Re: [REGRESSION] Panic in gen8_ggtt_insert_entries() with v6.5

[Bagas Sanjaya]

On Sat, Sep 02, 2023 at 06:14:12PM +0200, Oleksandr Natalenko wrote:
> Hello.
> 
> Since v6.5 kernel the following HW:
> 
> * Lenovo T460s laptop with Skylake GT2 [HD Graphics 520] (rev 07)
> * Lenovo T490s laptop with WhiskeyLake-U GT2 [UHD Graphics 620] (rev 02)
> 
> is affected by the following crash once KDE on either X11 or Wayland is started:
> 
> i915 0000:00:02.0: enabling device (0006 -> 0007)
> i915 0000:00:02.0: vgaarb: deactivate vga console
> i915 0000:00:02.0: vgaarb: changed VGA decodes: olddecodes=io+mem,decodes=io+mem:owns=mem
> i915 0000:00:02.0: [drm] Finished loading DMC firmware i915/skl_dmc_ver1_27.bin (v1.27)
> [drm] Initialized i915 1.6.0 20201103 for 0000:00:02.0 on minor 1
> fbcon: i915drmfb (fb0) is primary device
> i915 0000:00:02.0: [drm] fb0: i915drmfb frame buffer device
> …
> memfd_create() without MFD_EXEC nor MFD_NOEXEC_SEAL, pid=674 'kwin_wayland'
> BUG: unable to handle page fault for address: ffffb422c2800000
> #PF: supervisor write access in kernel mode
> #PF: error_code(0x0002) - not-present page
> PGD 100000067 P4D 100000067 PUD 1001df067 PMD 10d1cf067 PTE 0
> Oops: 0002 [#1] PREEMPT SMP PTI
> CPU: 1 PID: 674 Comm: kwin_wayland Not tainted 6.5.0-pf1 #1 a6c58ff41a7b8bb16a19f5af9e0e9bce20f9f38d
> Hardware name: LENOVO 20FAS2BM0F/20FAS2BM0F, BIOS N1CET90W (1.58 ) 11/15/2022
> RIP: 0010:gen8_ggtt_insert_entries+0xc2/0x140 [i915]
> …
> Call Trace:
>  <TASK>
>  intel_ggtt_bind_vma+0x3e/0x60 [i915 a83fdc6539431252dba13053979a8b680af86836]
>  i915_vma_bind+0x216/0x4b0 [i915 a83fdc6539431252dba13053979a8b680af86836]
>  i915_vma_pin_ww+0x405/0xa80 [i915 a83fdc6539431252dba13053979a8b680af86836]
>  __i915_ggtt_pin+0x5a/0x130 [i915 a83fdc6539431252dba13053979a8b680af86836]
>  i915_ggtt_pin+0x78/0x1f0 [i915 a83fdc6539431252dba13053979a8b680af86836]
>  __intel_context_do_pin_ww+0x312/0x700 [i915 a83fdc6539431252dba13053979a8b680af86836]
>  i915_gem_do_execbuffer+0xfc6/0x2720 [i915 a83fdc6539431252dba13053979a8b680af86836]
>  i915_gem_execbuffer2_ioctl+0x111/0x260 [i915 a83fdc6539431252dba13053979a8b680af86836]
>  drm_ioctl_kernel+0xca/0x170
>  drm_ioctl+0x30f/0x580
>  __x64_sys_ioctl+0x94/0xd0
>  do_syscall_64+0x5d/0x90
>  entry_SYSCALL_64_after_hwframe+0x6e/0xd8
> …
> note: kwin_wayland[674] exited with irqs disabled
> 
> RIP seems to translate into this:
> 
> $ scripts/faddr2line drivers/gpu/drm/i915/gt/intel_ggtt.o gen8_ggtt_insert_entries+0xc2
> gen8_ggtt_insert_entries+0xc2/0x150:
> writeq at /home/pf/work/devel/own/pf-kernel/linux/./arch/x86/include/asm/io.h:99
> (inlined by) gen8_set_pte at /home/pf/work/devel/own/pf-kernel/linux/drivers/gpu/drm/i915/gt/intel_ggtt.c:257
> (inlined by) gen8_ggtt_insert_entries at /home/pf/work/devel/own/pf-kernel/linux/drivers/gpu/drm/i915/gt/intel_ggtt.c:300
> 
> Probably, recent PTE-related changes are relevant:
> 
> $ git log --oneline --no-merges v6.4..v6.5 -- drivers/gpu/drm/i915/gt/intel_ggtt.c
> 3532e75dfadcf drm/i915/uc: perma-pin firmwares
> 4722e2ebe6f21 drm/i915/gt: Fix second parameter type of pre-gen8 pte_encode callbacks
> 9275277d53248 drm/i915: use pat_index instead of cache_level
> 5e352e32aec23 drm/i915: preparation for using PAT index
> 341ad0e8e2542 drm/i915/mtl: Add PTE encode function
> 
> Also note Lenovo T14s laptop with TigerLake-LP GT2 [Iris Xe Graphics] (rev 01) is not affected by this issue.
> 
> Full dmesg with DRM debug enabled is available in the bugreport I've reported earlier [1]. I'm sending this email to make the issue more visible.
> 
> [1] https://gitlab.freedesktop.org/drm/intel/-/issues/9256
> 

Thanks for the regression report. I'm adding it to regzbot:

#regzbot ^introduced: 0b62af28f249b9
#regzbot title: gen8_ggtt_insert_entries() panic on Lenovo T14s (Tiger Lake) due to folio_batch() on shmem_sg_free_table()
#regzbot link: https://gitlab.freedesktop.org/drm/intel/-/issues/9256

-- 
An old man doll... just what I always wanted! - Clara

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