10 Commits

Author SHA1 Message Date
Colin Xu
a291e4fba2 drm/i915/gvt: Use GFP_ATOMIC instead of GFP_KERNEL in atomic context
GFP_KERNEL flag specifies a normal kernel allocation in which executing
in process context without any locks and can sleep.
mmio_diff takes sometime to finish all the diff compare and it has
locks, continue using GFP_KERNEL will output below trace if LOCKDEP
enabled.

Use GFP_ATOMIC instead.

V2: Rebase.

=====================================================
WARNING: SOFTIRQ-safe -> SOFTIRQ-unsafe lock order detected
5.7.0-rc2 #400 Not tainted
-----------------------------------------------------
is trying to acquire:
ffffffffb47bea20 (fs_reclaim){+.+.}-{0:0}, at: fs_reclaim_acquire.part.0+0x0/0x30

               and this task is already holding:
ffff88845b85cc90 (&gvt->scheduler.mmio_context_lock){+.-.}-{2:2}, at: vgpu_mmio_diff_show+0xcf/0x2e0
which would create a new lock dependency:
 (&gvt->scheduler.mmio_context_lock){+.-.}-{2:2} -> (fs_reclaim){+.+.}-{0:0}

               but this new dependency connects a SOFTIRQ-irq-safe lock:
 (&gvt->scheduler.mmio_context_lock){+.-.}-{2:2}

               ... which became SOFTIRQ-irq-safe at:
  lock_acquire+0x175/0x4e0
  _raw_spin_lock_irqsave+0x2b/0x40
  shadow_context_status_change+0xfe/0x2f0
  notifier_call_chain+0x6a/0xa0
  __atomic_notifier_call_chain+0x5f/0xf0
  execlists_schedule_out+0x42a/0x820
  process_csb+0xe7/0x3e0
  execlists_submission_tasklet+0x5c/0x1d0
  tasklet_action_common.isra.0+0xeb/0x260
  __do_softirq+0x11d/0x56f
  irq_exit+0xf6/0x100
  do_IRQ+0x7f/0x160
  ret_from_intr+0x0/0x2a
  cpuidle_enter_state+0xcd/0x5b0
  cpuidle_enter+0x37/0x60
  do_idle+0x337/0x3f0
  cpu_startup_entry+0x14/0x20
  start_kernel+0x58b/0x5c5
  secondary_startup_64+0xa4/0xb0

               to a SOFTIRQ-irq-unsafe lock:
 (fs_reclaim){+.+.}-{0:0}

               ... which became SOFTIRQ-irq-unsafe at:
...
  lock_acquire+0x175/0x4e0
  fs_reclaim_acquire.part.0+0x20/0x30
  kmem_cache_alloc_node_trace+0x2e/0x290
  alloc_worker+0x2b/0xb0
  init_rescuer.part.0+0x17/0xe0
  workqueue_init+0x293/0x3bb
  kernel_init_freeable+0x149/0x325
  kernel_init+0x8/0x116
  ret_from_fork+0x3a/0x50

               other info that might help us debug this:

 Possible interrupt unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(fs_reclaim);
                               local_irq_disable();
                               lock(&gvt->scheduler.mmio_context_lock);
                               lock(fs_reclaim);
  <Interrupt>
    lock(&gvt->scheduler.mmio_context_lock);

                *** DEADLOCK ***

3 locks held by cat/1439:
 #0: ffff888444a23698 (&p->lock){+.+.}-{3:3}, at: seq_read+0x49/0x680
 #1: ffff88845b858068 (&gvt->lock){+.+.}-{3:3}, at: vgpu_mmio_diff_show+0xc7/0x2e0
 #2: ffff88845b85cc90 (&gvt->scheduler.mmio_context_lock){+.-.}-{2:2}, at: vgpu_mmio_diff_show+0xcf/0x2e0

