Commit Graph

9 Commits

Author SHA1 Message Date
Ingo Molnar
b2d0910310 sched/headers: Prepare to use <linux/rcuupdate.h> instead of <linux/rculist.h> in <linux/sched.h>
We don't actually need the full rculist.h header in sched.h anymore,
we will be able to include the smaller rcupdate.h header instead.

But first update code that relied on the implicit header inclusion.

Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-02 08:42:38 +01:00
Jike Song
871b7ef2a1 kvm/page_track: export symbols for external usage
Signed-off-by: Jike Song <jike.song@intel.com>
Reviewed-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-11-04 12:13:20 +01:00
Jike Song
d126363d8f kvm/page_track: call notifiers with kvm_page_track_notifier_node
The user of page_track might needs extra information, so pass
the kvm_page_track_notifier_node to callbacks.

Signed-off-by: Jike Song <jike.song@intel.com>
Reviewed-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-11-04 12:13:20 +01:00
Xiaoguang Chen
ae7cd87372 KVM: x86: add track_flush_slot page track notifier
When a memory slot is being moved or removed users of page track
can be notified. So users can drop write-protection for the pages
in that memory slot.

This notifier type is needed by KVMGT to sync up its shadow page
table when memory slot is being moved or removed.

Register the notifier type track_flush_slot to receive memslot move
and remove event.

Reviewed-by: Xiao Guangrong <guangrong.xiao@intel.com>
Signed-off-by: Chen Xiaoguang <xiaoguang.chen@intel.com>
[Squashed commits to avoid bisection breakage and reworded the subject.]
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2016-11-04 12:13:19 +01:00
Paolo Bonzini
a6adb10622 KVM: page_track: fix access to NULL slot
This happens when doing the reboot test from virt-tests:

[  131.833653] BUG: unable to handle kernel NULL pointer dereference at           (null)
[  131.842461] IP: [<ffffffffa0950087>] kvm_page_track_is_active+0x17/0x60 [kvm]
[  131.850500] PGD 0
[  131.852763] Oops: 0000 [#1] SMP
[  132.007188] task: ffff880075fbc500 ti: ffff880850a3c000 task.ti: ffff880850a3c000
[  132.138891] Call Trace:
[  132.141639]  [<ffffffffa092bd11>] page_fault_handle_page_track+0x31/0x40 [kvm]
[  132.149732]  [<ffffffffa093380f>] paging64_page_fault+0xff/0x910 [kvm]
[  132.172159]  [<ffffffffa092c734>] kvm_mmu_page_fault+0x64/0x110 [kvm]
[  132.179372]  [<ffffffffa06743c2>] handle_exception+0x1b2/0x430 [kvm_intel]
[  132.187072]  [<ffffffffa067a301>] vmx_handle_exit+0x1e1/0xc50 [kvm_intel]
...

Cc: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Fixes: 3d0c27ad6e
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-22 17:27:28 +01:00
Xiao Guangrong
0eb05bf290 KVM: page track: add notifier support
Notifier list is introduced so that any node wants to receive the track
event can register to the list

Two APIs are introduced here:
- kvm_page_track_register_notifier(): register the notifier to receive
  track event

- kvm_page_track_unregister_notifier(): stop receiving track event by
  unregister the notifier

The callback, node->track_write() is called when a write access on the
write tracked page happens

Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-03 14:36:22 +01:00
Xiao Guangrong
3d0c27ad6e KVM: MMU: let page fault handler be aware tracked page
The page fault caused by write access on the write tracked page can not
be fixed, it always need to be emulated. page_fault_handle_page_track()
is the fast path we introduce here to skip holding mmu-lock and shadow
page table walking

However, if the page table is not present, it is worth making the page
table entry present and readonly to make the read access happy

mmu_need_write_protect() need to be cooked to avoid page becoming writable
when making page table present or sync/prefetch shadow page table entries

Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-03 14:36:21 +01:00
Xiao Guangrong
f29d4d7810 KVM: page track: introduce kvm_slot_page_track_{add,remove}_page
These two functions are the user APIs:
- kvm_slot_page_track_add_page(): add the page to the tracking pool
  after that later specified access on that page will be tracked

- kvm_slot_page_track_remove_page(): remove the page from the tracking
  pool, the specified access on the page is not tracked after the last
  user is gone

Both of these are called under the protection both of mmu-lock and
kvm->srcu or kvm->slots_lock

Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-03 14:36:21 +01:00
Xiao Guangrong
21ebbedadd KVM: page track: add the framework of guest page tracking
The array, gfn_track[mode][gfn], is introduced in memory slot for every
guest page, this is the tracking count for the gust page on different
modes. If the page is tracked then the count is increased, the page is
not tracked after the count reaches zero

We use 'unsigned short' as the tracking count which should be enough as
shadow page table only can use 2^14 (2^3 for level, 2^1 for cr4_pae, 2^2
for quadrant, 2^3 for access, 2^1 for nxe, 2^1 for cr0_wp, 2^1 for
smep_andnot_wp, 2^1 for smap_andnot_wp, and 2^1 for smm) at most, there
is enough room for other trackers

Two callbacks, kvm_page_track_create_memslot() and
kvm_page_track_free_memslot() are implemented in this patch, they are
internally used to initialize and reclaim the memory of the array

Currently, only write track mode is supported

Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-03 14:36:20 +01:00