Hey.
The dump stack is next, also I printed the vmid and gen_type:
(XEN) HVM2: vGT error:(vgt_decode_fb_format:443) pdev->gen_dev_type = 0
(XEN) HVM2: vGT error:(vgt_decode_fb_format:444) vmid = 0
(XEN) HVM2: ------------[ cut here ]------------
(XEN) HVM2: WARNING: CPU: 0 PID: 1910 at drivers/xen/vgt/fb_decoder.c:445 vgt_decode_fb_fo
(XEN) HVM2: rmat+0x76/0x397()
(XEN) HVM2: Modules linked in: fuse microcode serio_raw i2c_piix4 ppdev parport_pc mperf f
(XEN) HVM2: req_table lp parport ext4 crc16 jbd2 mbcache uhci_hcd ata_generic pata_acpi
(XEN) HVM2: CPU: 0 PID: 1910 Comm: Xorg Tainted: GÂÂÂÂÂÂÂ WÂÂÂ 3.11.6-vgt+ #6
(XEN) HVM2: Hardware name: Xen HVM domU, BIOS 4.3.1 01/02/2016
(XEN) HVM2:Â 0000000000000000 ffff880034c4bcb8 ffffffff814f818d 0000000000000000
(XEN) HVM2:Â ffff880034c4bcf0 ffffffff81054832 ffffffff812cd9de 0000000000000000
(XEN) HVM2:Â ffff8800356bfc00 ffff88003730a800 ffffc90000500000 ffff880034c4bd00
(XEN) HVM2: Call Trace:
(XEN) HVM2:Â [<ffffffff814f818d>] dump_stack+0x45/0x56
(XEN) HVM2:Â [<ffffffff81054832>] warn_slowpath_common+0x7a/0x93
(XEN) HVM2:Â [<ffffffff812cd9de>] ? vgt_decode_fb_format+0x76/0x397
(XEN) HVM2:Â [<ffffffff810548ea>] warn_slowpath_null+0x15/0x17
(XEN) HVM2:Â [<ffffffff812cd9de>] vgt_decode_fb_format+0x76/0x397
(XEN) HVM2:Â [<ffffffff8130bd22>] ? drm_ut_debug_printk+0x56/0x5d
(XEN) HVM2:Â [<ffffffff81121b7c>] ? kmem_cache_alloc_trace+0x2d/0xee
(XEN) HVM2:Â [<ffffffff81337af3>] i915_gem_vgtbuffer_ioctl+0xa3/0x6d7
(XEN) HVM2:Â [<ffffffff81307243>] drm_ioctl+0x2ef/0x41f
(XEN) HVM2:Â [<ffffffff81337a50>] ? i915_gem_vgtbuffer_mn_invalidate_range_start+0xce/0xce
(XEN) HVM2:
(XEN) HVM2:Â [<ffffffff8113fb68>] ? mntput_no_expire+0x75/0x10f
(XEN) HVM2:Â [<ffffffff81135ed6>] vfs_ioctl+0x18/0x34
(XEN) HVM2:Â [<ffffffff8113668b>] do_vfs_ioctl+0x328/0x3dd
(XEN) HVM2:Â [<ffffffff81129859>] ? ____fput+0x9/0xb
(XEN) HVM2:Â [<ffffffff8106c49f>] ? task_work_run+0x7d/0x8e
(XEN) HVM2:Â [<ffffffff81136792>] SyS_ioctl+0x52/0x7d
(XEN) HVM2:Â [<ffffffff81502a07>] ? do_page_fault+0x9/0xb
(XEN) HVM2:Â [<ffffffff81505f29>] system_call_fastpath+0x16/0x1b
(XEN) HVM2: ---[ end trace 0379a71d228ab663 ]---
(XEN) HVM2: vGT error:(vgt_decode_fb_format:448) Only HSW / VLV / IVB is supported now
Strange for me was that I got vmid=0 and gen_type=0, so I decided go to i915_gem_vgtbuffer_ioctl and write next at the start:
if (!xen_initial_domain()) { return -EPERM; }
Also same code is in 3.17 kernel from XenGT-kernel repo.
it seems that there is no more this error now( from vgt_fb_decoder ), BUT there is often freeze or very laggy UI in guest.
What it can be?
With best regards,
ÂOleksii