               the dependencies between SOFTIRQ-irq-safe lock and the holding lock:
-> (&gvt->scheduler.mmio_context_lock){+.-.}-{2:2} ops: 31 {
   HARDIRQ-ON-W at:
                    lock_acquire+0x175/0x4e0
                    _raw_spin_lock_bh+0x2f/0x40
                    vgpu_mmio_diff_show+0xcf/0x2e0
                    seq_read+0x242/0x680
                    full_proxy_read+0x95/0xc0
                    vfs_read+0xc2/0x1b0
                    ksys_read+0xc4/0x160
                    do_syscall_64+0x63/0x290
                    entry_SYSCALL_64_after_hwframe+0x49/0xb3
   IN-SOFTIRQ-W at:
                    lock_acquire+0x175/0x4e0
                    _raw_spin_lock_irqsave+0x2b/0x40
                    shadow_context_status_change+0xfe/0x2f0
                    notifier_call_chain+0x6a/0xa0
                    __atomic_notifier_call_chain+0x5f/0xf0
                    execlists_schedule_out+0x42a/0x820
                    process_csb+0xe7/0x3e0
                    execlists_submission_tasklet+0x5c/0x1d0
                    tasklet_action_common.isra.0+0xeb/0x260
                    __do_softirq+0x11d/0x56f
                    irq_exit+0xf6/0x100
                    do_IRQ+0x7f/0x160
                    ret_from_intr+0x0/0x2a
                    cpuidle_enter_state+0xcd/0x5b0
                    cpuidle_enter+0x37/0x60
                    do_idle+0x337/0x3f0
                    cpu_startup_entry+0x14/0x20
                    start_kernel+0x58b/0x5c5
                    secondary_startup_64+0xa4/0xb0
   INITIAL USE at:
                   lock_acquire+0x175/0x4e0
                   _raw_spin_lock_irqsave+0x2b/0x40
                   shadow_context_status_change+0xfe/0x2f0
                   notifier_call_chain+0x6a/0xa0
                   __atomic_notifier_call_chain+0x5f/0xf0
                   execlists_schedule_in+0x2c8/0x690
                   __execlists_submission_tasklet+0x1303/0x1930
                   execlists_submit_request+0x1e7/0x230
                   submit_notify+0x105/0x2a4
                   __i915_sw_fence_complete+0xaa/0x380
                   __engine_park+0x313/0x5a0
                   ____intel_wakeref_put_last+0x3e/0x90
                   intel_gt_resume+0x41e/0x440
                   intel_gt_init+0x283/0xbc0
                   i915_gem_init+0x197/0x240
                   i915_driver_probe+0xc2d/0x12e0
                   i915_pci_probe+0xa2/0x1e0
                   local_pci_probe+0x6f/0xb0
                   pci_device_probe+0x171/0x230
                   really_probe+0x17a/0x380
                   driver_probe_device+0x70/0xf0
                   device_driver_attach+0x82/0x90
                   __driver_attach+0x60/0x100
                   bus_for_each_dev+0xe4/0x140
                   bus_add_driver+0x257/0x2a0
                   driver_register+0xd3/0x150
                   i915_init+0x6d/0x80
                   do_one_initcall+0xb8/0x3a0
                   kernel_init_freeable+0x2b4/0x325
                   kernel_init+0x8/0x116
                   ret_from_fork+0x3a/0x50
 }
__key.77812+0x0/0x40
 ... acquired at:
   lock_acquire+0x175/0x4e0
   fs_reclaim_acquire.part.0+0x20/0x30
   kmem_cache_alloc_trace+0x2e/0x260
   mmio_diff_handler+0xc0/0x150
   intel_gvt_for_each_tracked_mmio+0x7b/0x140
   vgpu_mmio_diff_show+0x111/0x2e0
   seq_read+0x242/0x680
   full_proxy_read+0x95/0xc0
   vfs_read+0xc2/0x1b0
   ksys_read+0xc4/0x160
   do_syscall_64+0x63/0x290
   entry_SYSCALL_64_after_hwframe+0x49/0xb3

