
Move the calls to vcpu_load() and vcpu_put() in to the architecture
specific implementations of kvm_arch_vcpu_ioctl() which dispatches
further architecture-specific ioctls on to other functions.

Some architectures support asynchronous vcpu ioctls which cannot call
vcpu_load() or take the vcpu->mutex, because that would prevent
concurrent execution with a running VCPU, which is the intended purpose
of these ioctls, for example because they inject interrupts.

We repeat the separate checks for these specifics in the architecture
code for MIPS, S390 and PPC, and avoid taking the vcpu->mutex and
calling vcpu_load for these ioctls.

Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-12-14 09:26:58 +01:00
Christoffer Dall
6a96bc7fa0 KVM: Move vcpu_load to arch-specific kvm_arch_vcpu_ioctl_set_fpu
Move vcpu_load() and vcpu_put() into the architecture specific
implementations of kvm_arch_vcpu_ioctl_set_fpu().

Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-12-14 09:26:57 +01:00
Christoffer Dall
1393123e1e KVM: Move vcpu_load to arch-specific kvm_arch_vcpu_ioctl_get_fpu
Move vcpu_load() and vcpu_put() into the architecture specific
implementations of kvm_arch_vcpu_ioctl_get_fpu().

Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-12-14 09:26:56 +01:00
Christoffer Dall
66b5656222 KVM: Move vcpu_load to arch-specific kvm_arch_vcpu_ioctl_set_guest_debug
Move vcpu_load() and vcpu_put() into the architecture specific
implementations of kvm_arch_vcpu_ioctl_set_guest_debug().

Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-12-14 09:26:56 +01:00
Christoffer Dall
1da5b61dac KVM: Move vcpu_load to arch-specific kvm_arch_vcpu_ioctl_translate
Move vcpu_load() and vcpu_put() into the architecture specific
implementations of kvm_arch_vcpu_ioctl_translate().

Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-12-14 09:26:55 +01:00
Christoffer Dall
e83dff5edf KVM: Move vcpu_load to arch-specific kvm_arch_vcpu_ioctl_set_mpstate
Move vcpu_load() and vcpu_put() into the architecture specific
implementations of kvm_arch_vcpu_ioctl_set_mpstate().

Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-12-14 09:26:54 +01:00
Christoffer Dall
fd2325612c KVM: Move vcpu_load to arch-specific kvm_arch_vcpu_ioctl_get_mpstate
Move vcpu_load() and vcpu_put() into the architecture specific
implementations of kvm_arch_vcpu_ioctl_get_mpstate().

Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-12-14 09:26:54 +01:00
Christoffer Dall
b4ef9d4e8c KVM: Move vcpu_load to arch-specific kvm_arch_vcpu_ioctl_set_sregs
Move vcpu_load() and vcpu_put() into the architecture specific
implementations of kvm_arch_vcpu_ioctl_set_sregs().

Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-12-14 09:26:53 +01:00
Christoffer Dall
bcdec41cef KVM: Move vcpu_load to arch-specific kvm_arch_vcpu_ioctl_get_sregs
Move vcpu_load() and vcpu_put() into the architecture specific
implementations of kvm_arch_vcpu_ioctl_get_sregs().

Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-12-14 09:26:52 +01:00
Christoffer Dall
875656fe0c KVM: Move vcpu_load to arch-specific kvm_arch_vcpu_ioctl_set_regs
Move vcpu_load() and vcpu_put() into the architecture specific
implementations of kvm_arch_vcpu_ioctl_set_regs().

Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-12-14 09:26:52 +01:00
Christoffer Dall
1fc9b76b3d KVM: Move vcpu_load to arch-specific kvm_arch_vcpu_ioctl_get_regs
Move vcpu_load() and vcpu_put() into the architecture specific
implementations of kvm_arch_vcpu_ioctl_get_regs().

Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-12-14 09:26:51 +01:00
Christoffer Dall
accb757d79 KVM: Move vcpu_load to arch-specific kvm_arch_vcpu_ioctl_run
Move vcpu_load() and vcpu_put() into the architecture specific
implementations of kvm_arch_vcpu_ioctl_run().

Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> # s390 parts
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
[Rebased. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-12-14 09:26:50 +01:00
Christoffer Dall
8a32dd60ec KVM: Prepare for moving vcpu_load/vcpu_put into arch specific code
In preparation for moving calls to vcpu_load() and vcpu_put() into the
architecture specific implementations of the KVM vcpu ioctls, move the
calls in the main kvm_vcpu_ioctl() dispatcher function to each case
of the ioctl select statement.  This allows us to move the vcpu_load()
and vcpu_put() calls into architecture specific implementations of vcpu
ioctls, one by one.

Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-12-14 09:26:50 +01:00
Christoffer Dall
ec7660ccdd KVM: Take vcpu->mutex outside vcpu_load
As we're about to call vcpu_load() from architecture-specific
implementations of the KVM vcpu ioctls, but yet we access data
structures protected by the vcpu->mutex in the generic code, factor
this logic out from vcpu_load().

x86 is the only architecture which calls vcpu_load() outside of the main
vcpu ioctl function, and these calls will no longer take the vcpu mutex
following this patch.  However, with the exception of
kvm_arch_vcpu_postcreate (see below), the callers are either in the
creation or destruction path of the VCPU, which means there cannot be
any concurrent access to the data structure, because the file descriptor
is not yet accessible, or is already gone.

kvm_arch_vcpu_postcreate makes the newly created vcpu potentially
accessible by other in-kernel threads through the kvm->vcpus array, and
we therefore take the vcpu mutex in this case directly.

Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-12-14 09:26:49 +01:00