               the dependencies between the lock to be acquired
 and SOFTIRQ-irq-unsafe lock:
-> (fs_reclaim){+.+.}-{0:0} ops: 1999031 {
   HARDIRQ-ON-W at:
                    lock_acquire+0x175/0x4e0
                    fs_reclaim_acquire.part.0+0x20/0x30
                    kmem_cache_alloc_node_trace+0x2e/0x290
                    alloc_worker+0x2b/0xb0
                    init_rescuer.part.0+0x17/0xe0
                    workqueue_init+0x293/0x3bb
                    kernel_init_freeable+0x149/0x325
                    kernel_init+0x8/0x116
                    ret_from_fork+0x3a/0x50
   SOFTIRQ-ON-W at:
                    lock_acquire+0x175/0x4e0
                    fs_reclaim_acquire.part.0+0x20/0x30
                    kmem_cache_alloc_node_trace+0x2e/0x290
                    alloc_worker+0x2b/0xb0
                    init_rescuer.part.0+0x17/0xe0
                    workqueue_init+0x293/0x3bb
                    kernel_init_freeable+0x149/0x325
                    kernel_init+0x8/0x116
                    ret_from_fork+0x3a/0x50
   INITIAL USE at:
                   lock_acquire+0x175/0x4e0
                   fs_reclaim_acquire.part.0+0x20/0x30
                   kmem_cache_alloc_node_trace+0x2e/0x290
                   alloc_worker+0x2b/0xb0
                   init_rescuer.part.0+0x17/0xe0
                   workqueue_init+0x293/0x3bb
                   kernel_init_freeable+0x149/0x325
                   kernel_init+0x8/0x116
                   ret_from_fork+0x3a/0x50
 }
__fs_reclaim_map+0x0/0x60
 ... acquired at:
   lock_acquire+0x175/0x4e0
   fs_reclaim_acquire.part.0+0x20/0x30
   kmem_cache_alloc_trace+0x2e/0x260
   mmio_diff_handler+0xc0/0x150
   intel_gvt_for_each_tracked_mmio+0x7b/0x140
   vgpu_mmio_diff_show+0x111/0x2e0
   seq_read+0x242/0x680
   full_proxy_read+0x95/0xc0
   vfs_read+0xc2/0x1b0
   ksys_read+0xc4/0x160
   do_syscall_64+0x63/0x290
   entry_SYSCALL_64_after_hwframe+0x49/0xb3

               stack backtrace:
CPU: 5 PID: 1439 Comm: cat Not tainted 5.7.0-rc2 #400
Hardware name: Intel(R) Client Systems NUC8i7BEH/NUC8BEB, BIOS BECFL357.86A.0056.2018.1128.1717 11/28/2018
Call Trace:
 dump_stack+0x97/0xe0
 check_irq_usage.cold+0x428/0x434
 ? check_usage_forwards+0x2c0/0x2c0
 ? class_equal+0x11/0x20
 ? __bfs+0xd2/0x2d0
 ? in_any_class_list+0xa0/0xa0
 ? check_path+0x22/0x40
 ? check_noncircular+0x150/0x2b0
 ? print_circular_bug.isra.0+0x1b0/0x1b0
 ? mark_lock+0x13d/0xc50
 ? __lock_acquire+0x1e32/0x39b0
 __lock_acquire+0x1e32/0x39b0
 ? timerqueue_add+0xc1/0x130
 ? register_lock_class+0xa60/0xa60
 ? mark_lock+0x13d/0xc50
 lock_acquire+0x175/0x4e0
 ? __zone_pcp_update+0x80/0x80
 ? check_flags.part.0+0x210/0x210
 ? mark_held_locks+0x65/0x90
 ? _raw_spin_unlock_irqrestore+0x32/0x40
 ? lockdep_hardirqs_on+0x190/0x290
 ? fwtable_read32+0x163/0x480
 ? mmio_diff_handler+0xc0/0x150
 fs_reclaim_acquire.part.0+0x20/0x30
 ? __zone_pcp_update+0x80/0x80
 kmem_cache_alloc_trace+0x2e/0x260
 mmio_diff_handler+0xc0/0x150
 ? vgpu_mmio_diff_open+0x30/0x30
 intel_gvt_for_each_tracked_mmio+0x7b/0x140
 vgpu_mmio_diff_show+0x111/0x2e0
 ? mmio_diff_handler+0x150/0x150
 ? rcu_read_lock_sched_held+0xa0/0xb0
 ? rcu_read_lock_bh_held+0xc0/0xc0
 ? kasan_unpoison_shadow+0x33/0x40
 ? __kasan_kmalloc.constprop.0+0xc2/0xd0
 seq_read+0x242/0x680
 ? debugfs_locked_down.isra.0+0x70/0x70
 full_proxy_read+0x95/0xc0
 vfs_read+0xc2/0x1b0
 ksys_read+0xc4/0x160
 ? kernel_write+0xb0/0xb0
 ? mark_held_locks+0x24/0x90
 do_syscall_64+0x63/0x290
 entry_SYSCALL_64_after_hwframe+0x49/0xb3
RIP: 0033:0x7ffbe3e6efb2
Code: c0 e9 c2 fe ff ff 50 48 8d 3d ca cb 0a 00 e8 f5 19 02 00 0f 1f 44 00 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 0f 05 <48> 3d 00 f0 ff ff 77 56 c3 0f 1f 44 00 00 48 83 ec 28 48 89 54 24
RSP: 002b:00007ffd021c08a8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 0000000000020000 RCX: 00007ffbe3e6efb2
RDX: 0000000000020000 RSI: 00007ffbe34cd000 RDI: 0000000000000003
RBP: 00007ffbe34cd000 R08: 00007ffbe34cc010 R09: 0000000000000000
R10: 0000000000000022 R11: 0000000000000246 R12: 0000562b6f0a11f0
R13: 0000000000000003 R14: 0000000000020000 R15: 0000000000020000
------------[ cut here ]------------

Acked-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: Colin Xu <colin.xu@intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20200601035556.19999-1-colin.xu@intel.com
2020-06-17 12:36:19 +08:00
Chris Wilson
a61ac1e751 drm/i915/gvt: Wean gvt off using dev_priv
Teach gvt to use intel_gt directly as it currently assumes direct HW
access.

[Zhenyu: rebase, fix compiling]

Cc: Ding Zhuocheng <zhuocheng.ding@intel.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Acked-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20200304032307.2983-3-zhenyuw@linux.intel.com
2020-03-06 10:08:10 +08:00
Chris Wilson
aa444fc7fb drm/i915/gvt: cleanup debugfs scan_nonprivbb
Remove extra chatty message for debugfs scan_nonprivbb which is used
to enable scan for non privileged batch on specific engine. Just write
target i915 engine mask instead.

Cc: Ding Zhuocheng <zhuocheng.ding@intel.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Acked-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20200304032307.2983-1-zhenyuw@linux.intel.com
2020-03-06 09:54:01 +08:00
Greg Kroah-Hartman
f8871ec8fc drm/i915/gvt: 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.

Because there is no need to check these functions, a number of local
functions can be made to return void to simplify things as nothing can
fail.

Cc: Zhenyu Wang <zhenyuw@linux.intel.com>
Cc: Zhi Wang <zhi.a.wang@intel.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: intel-gvt-dev@lists.freedesktop.org
Cc: intel-gfx@lists.freedesktop.org
Cc: dri-devel@lists.freedesktop.org
Reviewed-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
2019-08-13 17:55:06 +08:00
Tvrtko Ursulin
5a31d30b22 drm/i915: Remove I915_READ_NOTRACE
Only a few call sites remain which have been converted to uncore mmio
accessors and so the macro can be removed.

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190611104548.30545-5-tvrtko.ursulin@linux.intel.com
2019-06-12 15:33:13 +01:00
Aleksei Gimbitskii
4feeea1d8d drm/i915/gvt: Use snprintf() to prevent possible buffer overflow.
For printing the intel_vgpu->id, a buffer with fixed length is allocated
on the stack. But if vgpu->id is greater than 6 characters, the buffer
overflow will happen. Even the string of the amount of max vgpu is less
that the length buffer right now, it's better to replace sprintf() with
snprintf().

v2:
- Increase the size of the buffer. (Colin Xu)

This patch fixed the critical issue #673 reported by klocwork.

Signed-off-by: Aleksei Gimbitskii <aleksei.gimbitskii@intel.com>
Cc: Zhenyu Wang <zhenyuw@linux.intel.com>
Cc: Zhi Wang <zhi.a.wang@intel.com>
Cc: Colin Xu <colin.xu@intel.com>
Reviewed-by: Colin Xu <colin.xu@intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
2019-04-25 15:34:59 +08:00
Zhao Yan
96bebe39b2 drm/i915/gvt: scan non-privileged batch buffer for debug purpose
For perfomance purpose, scanning of non-privileged batch buffer is turned
off by default. But for debugging purpose, it can be turned on via debugfs.
After scanning, we submit the original non-privileged batch buffer into
hardware, so that the scanning is only a peeking window of guest submitted
commands and will not affect the execution results.

v4:
- refine debugfs print format&content (zhenyu wang)
- print engine id instread of engine name to prevent potential memory leak
  in debugfs warning message. (zhenyu wang)

v3:
- change vgpu->scan_nonprivbb from type bool to u32, so it is able to
  selectively turn on/off scanning of non-privileged batch buffer on engine
  level. e.g.
  if vgpu->scan_nonprivbb=3, then it will scan non-privileged batch buffer
  on engine 0 and 1.
- in debugfs interface to set vgpu->scan_nonprivbb, print warning message
  to warn user and explicitly tell state change in kernel log (zhenyu wang)
v2:
- rebase
- update comments for start_gma_offset (henry)

Signed-off-by: Zhao Yan <yan.y.zhao@intel.com>
Reviewed-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: Zhi Wang <zhi.a.wang@intel.com>
2018-04-23 13:09:34 +08:00
Andy Shevchenko
e4006713d1 i915: Re-use DEFINE_SHOW_ATTRIBUTE() macro
...instead of open coding file operations followed by custom ->open()
callbacks per each attribute.

Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20180316141213.38774-1-andriy.shevchenko@linux.intel.com
2018-03-16 15:59:49 +00:00
Changbin Du
cea9083e35 drm/i915/gvt: Add new debugfs tool mmio_diff
This new debugfs entry is used to figure out which registers of vGPU
is different to host. It is a useful tool for new platform enabling
and debugging. When read this entry, all the diff mmio are recognized
and sorted by mmio offset. Besides, the bit positions of different
value are listed in 'Diff' column. Here is a show:

$ sudo cat ./mmio_diff
Offset   HW       vGPU     Diff
00002030 000025f8 00000000 3-8,10,13
00002034 012025f8 00000000 3-8,10,13,21,24
00002038 027fb000 00000000 12-13,15-22,25
0000203c 00003000 00000000 12-13
00002054 0000000a 00000040 1,3,6
00002074 012025f8 00000000 3-8,10,13,21,24
00002080 fffe6000 00000000 13-14,17-31
000020a8 fffffeff ffffffff 8
000020d4 00000004 00000000 2
....
00145974 eb42718c 010c11b0 2-5,13-14,17-19,22,25,27,29-31
00145978 0000002f 0000002a 0,2
0014597c 0000002f 0000002a 0,2
00145980 0000002b 00000028 0-1
00145984 a5a87c9e b27d20c0 1-4,6,10-12,14,16,18,20,22-26,28
001459c0 88390000 883c0000 16,18
00146200 88350000 883a0000 16-19
Total: 72432, Diff: 901

v3: fix a typo.
v2: add mmio_hw_access_pre/post().

Signed-off-by: Changbin Du <changbin.du@intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
2017-11-16 11:48:32 +08:00
Changbin Du
bc7b0be316 drm/i915/gvt: Add basic debugfs infrastructure
We need debugfs entry to expose some debug information of gvt and vGPUs.
The first tool will be added is mmio-diff, which help to find the
difference values of host and vGPU mmio. It's useful for platform
enabling.

This patch just add a basic debugfs infrastructure, each vGPU has its own
sub-folder. Two simple attributes are created as a template.
.
├── num_tracked_mmio
├── vgpu1
|   └── active
└── vgpu2
    └── active

Signed-off-by: Changbin Du <changbin.du@intel.com>
Reviewed-by: Zhi Wang <zhi.a.wang@intel.com>
Signed-off-by: Zhi Wang <zhi.a.wang@intel.com>
2017-11-16 11:48:20 +08:00